Merge commit 'ab802d5f2319768f8250c1a8819e327e2f9f2843' into master

Update matplotlib-cpp, and make it work with the sandboxed python

Change-Id: Ie9836993f9ab6f8f28877e5958d4b4f119db4632
diff --git a/third_party/matplotlib-cpp/matplotlibcpp.h b/third_party/matplotlib-cpp/matplotlibcpp.h
index eb7b7cc..35aeb54 100644
--- a/third_party/matplotlib-cpp/matplotlibcpp.h
+++ b/third_party/matplotlib-cpp/matplotlibcpp.h
@@ -1,26 +1,41 @@
 #pragma once
 
+// Python headers must be included before any system headers, since
+// they define _POSIX_C_SOURCE
+#include <Python.h>
+
 #include <vector>
 #include <map>
+#include <array>
 #include <numeric>
 #include <algorithm>
 #include <stdexcept>
 #include <iostream>
-#include <stdint.h> // <cstdint> requires c++11 support
-
-#if __cplusplus > 199711L || _MSC_VER > 1800
-#  include <functional>
-#endif
-
-#include <Python.h>
+#include <cstdint> // <cstdint> requires c++11 support
+#include <functional>
 
 #ifndef WITHOUT_NUMPY
 #  define NPY_NO_DEPRECATED_API NPY_1_7_API_VERSION
 #  include <numpy/arrayobject.h>
+
+#  ifdef WITH_OPENCV
+#    include <opencv2/opencv.hpp>
+#  endif // WITH_OPENCV
+
+/*
+ * A bunch of constants were removed in OpenCV 4 in favour of enum classes, so
+ * define the ones we need here.
+ */
+#  if CV_MAJOR_VERSION > 3
+#    define CV_BGR2RGB cv::COLOR_BGR2RGB
+#    define CV_BGRA2RGBA cv::COLOR_BGRA2RGBA
+#  endif
 #endif // WITHOUT_NUMPY
 
 #if PY_MAJOR_VERSION >= 3
 #  define PyString_FromString PyUnicode_FromString
+#  define PyInt_FromLong PyLong_FromLong
+#  define PyString_FromString PyUnicode_FromString
 #endif
 
 
@@ -30,28 +45,46 @@
 static std::string s_backend;
 
 struct _interpreter {
+    PyObject* s_python_function_arrow;
     PyObject *s_python_function_show;
     PyObject *s_python_function_close;
     PyObject *s_python_function_draw;
     PyObject *s_python_function_pause;
     PyObject *s_python_function_save;
     PyObject *s_python_function_figure;
+    PyObject *s_python_function_fignum_exists;
     PyObject *s_python_function_plot;
+    PyObject *s_python_function_quiver;
+    PyObject* s_python_function_contour;
     PyObject *s_python_function_semilogx;
     PyObject *s_python_function_semilogy;
     PyObject *s_python_function_loglog;
+    PyObject *s_python_function_fill;
     PyObject *s_python_function_fill_between;
     PyObject *s_python_function_hist;
+    PyObject *s_python_function_imshow;
+    PyObject *s_python_function_scatter;
+    PyObject *s_python_function_boxplot;
     PyObject *s_python_function_subplot;
+    PyObject *s_python_function_subplot2grid;
     PyObject *s_python_function_legend;
     PyObject *s_python_function_xlim;
     PyObject *s_python_function_ion;
+    PyObject *s_python_function_ginput;
     PyObject *s_python_function_ylim;
     PyObject *s_python_function_title;
     PyObject *s_python_function_axis;
+    PyObject *s_python_function_axvline;
+    PyObject *s_python_function_axvspan;
     PyObject *s_python_function_xlabel;
     PyObject *s_python_function_ylabel;
+    PyObject *s_python_function_gca;
+    PyObject *s_python_function_xticks;
+    PyObject *s_python_function_yticks;
+    PyObject* s_python_function_margins;
+    PyObject *s_python_function_tick_params;
     PyObject *s_python_function_grid;
+    PyObject* s_python_function_cla;
     PyObject *s_python_function_clf;
     PyObject *s_python_function_errorbar;
     PyObject *s_python_function_annotate;
@@ -60,6 +93,12 @@
     PyObject *s_python_empty_tuple;
     PyObject *s_python_function_stem;
     PyObject *s_python_function_xkcd;
+    PyObject *s_python_function_text;
+    PyObject *s_python_function_suptitle;
+    PyObject *s_python_function_bar;
+    PyObject *s_python_function_colorbar;
+    PyObject *s_python_function_subplots_adjust;
+
 
     /* For now, _interpreter is implemented as a singleton since its currently not possible to have
        multiple independent embedded python interpreters without patching the python source code
@@ -72,6 +111,18 @@
         return ctx;
     }
 
+    PyObject* safe_import(PyObject* module, std::string fname) {
+        PyObject* fn = PyObject_GetAttrString(module, fname.c_str());
+
+        if (!fn)
+            throw std::runtime_error(std::string("Couldn't find required function: ") + fname);
+
+        if (!PyFunction_Check(fn))
+            throw std::runtime_error(fname + std::string(" is unexpectedly not a PyFunction."));
+
+        return fn;
+    }
+
 private:
 
 #ifndef WITHOUT_NUMPY
@@ -92,6 +143,29 @@
 #endif
 
     _interpreter() {
+      // Force PYTHONHOME and PYTHONPATH to our sandboxed python.
+      wchar_t python_home[] = L"../python_repo/usr/";
+      wchar_t python_path[] =
+          L"../matplotlib_repo/3:../python_repo/usr/lib/python35.zip:../"
+          L"python_repo/usr/lib/python3.5:../python_repo/usr/lib/python3.5/"
+          L"plat-x86_64-linux-gnu:../python_repo/usr/lib/python3.5/"
+          L"lib-dynload:../python_repo/usr/lib/python3/dist-packages";
+
+      Py_SetPath(python_path);
+      Py_SetPythonHome(python_home);
+
+      // We fail really poorly if DISPLAY isn't set.  We can do better.
+      if (getenv("DISPLAY") == nullptr) {
+        fprintf(stderr, "DISPLAY not set\n");
+        abort();
+      }
+
+      // TODO(austin): Confirm LD_LIBRARY_PATH does the right thing.  Can't
+      // hurt.
+      setenv("LD_LIBRARY_PATH",
+             "../python_repo/lib/x86_64-linux-gnu:../python_repo/usr/lib:../"
+             "python_repo/usr/lib/x86_64-linux-gnu", 0);
+      Py_DontWriteBytecodeFlag = 1;
 
         // optional but recommended
 #if PY_MAJOR_VERSION >= 3
@@ -108,18 +182,18 @@
 
         PyObject* matplotlibname = PyString_FromString("matplotlib");
         PyObject* pyplotname = PyString_FromString("matplotlib.pyplot");
-        PyObject* mpl_toolkits = PyString_FromString("mpl_toolkits");
-        PyObject* axis3d = PyString_FromString("mpl_toolkits.mplot3d");
-        PyObject* pylabname  = PyString_FromString("pylab");
         PyObject* cmname  = PyString_FromString("matplotlib.cm");
-        if (!pyplotname || !pylabname || !matplotlibname || !mpl_toolkits ||
-            !axis3d || !cmname) {
-          throw std::runtime_error("couldnt create string");
+        PyObject* pylabname  = PyString_FromString("pylab");
+        if (!pyplotname || !pylabname || !matplotlibname || !cmname) {
+            throw std::runtime_error("couldnt create string");
         }
 
         PyObject* matplotlib = PyImport_Import(matplotlibname);
         Py_DECREF(matplotlibname);
-        if (!matplotlib) { throw std::runtime_error("Error loading module matplotlib!"); }
+        if (!matplotlib) {
+            PyErr_Print();
+            throw std::runtime_error("Error loading module matplotlib!");
+        }
 
         // matplotlib.use() must be called *before* pylab, matplotlib.pyplot,
         // or matplotlib.backends is imported for the first time
@@ -139,102 +213,59 @@
         Py_DECREF(pylabname);
         if (!pylabmod) { throw std::runtime_error("Error loading module pylab!"); }
 
-        PyObject* mpl_toolkitsmod = PyImport_Import(mpl_toolkits);
-        Py_DECREF(mpl_toolkitsmod);
-        if (!mpl_toolkitsmod) { throw std::runtime_error("Error loading module mpl_toolkits!"); }
-
-        PyObject* axis3dmod = PyImport_Import(axis3d);
-        Py_DECREF(axis3dmod);
-        if (!axis3dmod) { throw std::runtime_error("Error loading module mpl_toolkits.mplot3d!"); }
-
-        s_python_function_show = PyObject_GetAttrString(pymod, "show");
-        s_python_function_close = PyObject_GetAttrString(pymod, "close");
-        s_python_function_draw = PyObject_GetAttrString(pymod, "draw");
-        s_python_function_pause = PyObject_GetAttrString(pymod, "pause");
-        s_python_function_figure = PyObject_GetAttrString(pymod, "figure");
-        s_python_function_plot = PyObject_GetAttrString(pymod, "plot");
-        s_python_function_semilogx = PyObject_GetAttrString(pymod, "semilogx");
-        s_python_function_semilogy = PyObject_GetAttrString(pymod, "semilogy");
-        s_python_function_loglog = PyObject_GetAttrString(pymod, "loglog");
-        s_python_function_fill_between = PyObject_GetAttrString(pymod, "fill_between");
-        s_python_function_hist = PyObject_GetAttrString(pymod,"hist");
-        s_python_function_subplot = PyObject_GetAttrString(pymod, "subplot");
-        s_python_function_legend = PyObject_GetAttrString(pymod, "legend");
-        s_python_function_ylim = PyObject_GetAttrString(pymod, "ylim");
-        s_python_function_title = PyObject_GetAttrString(pymod, "title");
-        s_python_function_axis = PyObject_GetAttrString(pymod, "axis");
-        s_python_function_xlabel = PyObject_GetAttrString(pymod, "xlabel");
-        s_python_function_ylabel = PyObject_GetAttrString(pymod, "ylabel");
-        s_python_function_grid = PyObject_GetAttrString(pymod, "grid");
-        s_python_function_xlim = PyObject_GetAttrString(pymod, "xlim");
-        s_python_function_ion = PyObject_GetAttrString(pymod, "ion");
-        s_python_function_save = PyObject_GetAttrString(pylabmod, "savefig");
-        s_python_function_annotate = PyObject_GetAttrString(pymod,"annotate");
-        s_python_function_clf = PyObject_GetAttrString(pymod, "clf");
-        s_python_function_errorbar = PyObject_GetAttrString(pymod, "errorbar");
-        s_python_function_tight_layout = PyObject_GetAttrString(pymod, "tight_layout");
-        s_python_function_stem = PyObject_GetAttrString(pymod, "stem");
-        s_python_function_xkcd = PyObject_GetAttrString(pymod, "xkcd");
-
-        if(    !s_python_function_show
-            || !s_python_function_close
-            || !s_python_function_draw
-            || !s_python_function_pause
-            || !s_python_function_figure
-            || !s_python_function_plot
-            || !s_python_function_semilogx
-            || !s_python_function_semilogy
-            || !s_python_function_loglog
-            || !s_python_function_fill_between
-            || !s_python_function_subplot
-            || !s_python_function_legend
-            || !s_python_function_ylim
-            || !s_python_function_title
-            || !s_python_function_axis
-            || !s_python_function_xlabel
-            || !s_python_function_ylabel
-            || !s_python_function_grid
-            || !s_python_function_xlim
-            || !s_python_function_ion
-            || !s_python_function_save
-            || !s_python_function_clf
-            || !s_python_function_annotate
-            || !s_python_function_errorbar
-            || !s_python_function_errorbar
-            || !s_python_function_tight_layout
-            || !s_python_function_stem
-            || !s_python_function_xkcd
-        ) { throw std::runtime_error("Couldn't find required function!"); }
-
-        if (   !PyFunction_Check(s_python_function_show)
-            || !PyFunction_Check(s_python_function_close)
-            || !PyFunction_Check(s_python_function_draw)
-            || !PyFunction_Check(s_python_function_pause)
-            || !PyFunction_Check(s_python_function_figure)
-            || !PyFunction_Check(s_python_function_plot)
-            || !PyFunction_Check(s_python_function_semilogx)
-            || !PyFunction_Check(s_python_function_semilogy)
-            || !PyFunction_Check(s_python_function_loglog)
-            || !PyFunction_Check(s_python_function_fill_between)
-            || !PyFunction_Check(s_python_function_subplot)
-            || !PyFunction_Check(s_python_function_legend)
-            || !PyFunction_Check(s_python_function_annotate)
-            || !PyFunction_Check(s_python_function_ylim)
-            || !PyFunction_Check(s_python_function_title)
-            || !PyFunction_Check(s_python_function_axis)
-            || !PyFunction_Check(s_python_function_xlabel)
-            || !PyFunction_Check(s_python_function_ylabel)
-            || !PyFunction_Check(s_python_function_grid)
-            || !PyFunction_Check(s_python_function_xlim)
-            || !PyFunction_Check(s_python_function_ion)
-            || !PyFunction_Check(s_python_function_save)
-            || !PyFunction_Check(s_python_function_clf)
-            || !PyFunction_Check(s_python_function_tight_layout)
-            || !PyFunction_Check(s_python_function_errorbar)
-            || !PyFunction_Check(s_python_function_stem)
-            || !PyFunction_Check(s_python_function_xkcd)
-        ) { throw std::runtime_error("Python object is unexpectedly not a PyFunction."); }
-
+        s_python_function_arrow = safe_import(pymod, "arrow");
+        s_python_function_show = safe_import(pymod, "show");
+        s_python_function_close = safe_import(pymod, "close");
+        s_python_function_draw = safe_import(pymod, "draw");
+        s_python_function_pause = safe_import(pymod, "pause");
+        s_python_function_figure = safe_import(pymod, "figure");
+        s_python_function_fignum_exists = safe_import(pymod, "fignum_exists");
+        s_python_function_plot = safe_import(pymod, "plot");
+        s_python_function_quiver = safe_import(pymod, "quiver");
+        s_python_function_contour = safe_import(pymod, "contour");
+        s_python_function_semilogx = safe_import(pymod, "semilogx");
+        s_python_function_semilogy = safe_import(pymod, "semilogy");
+        s_python_function_loglog = safe_import(pymod, "loglog");
+        s_python_function_fill = safe_import(pymod, "fill");
+        s_python_function_fill_between = safe_import(pymod, "fill_between");
+        s_python_function_hist = safe_import(pymod,"hist");
+        s_python_function_scatter = safe_import(pymod,"scatter");
+        s_python_function_boxplot = safe_import(pymod,"boxplot");
+        s_python_function_subplot = safe_import(pymod, "subplot");
+        s_python_function_subplot2grid = safe_import(pymod, "subplot2grid");
+        s_python_function_legend = safe_import(pymod, "legend");
+        s_python_function_ylim = safe_import(pymod, "ylim");
+        s_python_function_title = safe_import(pymod, "title");
+        s_python_function_axis = safe_import(pymod, "axis");
+        s_python_function_axvline = safe_import(pymod, "axvline");
+        s_python_function_axvspan = safe_import(pymod, "axvspan");
+        s_python_function_xlabel = safe_import(pymod, "xlabel");
+        s_python_function_ylabel = safe_import(pymod, "ylabel");
+        s_python_function_gca = safe_import(pymod, "gca");
+        s_python_function_xticks = safe_import(pymod, "xticks");
+        s_python_function_yticks = safe_import(pymod, "yticks");
+        s_python_function_margins = safe_import(pymod, "margins");
+        s_python_function_tick_params = safe_import(pymod, "tick_params");
+        s_python_function_grid = safe_import(pymod, "grid");
+        s_python_function_xlim = safe_import(pymod, "xlim");
+        s_python_function_ion = safe_import(pymod, "ion");
+        s_python_function_ginput = safe_import(pymod, "ginput");
+        s_python_function_save = safe_import(pylabmod, "savefig");
+        s_python_function_annotate = safe_import(pymod,"annotate");
+        s_python_function_cla = safe_import(pymod, "cla");
+        s_python_function_clf = safe_import(pymod, "clf");
+        s_python_function_errorbar = safe_import(pymod, "errorbar");
+        s_python_function_tight_layout = safe_import(pymod, "tight_layout");
+        s_python_function_stem = safe_import(pymod, "stem");
+        s_python_function_xkcd = safe_import(pymod, "xkcd");
+        s_python_function_text = safe_import(pymod, "text");
+        s_python_function_suptitle = safe_import(pymod, "suptitle");
+        s_python_function_bar = safe_import(pymod,"bar");
+        s_python_function_colorbar = PyObject_GetAttrString(pymod, "colorbar");
+        s_python_function_subplots_adjust = safe_import(pymod,"subplots_adjust");
+#ifndef WITHOUT_NUMPY
+        s_python_function_imshow = safe_import(pymod, "imshow");
+#endif
         s_python_empty_tuple = PyTuple_New(0);
     }
 
@@ -245,7 +276,15 @@
 
 } // end namespace detail
 
-// must be called before the first regular call to matplotlib to have any effect
+/// Select the backend
+///
+/// **NOTE:** This must be called before the first plot command to have
+/// any effect.
+///
+/// Mainly useful to select the non-interactive 'Agg' backend when running
+/// matplotlibcpp in headless mode, for example on a machine with no display.
+///
+/// See also: https://matplotlib.org/2.0.2/api/matplotlib_configuration_api.html#matplotlib.use
 inline void backend(const std::string& name)
 {
     detail::s_backend = name;
@@ -253,6 +292,8 @@
 
 inline bool annotate(std::string annotation, double x, double y)
 {
+    detail::_interpreter::get();
+
     PyObject * xy = PyTuple_New(2);
     PyObject * str = PyString_FromString(annotation.c_str());
 
@@ -275,6 +316,8 @@
     return res;
 }
 
+namespace detail {
+
 #ifndef WITHOUT_NUMPY
 // Type selector for numpy array conversion
 template <typename T> struct select_npy_type { const static NPY_TYPES type = NPY_NOTYPE; }; //Default
@@ -290,29 +333,37 @@
 template <> struct select_npy_type<uint32_t> { const static NPY_TYPES type = NPY_ULONG; };
 template <> struct select_npy_type<uint64_t> { const static NPY_TYPES type = NPY_UINT64; };
 
+// Sanity checks; comment them out or change the numpy type below if you're compiling on
+// a platform where they don't apply
+static_assert(sizeof(long long) == 8);
+template <> struct select_npy_type<long long> { const static NPY_TYPES type = NPY_INT64; };
+static_assert(sizeof(unsigned long long) == 8);
+template <> struct select_npy_type<unsigned long long> { const static NPY_TYPES type = NPY_UINT64; };
+// TODO: add int, long, etc.
+
 template<typename Numeric>
 PyObject* get_array(const std::vector<Numeric>& v)
 {
-    detail::_interpreter::get();    //interpreter needs to be initialized for the numpy commands to work
+    npy_intp vsize = v.size();
     NPY_TYPES type = select_npy_type<Numeric>::type;
-    if (type == NPY_NOTYPE)
-    {
-        std::vector<double> vd(v.size());
-        npy_intp vsize = v.size();
-        std::copy(v.begin(),v.end(),vd.begin());
-        PyObject* varray = PyArray_SimpleNewFromData(1, &vsize, NPY_DOUBLE, (void*)(vd.data()));
+    if (type == NPY_NOTYPE) {
+        size_t memsize = v.size()*sizeof(double);
+        double* dp = static_cast<double*>(::malloc(memsize));
+        for (size_t i=0; i<v.size(); ++i)
+            dp[i] = v[i];
+        PyObject* varray = PyArray_SimpleNewFromData(1, &vsize, NPY_DOUBLE, dp);
+        PyArray_UpdateFlags(reinterpret_cast<PyArrayObject*>(varray), NPY_ARRAY_OWNDATA);
         return varray;
     }
-
-    npy_intp vsize = v.size();
+    
     PyObject* varray = PyArray_SimpleNewFromData(1, &vsize, type, (void*)(v.data()));
     return varray;
 }
 
+
 template<typename Numeric>
 PyObject* get_2darray(const std::vector<::std::vector<Numeric>>& v)
 {
-    detail::_interpreter::get();    //interpreter needs to be initialized for the numpy commands to work
     if (v.size() < 1) throw std::runtime_error("get_2d_array v too small");
 
     npy_intp vsize[2] = {static_cast<npy_intp>(v.size()),
@@ -347,14 +398,42 @@
 
 #endif // WITHOUT_NUMPY
 
+// sometimes, for labels and such, we need string arrays
+inline PyObject * get_array(const std::vector<std::string>& strings)
+{
+  PyObject* list = PyList_New(strings.size());
+  for (std::size_t i = 0; i < strings.size(); ++i) {
+    PyList_SetItem(list, i, PyString_FromString(strings[i].c_str()));
+  }
+  return list;
+}
+
+// not all matplotlib need 2d arrays, some prefer lists of lists
+template<typename Numeric>
+PyObject* get_listlist(const std::vector<std::vector<Numeric>>& ll)
+{
+  PyObject* listlist = PyList_New(ll.size());
+  for (std::size_t i = 0; i < ll.size(); ++i) {
+    PyList_SetItem(listlist, i, get_array(ll[i]));
+  }
+  return listlist;
+}
+
+} // namespace detail
+
+/// Plot a line through the given x and y data points..
+/// 
+/// See: https://matplotlib.org/3.2.1/api/_as_gen/matplotlib.pyplot.plot.html
 template<typename Numeric>
 bool plot(const std::vector<Numeric> &x, const std::vector<Numeric> &y, const std::map<std::string, std::string>& keywords)
 {
     assert(x.size() == y.size());
 
+    detail::_interpreter::get();
+
     // using numpy arrays
-    PyObject* xarray = get_array(x);
-    PyObject* yarray = get_array(y);
+    PyObject* xarray = detail::get_array(x);
+    PyObject* yarray = detail::get_array(y);
 
     // construct positional args
     PyObject* args = PyTuple_New(2);
@@ -377,19 +456,46 @@
     return res;
 }
 
+// TODO - it should be possible to make this work by implementing
+// a non-numpy alternative for `detail::get_2darray()`.
+#ifndef WITHOUT_NUMPY
 template <typename Numeric>
 void plot_surface(const std::vector<::std::vector<Numeric>> &x,
                   const std::vector<::std::vector<Numeric>> &y,
                   const std::vector<::std::vector<Numeric>> &z,
                   const std::map<std::string, std::string> &keywords =
-                      std::map<std::string, std::string>()) {
+                      std::map<std::string, std::string>())
+{
+  detail::_interpreter::get();
+
+  // We lazily load the modules here the first time this function is called
+  // because I'm not sure that we can assume "matplotlib installed" implies
+  // "mpl_toolkits installed" on all platforms, and we don't want to require
+  // it for people who don't need 3d plots.
+  static PyObject *mpl_toolkitsmod = nullptr, *axis3dmod = nullptr;
+  if (!mpl_toolkitsmod) {
+    detail::_interpreter::get();
+
+    PyObject* mpl_toolkits = PyString_FromString("mpl_toolkits");
+    PyObject* axis3d = PyString_FromString("mpl_toolkits.mplot3d");
+    if (!mpl_toolkits || !axis3d) { throw std::runtime_error("couldnt create string"); }
+
+    mpl_toolkitsmod = PyImport_Import(mpl_toolkits);
+    Py_DECREF(mpl_toolkits);
+    if (!mpl_toolkitsmod) { throw std::runtime_error("Error loading module mpl_toolkits!"); }
+
+    axis3dmod = PyImport_Import(axis3d);
+    Py_DECREF(axis3d);
+    if (!axis3dmod) { throw std::runtime_error("Error loading module mpl_toolkits.mplot3d!"); }
+  }
+
   assert(x.size() == y.size());
   assert(y.size() == z.size());
 
   // using numpy arrays
-  PyObject *xarray = get_2darray(x);
-  PyObject *yarray = get_2darray(y);
-  PyObject *zarray = get_2darray(z);
+  PyObject *xarray = detail::get_2darray(x);
+  PyObject *yarray = detail::get_2darray(y);
+  PyObject *zarray = detail::get_2darray(z);
 
   // construct positional args
   PyObject *args = PyTuple_New(3);
@@ -446,15 +552,103 @@
   Py_DECREF(kwargs);
   if (res) Py_DECREF(res);
 }
+#endif // WITHOUT_NUMPY
+
+template <typename Numeric>
+void plot3(const std::vector<Numeric> &x,
+                  const std::vector<Numeric> &y,
+                  const std::vector<Numeric> &z,
+                  const std::map<std::string, std::string> &keywords =
+                      std::map<std::string, std::string>())
+{
+  detail::_interpreter::get();
+
+  // Same as with plot_surface: We lazily load the modules here the first time 
+  // this function is called because I'm not sure that we can assume "matplotlib 
+  // installed" implies "mpl_toolkits installed" on all platforms, and we don't 
+  // want to require it for people who don't need 3d plots.
+  static PyObject *mpl_toolkitsmod = nullptr, *axis3dmod = nullptr;
+  if (!mpl_toolkitsmod) {
+    detail::_interpreter::get();
+
+    PyObject* mpl_toolkits = PyString_FromString("mpl_toolkits");
+    PyObject* axis3d = PyString_FromString("mpl_toolkits.mplot3d");
+    if (!mpl_toolkits || !axis3d) { throw std::runtime_error("couldnt create string"); }
+
+    mpl_toolkitsmod = PyImport_Import(mpl_toolkits);
+    Py_DECREF(mpl_toolkits);
+    if (!mpl_toolkitsmod) { throw std::runtime_error("Error loading module mpl_toolkits!"); }
+
+    axis3dmod = PyImport_Import(axis3d);
+    Py_DECREF(axis3d);
+    if (!axis3dmod) { throw std::runtime_error("Error loading module mpl_toolkits.mplot3d!"); }
+  }
+
+  assert(x.size() == y.size());
+  assert(y.size() == z.size());
+
+  PyObject *xarray = detail::get_array(x);
+  PyObject *yarray = detail::get_array(y);
+  PyObject *zarray = detail::get_array(z);
+
+  // construct positional args
+  PyObject *args = PyTuple_New(3);
+  PyTuple_SetItem(args, 0, xarray);
+  PyTuple_SetItem(args, 1, yarray);
+  PyTuple_SetItem(args, 2, zarray);
+
+  // Build up the kw args.
+  PyObject *kwargs = PyDict_New();
+
+  for (std::map<std::string, std::string>::const_iterator it = keywords.begin();
+       it != keywords.end(); ++it) {
+    PyDict_SetItemString(kwargs, it->first.c_str(),
+                         PyString_FromString(it->second.c_str()));
+  }
+
+  PyObject *fig =
+      PyObject_CallObject(detail::_interpreter::get().s_python_function_figure,
+                          detail::_interpreter::get().s_python_empty_tuple);
+  if (!fig) throw std::runtime_error("Call to figure() failed.");
+
+  PyObject *gca_kwargs = PyDict_New();
+  PyDict_SetItemString(gca_kwargs, "projection", PyString_FromString("3d"));
+
+  PyObject *gca = PyObject_GetAttrString(fig, "gca");
+  if (!gca) throw std::runtime_error("No gca");
+  Py_INCREF(gca);
+  PyObject *axis = PyObject_Call(
+      gca, detail::_interpreter::get().s_python_empty_tuple, gca_kwargs);
+
+  if (!axis) throw std::runtime_error("No axis");
+  Py_INCREF(axis);
+
+  Py_DECREF(gca);
+  Py_DECREF(gca_kwargs);
+
+  PyObject *plot3 = PyObject_GetAttrString(axis, "plot");
+  if (!plot3) throw std::runtime_error("No 3D line plot");
+  Py_INCREF(plot3);
+  PyObject *res = PyObject_Call(plot3, args, kwargs);
+  if (!res) throw std::runtime_error("Failed 3D line plot");
+  Py_DECREF(plot3);
+
+  Py_DECREF(axis);
+  Py_DECREF(args);
+  Py_DECREF(kwargs);
+  if (res) Py_DECREF(res);
+}
 
 template<typename Numeric>
 bool stem(const std::vector<Numeric> &x, const std::vector<Numeric> &y, const std::map<std::string, std::string>& keywords)
 {
     assert(x.size() == y.size());
 
+    detail::_interpreter::get();
+
     // using numpy arrays
-    PyObject* xarray = get_array(x);
-    PyObject* yarray = get_array(y);
+    PyObject* xarray = detail::get_array(x);
+    PyObject* yarray = detail::get_array(y);
 
     // construct positional args
     PyObject* args = PyTuple_New(2);
@@ -481,15 +675,49 @@
 }
 
 template< typename Numeric >
+bool fill(const std::vector<Numeric>& x, const std::vector<Numeric>& y, const std::map<std::string, std::string>& keywords)
+{
+    assert(x.size() == y.size());
+
+    detail::_interpreter::get();
+
+    // using numpy arrays
+    PyObject* xarray = detail::get_array(x);
+    PyObject* yarray = detail::get_array(y);
+
+    // construct positional args
+    PyObject* args = PyTuple_New(2);
+    PyTuple_SetItem(args, 0, xarray);
+    PyTuple_SetItem(args, 1, yarray);
+
+    // construct keyword args
+    PyObject* kwargs = PyDict_New();
+    for (auto it = keywords.begin(); it != keywords.end(); ++it) {
+        PyDict_SetItemString(kwargs, it->first.c_str(), PyUnicode_FromString(it->second.c_str()));
+    }
+
+    PyObject* res = PyObject_Call(detail::_interpreter::get().s_python_function_fill, args, kwargs);
+
+    Py_DECREF(args);
+    Py_DECREF(kwargs);
+
+    if (res) Py_DECREF(res);
+
+    return res;
+}
+
+template< typename Numeric >
 bool fill_between(const std::vector<Numeric>& x, const std::vector<Numeric>& y1, const std::vector<Numeric>& y2, const std::map<std::string, std::string>& keywords)
 {
     assert(x.size() == y1.size());
     assert(x.size() == y2.size());
 
+    detail::_interpreter::get();
+
     // using numpy arrays
-    PyObject* xarray = get_array(x);
-    PyObject* y1array = get_array(y1);
-    PyObject* y2array = get_array(y2);
+    PyObject* xarray = detail::get_array(x);
+    PyObject* y1array = detail::get_array(y1);
+    PyObject* y2array = detail::get_array(y2);
 
     // construct positional args
     PyObject* args = PyTuple_New(3);
@@ -499,8 +727,7 @@
 
     // construct keyword args
     PyObject* kwargs = PyDict_New();
-    for(std::map<std::string, std::string>::const_iterator it = keywords.begin(); it != keywords.end(); ++it)
-    {
+    for(std::map<std::string, std::string>::const_iterator it = keywords.begin(); it != keywords.end(); ++it) {
         PyDict_SetItemString(kwargs, it->first.c_str(), PyUnicode_FromString(it->second.c_str()));
     }
 
@@ -513,17 +740,50 @@
     return res;
 }
 
-template< typename Numeric>
-bool hist(const std::vector<Numeric>& y, long bins=10,std::string color="b", double alpha=1.0)
-{
+template <typename Numeric>
+bool arrow(Numeric x, Numeric y, Numeric end_x, Numeric end_y, const std::string& fc = "r",
+           const std::string ec = "k", Numeric head_length = 0.25, Numeric head_width = 0.1625) {
+    PyObject* obj_x = PyFloat_FromDouble(x);
+    PyObject* obj_y = PyFloat_FromDouble(y);
+    PyObject* obj_end_x = PyFloat_FromDouble(end_x);
+    PyObject* obj_end_y = PyFloat_FromDouble(end_y);
 
-    PyObject* yarray = get_array(y);
+    PyObject* kwargs = PyDict_New();
+    PyDict_SetItemString(kwargs, "fc", PyString_FromString(fc.c_str()));
+    PyDict_SetItemString(kwargs, "ec", PyString_FromString(ec.c_str()));
+    PyDict_SetItemString(kwargs, "head_width", PyFloat_FromDouble(head_width));
+    PyDict_SetItemString(kwargs, "head_length", PyFloat_FromDouble(head_length));
+
+    PyObject* plot_args = PyTuple_New(4);
+    PyTuple_SetItem(plot_args, 0, obj_x);
+    PyTuple_SetItem(plot_args, 1, obj_y);
+    PyTuple_SetItem(plot_args, 2, obj_end_x);
+    PyTuple_SetItem(plot_args, 3, obj_end_y);
+
+    PyObject* res =
+            PyObject_Call(detail::_interpreter::get().s_python_function_arrow, plot_args, kwargs);
+
+    Py_DECREF(plot_args);
+    Py_DECREF(kwargs);
+    if (res)
+        Py_DECREF(res);
+
+    return res;
+}
+
+template< typename Numeric>
+bool hist(const std::vector<Numeric>& y, long bins=10,std::string color="b",
+          double alpha=1.0, bool cumulative=false)
+{
+    detail::_interpreter::get();
+
+    PyObject* yarray = detail::get_array(y);
 
     PyObject* kwargs = PyDict_New();
     PyDict_SetItemString(kwargs, "bins", PyLong_FromLong(bins));
     PyDict_SetItemString(kwargs, "color", PyString_FromString(color.c_str()));
     PyDict_SetItemString(kwargs, "alpha", PyFloat_FromDouble(alpha));
-
+    PyDict_SetItemString(kwargs, "cumulative", cumulative ? Py_True : Py_False);
 
     PyObject* plot_args = PyTuple_New(1);
 
@@ -540,10 +800,263 @@
     return res;
 }
 
+#ifndef WITHOUT_NUMPY
+namespace detail {
+
+inline void imshow(void *ptr, const NPY_TYPES type, const int rows, const int columns, const int colors, const std::map<std::string, std::string> &keywords, PyObject** out)
+{
+    assert(type == NPY_UINT8 || type == NPY_FLOAT);
+    assert(colors == 1 || colors == 3 || colors == 4);
+
+    detail::_interpreter::get();
+
+    // construct args
+    npy_intp dims[3] = { rows, columns, colors };
+    PyObject *args = PyTuple_New(1);
+    PyTuple_SetItem(args, 0, PyArray_SimpleNewFromData(colors == 1 ? 2 : 3, dims, type, ptr));
+
+    // construct keyword args
+    PyObject* kwargs = PyDict_New();
+    for(std::map<std::string, std::string>::const_iterator it = keywords.begin(); it != keywords.end(); ++it)
+    {
+        PyDict_SetItemString(kwargs, it->first.c_str(), PyUnicode_FromString(it->second.c_str()));
+    }
+
+    PyObject *res = PyObject_Call(detail::_interpreter::get().s_python_function_imshow, args, kwargs);
+    Py_DECREF(args);
+    Py_DECREF(kwargs);
+    if (!res)
+        throw std::runtime_error("Call to imshow() failed");
+    if (out)
+        *out = res;
+    else
+        Py_DECREF(res);
+}
+
+} // namespace detail
+
+inline void imshow(const unsigned char *ptr, const int rows, const int columns, const int colors, const std::map<std::string, std::string> &keywords = {}, PyObject** out = nullptr)
+{
+    detail::imshow((void *) ptr, NPY_UINT8, rows, columns, colors, keywords, out);
+}
+
+inline void imshow(const float *ptr, const int rows, const int columns, const int colors, const std::map<std::string, std::string> &keywords = {}, PyObject** out = nullptr)
+{
+    detail::imshow((void *) ptr, NPY_FLOAT, rows, columns, colors, keywords, out);
+}
+
+#ifdef WITH_OPENCV
+void imshow(const cv::Mat &image, const std::map<std::string, std::string> &keywords = {})
+{
+    // Convert underlying type of matrix, if needed
+    cv::Mat image2;
+    NPY_TYPES npy_type = NPY_UINT8;
+    switch (image.type() & CV_MAT_DEPTH_MASK) {
+    case CV_8U:
+        image2 = image;
+        break;
+    case CV_32F:
+        image2 = image;
+        npy_type = NPY_FLOAT;
+        break;
+    default:
+        image.convertTo(image2, CV_MAKETYPE(CV_8U, image.channels()));
+    }
+
+    // If color image, convert from BGR to RGB
+    switch (image2.channels()) {
+    case 3:
+        cv::cvtColor(image2, image2, CV_BGR2RGB);
+        break;
+    case 4:
+        cv::cvtColor(image2, image2, CV_BGRA2RGBA);
+    }
+
+    detail::imshow(image2.data, npy_type, image2.rows, image2.cols, image2.channels(), keywords);
+}
+#endif // WITH_OPENCV
+#endif // WITHOUT_NUMPY
+
+template<typename NumericX, typename NumericY>
+bool scatter(const std::vector<NumericX>& x,
+             const std::vector<NumericY>& y,
+             const double s=1.0, // The marker size in points**2
+             const std::map<std::string, std::string> & keywords = {})
+{
+    detail::_interpreter::get();
+
+    assert(x.size() == y.size());
+
+    PyObject* xarray = detail::get_array(x);
+    PyObject* yarray = detail::get_array(y);
+
+    PyObject* kwargs = PyDict_New();
+    PyDict_SetItemString(kwargs, "s", PyLong_FromLong(s));
+    for (const auto& it : keywords)
+    {
+        PyDict_SetItemString(kwargs, it.first.c_str(), PyString_FromString(it.second.c_str()));
+    }
+
+    PyObject* plot_args = PyTuple_New(2);
+    PyTuple_SetItem(plot_args, 0, xarray);
+    PyTuple_SetItem(plot_args, 1, yarray);
+
+    PyObject* res = PyObject_Call(detail::_interpreter::get().s_python_function_scatter, plot_args, kwargs);
+
+    Py_DECREF(plot_args);
+    Py_DECREF(kwargs);
+    if(res) Py_DECREF(res);
+
+    return res;
+}
+
+template<typename Numeric>
+bool boxplot(const std::vector<std::vector<Numeric>>& data,
+             const std::vector<std::string>& labels = {},
+             const std::map<std::string, std::string> & keywords = {})
+{
+    detail::_interpreter::get();
+
+    PyObject* listlist = detail::get_listlist(data);
+    PyObject* args = PyTuple_New(1);
+    PyTuple_SetItem(args, 0, listlist);
+
+    PyObject* kwargs = PyDict_New();
+
+    // kwargs needs the labels, if there are (the correct number of) labels
+    if (!labels.empty() && labels.size() == data.size()) {
+        PyDict_SetItemString(kwargs, "labels", detail::get_array(labels));
+    }
+
+    // take care of the remaining keywords
+    for (const auto& it : keywords)
+    {
+        PyDict_SetItemString(kwargs, it.first.c_str(), PyString_FromString(it.second.c_str()));
+    }
+
+    PyObject* res = PyObject_Call(detail::_interpreter::get().s_python_function_boxplot, args, kwargs);
+
+    Py_DECREF(args);
+    Py_DECREF(kwargs);
+
+    if(res) Py_DECREF(res);
+
+    return res;
+}
+
+template<typename Numeric>
+bool boxplot(const std::vector<Numeric>& data,
+             const std::map<std::string, std::string> & keywords = {})
+{
+    detail::_interpreter::get();
+
+    PyObject* vector = detail::get_array(data);
+    PyObject* args = PyTuple_New(1);
+    PyTuple_SetItem(args, 0, vector);
+
+    PyObject* kwargs = PyDict_New();
+    for (const auto& it : keywords)
+    {
+        PyDict_SetItemString(kwargs, it.first.c_str(), PyString_FromString(it.second.c_str()));
+    }
+
+    PyObject* res = PyObject_Call(detail::_interpreter::get().s_python_function_boxplot, args, kwargs);
+
+    Py_DECREF(args);
+    Py_DECREF(kwargs);
+
+    if(res) Py_DECREF(res);
+
+    return res;
+}
+
+template <typename Numeric>
+bool bar(const std::vector<Numeric> &               x,
+         const std::vector<Numeric> &               y,
+         std::string                                ec       = "black",
+         std::string                                ls       = "-",
+         double                                     lw       = 1.0,
+         const std::map<std::string, std::string> & keywords = {})
+{
+  detail::_interpreter::get();
+
+  PyObject * xarray = detail::get_array(x);
+  PyObject * yarray = detail::get_array(y);
+
+  PyObject * kwargs = PyDict_New();
+
+  PyDict_SetItemString(kwargs, "ec", PyString_FromString(ec.c_str()));
+  PyDict_SetItemString(kwargs, "ls", PyString_FromString(ls.c_str()));
+  PyDict_SetItemString(kwargs, "lw", PyFloat_FromDouble(lw));
+
+  for (std::map<std::string, std::string>::const_iterator it =
+         keywords.begin();
+       it != keywords.end();
+       ++it) {
+    PyDict_SetItemString(
+      kwargs, it->first.c_str(), PyUnicode_FromString(it->second.c_str()));
+  }
+
+  PyObject * plot_args = PyTuple_New(2);
+  PyTuple_SetItem(plot_args, 0, xarray);
+  PyTuple_SetItem(plot_args, 1, yarray);
+
+  PyObject * res = PyObject_Call(
+    detail::_interpreter::get().s_python_function_bar, plot_args, kwargs);
+
+  Py_DECREF(plot_args);
+  Py_DECREF(kwargs);
+  if (res) Py_DECREF(res);
+
+  return res;
+}
+
+template <typename Numeric>
+bool bar(const std::vector<Numeric> &               y,
+         std::string                                ec       = "black",
+         std::string                                ls       = "-",
+         double                                     lw       = 1.0,
+         const std::map<std::string, std::string> & keywords = {})
+{
+  using T = typename std::remove_reference<decltype(y)>::type::value_type;
+
+  detail::_interpreter::get();
+
+  std::vector<T> x;
+  for (std::size_t i = 0; i < y.size(); i++) { x.push_back(i); }
+
+  return bar(x, y, ec, ls, lw, keywords);
+}
+
+inline bool subplots_adjust(const std::map<std::string, double>& keywords = {})
+{
+    detail::_interpreter::get();
+
+    PyObject* kwargs = PyDict_New();
+    for (std::map<std::string, double>::const_iterator it =
+            keywords.begin(); it != keywords.end(); ++it) {
+        PyDict_SetItemString(kwargs, it->first.c_str(),
+                             PyFloat_FromDouble(it->second));
+    }
+
+
+    PyObject* plot_args = PyTuple_New(0);
+
+    PyObject* res = PyObject_Call(detail::_interpreter::get().s_python_function_subplots_adjust, plot_args, kwargs);
+
+    Py_DECREF(plot_args);
+    Py_DECREF(kwargs);
+    if(res) Py_DECREF(res);
+
+    return res;
+}
+
 template< typename Numeric>
 bool named_hist(std::string label,const std::vector<Numeric>& y, long bins=10, std::string color="b", double alpha=1.0)
 {
-    PyObject* yarray = get_array(y);
+    detail::_interpreter::get();
+
+    PyObject* yarray = detail::get_array(y);
 
     PyObject* kwargs = PyDict_New();
     PyDict_SetItemString(kwargs, "label", PyString_FromString(label.c_str()));
@@ -569,8 +1082,10 @@
 {
     assert(x.size() == y.size());
 
-    PyObject* xarray = get_array(x);
-    PyObject* yarray = get_array(y);
+    detail::_interpreter::get();
+
+    PyObject* xarray = detail::get_array(x);
+    PyObject* yarray = detail::get_array(y);
 
     PyObject* pystring = PyString_FromString(s.c_str());
 
@@ -587,13 +1102,84 @@
     return res;
 }
 
+template <typename NumericX, typename NumericY, typename NumericZ>
+bool contour(const std::vector<NumericX>& x, const std::vector<NumericY>& y,
+             const std::vector<NumericZ>& z,
+             const std::map<std::string, std::string>& keywords = {}) {
+    assert(x.size() == y.size() && x.size() == z.size());
+
+    PyObject* xarray = get_array(x);
+    PyObject* yarray = get_array(y);
+    PyObject* zarray = get_array(z);
+
+    PyObject* plot_args = PyTuple_New(3);
+    PyTuple_SetItem(plot_args, 0, xarray);
+    PyTuple_SetItem(plot_args, 1, yarray);
+    PyTuple_SetItem(plot_args, 2, zarray);
+
+    // construct keyword args
+    PyObject* kwargs = PyDict_New();
+    for (std::map<std::string, std::string>::const_iterator it = keywords.begin();
+         it != keywords.end(); ++it) {
+        PyDict_SetItemString(kwargs, it->first.c_str(), PyUnicode_FromString(it->second.c_str()));
+    }
+
+    PyObject* res =
+            PyObject_Call(detail::_interpreter::get().s_python_function_contour, plot_args, kwargs);
+
+    Py_DECREF(kwargs);
+    Py_DECREF(plot_args);
+    if (res)
+        Py_DECREF(res);
+
+    return res;
+}
+
+template<typename NumericX, typename NumericY, typename NumericU, typename NumericW>
+bool quiver(const std::vector<NumericX>& x, const std::vector<NumericY>& y, const std::vector<NumericU>& u, const std::vector<NumericW>& w, const std::map<std::string, std::string>& keywords = {})
+{
+    assert(x.size() == y.size() && x.size() == u.size() && u.size() == w.size());
+
+    detail::_interpreter::get();
+
+    PyObject* xarray = detail::get_array(x);
+    PyObject* yarray = detail::get_array(y);
+    PyObject* uarray = detail::get_array(u);
+    PyObject* warray = detail::get_array(w);
+
+    PyObject* plot_args = PyTuple_New(4);
+    PyTuple_SetItem(plot_args, 0, xarray);
+    PyTuple_SetItem(plot_args, 1, yarray);
+    PyTuple_SetItem(plot_args, 2, uarray);
+    PyTuple_SetItem(plot_args, 3, warray);
+
+    // construct keyword args
+    PyObject* kwargs = PyDict_New();
+    for(std::map<std::string, std::string>::const_iterator it = keywords.begin(); it != keywords.end(); ++it)
+    {
+        PyDict_SetItemString(kwargs, it->first.c_str(), PyUnicode_FromString(it->second.c_str()));
+    }
+
+    PyObject* res = PyObject_Call(
+            detail::_interpreter::get().s_python_function_quiver, plot_args, kwargs);
+
+    Py_DECREF(kwargs);
+    Py_DECREF(plot_args);
+    if (res)
+        Py_DECREF(res);
+
+    return res;
+}
+
 template<typename NumericX, typename NumericY>
 bool stem(const std::vector<NumericX>& x, const std::vector<NumericY>& y, const std::string& s = "")
 {
     assert(x.size() == y.size());
 
-    PyObject* xarray = get_array(x);
-    PyObject* yarray = get_array(y);
+    detail::_interpreter::get();
+
+    PyObject* xarray = detail::get_array(x);
+    PyObject* yarray = detail::get_array(y);
 
     PyObject* pystring = PyString_FromString(s.c_str());
 
@@ -617,8 +1203,10 @@
 {
     assert(x.size() == y.size());
 
-    PyObject* xarray = get_array(x);
-    PyObject* yarray = get_array(y);
+    detail::_interpreter::get();
+
+    PyObject* xarray = detail::get_array(x);
+    PyObject* yarray = detail::get_array(y);
 
     PyObject* pystring = PyString_FromString(s.c_str());
 
@@ -640,8 +1228,10 @@
 {
     assert(x.size() == y.size());
 
-    PyObject* xarray = get_array(x);
-    PyObject* yarray = get_array(y);
+    detail::_interpreter::get();
+
+    PyObject* xarray = detail::get_array(x);
+    PyObject* yarray = detail::get_array(y);
 
     PyObject* pystring = PyString_FromString(s.c_str());
 
@@ -663,8 +1253,10 @@
 {
     assert(x.size() == y.size());
 
-    PyObject* xarray = get_array(x);
-    PyObject* yarray = get_array(y);
+    detail::_interpreter::get();
+
+    PyObject* xarray = detail::get_array(x);
+    PyObject* yarray = detail::get_array(y);
 
     PyObject* pystring = PyString_FromString(s.c_str());
 
@@ -682,20 +1274,25 @@
 }
 
 template<typename NumericX, typename NumericY>
-bool errorbar(const std::vector<NumericX> &x, const std::vector<NumericY> &y, const std::vector<NumericX> &yerr, const std::string & /*s*/ = "")
+bool errorbar(const std::vector<NumericX> &x, const std::vector<NumericY> &y, const std::vector<NumericX> &yerr, const std::map<std::string, std::string> &keywords = {})
 {
     assert(x.size() == y.size());
 
-    PyObject* xarray = get_array(x);
-    PyObject* yarray = get_array(y);
-    PyObject* yerrarray = get_array(yerr);
+    detail::_interpreter::get();
 
-    PyObject *kwargs = PyDict_New();
+    PyObject* xarray = detail::get_array(x);
+    PyObject* yarray = detail::get_array(y);
+    PyObject* yerrarray = detail::get_array(yerr);
+
+    // construct keyword args
+    PyObject* kwargs = PyDict_New();
+    for(std::map<std::string, std::string>::const_iterator it = keywords.begin(); it != keywords.end(); ++it)
+    {
+        PyDict_SetItemString(kwargs, it->first.c_str(), PyString_FromString(it->second.c_str()));
+    }
 
     PyDict_SetItemString(kwargs, "yerr", yerrarray);
 
-    //PyObject *pystring = PyString_FromString(s.c_str());
-
     PyObject *plot_args = PyTuple_New(2);
     PyTuple_SetItem(plot_args, 0, xarray);
     PyTuple_SetItem(plot_args, 1, yarray);
@@ -716,10 +1313,12 @@
 template<typename Numeric>
 bool named_plot(const std::string& name, const std::vector<Numeric>& y, const std::string& format = "")
 {
+    detail::_interpreter::get();
+
     PyObject* kwargs = PyDict_New();
     PyDict_SetItemString(kwargs, "label", PyString_FromString(name.c_str()));
 
-    PyObject* yarray = get_array(y);
+    PyObject* yarray = detail::get_array(y);
 
     PyObject* pystring = PyString_FromString(format.c_str());
 
@@ -740,11 +1339,13 @@
 template<typename Numeric>
 bool named_plot(const std::string& name, const std::vector<Numeric>& x, const std::vector<Numeric>& y, const std::string& format = "")
 {
+    detail::_interpreter::get();
+
     PyObject* kwargs = PyDict_New();
     PyDict_SetItemString(kwargs, "label", PyString_FromString(name.c_str()));
 
-    PyObject* xarray = get_array(x);
-    PyObject* yarray = get_array(y);
+    PyObject* xarray = detail::get_array(x);
+    PyObject* yarray = detail::get_array(y);
 
     PyObject* pystring = PyString_FromString(format.c_str());
 
@@ -765,11 +1366,13 @@
 template<typename Numeric>
 bool named_semilogx(const std::string& name, const std::vector<Numeric>& x, const std::vector<Numeric>& y, const std::string& format = "")
 {
+    detail::_interpreter::get();
+
     PyObject* kwargs = PyDict_New();
     PyDict_SetItemString(kwargs, "label", PyString_FromString(name.c_str()));
 
-    PyObject* xarray = get_array(x);
-    PyObject* yarray = get_array(y);
+    PyObject* xarray = detail::get_array(x);
+    PyObject* yarray = detail::get_array(y);
 
     PyObject* pystring = PyString_FromString(format.c_str());
 
@@ -790,11 +1393,13 @@
 template<typename Numeric>
 bool named_semilogy(const std::string& name, const std::vector<Numeric>& x, const std::vector<Numeric>& y, const std::string& format = "")
 {
+    detail::_interpreter::get();
+
     PyObject* kwargs = PyDict_New();
     PyDict_SetItemString(kwargs, "label", PyString_FromString(name.c_str()));
 
-    PyObject* xarray = get_array(x);
-    PyObject* yarray = get_array(y);
+    PyObject* xarray = detail::get_array(x);
+    PyObject* yarray = detail::get_array(y);
 
     PyObject* pystring = PyString_FromString(format.c_str());
 
@@ -815,11 +1420,13 @@
 template<typename Numeric>
 bool named_loglog(const std::string& name, const std::vector<Numeric>& x, const std::vector<Numeric>& y, const std::string& format = "")
 {
+    detail::_interpreter::get();
+
     PyObject* kwargs = PyDict_New();
     PyDict_SetItemString(kwargs, "label", PyString_FromString(name.c_str()));
 
-    PyObject* xarray = get_array(x);
-    PyObject* yarray = get_array(y);
+    PyObject* xarray = detail::get_array(x);
+    PyObject* yarray = detail::get_array(y);
 
     PyObject* pystring = PyString_FromString(format.c_str());
 
@@ -827,7 +1434,6 @@
     PyTuple_SetItem(plot_args, 0, xarray);
     PyTuple_SetItem(plot_args, 1, yarray);
     PyTuple_SetItem(plot_args, 2, pystring);
-
     PyObject* res = PyObject_Call(detail::_interpreter::get().s_python_function_loglog, plot_args, kwargs);
 
     Py_DECREF(kwargs);
@@ -846,6 +1452,14 @@
 }
 
 template<typename Numeric>
+bool plot(const std::vector<Numeric>& y, const std::map<std::string, std::string>& keywords)
+{
+    std::vector<Numeric> x(y.size());
+    for(size_t i=0; i<x.size(); ++i) x.at(i) = i;
+    return plot(x,y,keywords);
+}
+
+template<typename Numeric>
 bool stem(const std::vector<Numeric>& y, const std::string& format = "")
 {
     std::vector<Numeric> x(y.size());
@@ -853,25 +1467,150 @@
     return stem(x, y, format);
 }
 
-inline void figure()
+template<typename Numeric>
+void text(Numeric x, Numeric y, const std::string& s = "")
 {
-    PyObject* res = PyObject_CallObject(detail::_interpreter::get().s_python_function_figure, detail::_interpreter::get().s_python_empty_tuple);
+    detail::_interpreter::get();
+
+    PyObject* args = PyTuple_New(3);
+    PyTuple_SetItem(args, 0, PyFloat_FromDouble(x));
+    PyTuple_SetItem(args, 1, PyFloat_FromDouble(y));
+    PyTuple_SetItem(args, 2, PyString_FromString(s.c_str()));
+
+    PyObject* res = PyObject_CallObject(detail::_interpreter::get().s_python_function_text, args);
+    if(!res) throw std::runtime_error("Call to text() failed.");
+
+    Py_DECREF(args);
+    Py_DECREF(res);
+}
+
+inline void colorbar(PyObject* mappable = NULL, const std::map<std::string, float>& keywords = {})
+{
+    if (mappable == NULL)
+        throw std::runtime_error("Must call colorbar with PyObject* returned from an image, contour, surface, etc.");
+
+    detail::_interpreter::get();
+
+    PyObject* args = PyTuple_New(1);
+    PyTuple_SetItem(args, 0, mappable);
+
+    PyObject* kwargs = PyDict_New();
+    for(std::map<std::string, float>::const_iterator it = keywords.begin(); it != keywords.end(); ++it)
+    {
+        PyDict_SetItemString(kwargs, it->first.c_str(), PyFloat_FromDouble(it->second));
+    }
+
+    PyObject* res = PyObject_Call(detail::_interpreter::get().s_python_function_colorbar, args, kwargs);
+    if(!res) throw std::runtime_error("Call to colorbar() failed.");
+
+    Py_DECREF(args);
+    Py_DECREF(kwargs);
+    Py_DECREF(res);
+}
+
+
+inline long figure(long number = -1)
+{
+    detail::_interpreter::get();
+
+    PyObject *res;
+    if (number == -1)
+        res = PyObject_CallObject(detail::_interpreter::get().s_python_function_figure, detail::_interpreter::get().s_python_empty_tuple);
+    else {
+        assert(number > 0);
+
+        // Make sure interpreter is initialised
+        detail::_interpreter::get();
+
+        PyObject *args = PyTuple_New(1);
+        PyTuple_SetItem(args, 0, PyLong_FromLong(number));
+        res = PyObject_CallObject(detail::_interpreter::get().s_python_function_figure, args);
+        Py_DECREF(args);
+    }
+
     if(!res) throw std::runtime_error("Call to figure() failed.");
 
+    PyObject* num = PyObject_GetAttrString(res, "number");
+    if (!num) throw std::runtime_error("Could not get number attribute of figure object");
+    const long figureNumber = PyLong_AsLong(num);
+
+    Py_DECREF(num);
+    Py_DECREF(res);
+
+    return figureNumber;
+}
+
+inline bool fignum_exists(long number)
+{
+    detail::_interpreter::get();
+
+    PyObject *args = PyTuple_New(1);
+    PyTuple_SetItem(args, 0, PyLong_FromLong(number));
+    PyObject *res = PyObject_CallObject(detail::_interpreter::get().s_python_function_fignum_exists, args);
+    if(!res) throw std::runtime_error("Call to fignum_exists() failed.");
+
+    bool ret = PyObject_IsTrue(res);
+    Py_DECREF(res);
+    Py_DECREF(args);
+
+    return ret;
+}
+
+inline void figure_size(size_t w, size_t h)
+{
+    detail::_interpreter::get();
+
+    const size_t dpi = 100;
+    PyObject* size = PyTuple_New(2);
+    PyTuple_SetItem(size, 0, PyFloat_FromDouble((double)w / dpi));
+    PyTuple_SetItem(size, 1, PyFloat_FromDouble((double)h / dpi));
+
+    PyObject* kwargs = PyDict_New();
+    PyDict_SetItemString(kwargs, "figsize", size);
+    PyDict_SetItemString(kwargs, "dpi", PyLong_FromSize_t(dpi));
+
+    PyObject* res = PyObject_Call(detail::_interpreter::get().s_python_function_figure,
+            detail::_interpreter::get().s_python_empty_tuple, kwargs);
+
+    Py_DECREF(kwargs);
+
+    if(!res) throw std::runtime_error("Call to figure_size() failed.");
     Py_DECREF(res);
 }
 
 inline void legend()
 {
+    detail::_interpreter::get();
+
     PyObject* res = PyObject_CallObject(detail::_interpreter::get().s_python_function_legend, detail::_interpreter::get().s_python_empty_tuple);
     if(!res) throw std::runtime_error("Call to legend() failed.");
 
     Py_DECREF(res);
 }
 
+inline void legend(const std::map<std::string, std::string>& keywords)
+{
+  detail::_interpreter::get();
+
+  // construct keyword args
+  PyObject* kwargs = PyDict_New();
+  for(std::map<std::string, std::string>::const_iterator it = keywords.begin(); it != keywords.end(); ++it)
+  {
+    PyDict_SetItemString(kwargs, it->first.c_str(), PyString_FromString(it->second.c_str()));
+  }
+
+  PyObject* res = PyObject_Call(detail::_interpreter::get().s_python_function_legend, detail::_interpreter::get().s_python_empty_tuple, kwargs);
+  if(!res) throw std::runtime_error("Call to legend() failed.");
+
+  Py_DECREF(kwargs);
+  Py_DECREF(res);  
+}
+
 template<typename Numeric>
 void ylim(Numeric left, Numeric right)
 {
+    detail::_interpreter::get();
+
     PyObject* list = PyList_New(2);
     PyList_SetItem(list, 0, PyFloat_FromDouble(left));
     PyList_SetItem(list, 1, PyFloat_FromDouble(right));
@@ -889,6 +1628,8 @@
 template<typename Numeric>
 void xlim(Numeric left, Numeric right)
 {
+    detail::_interpreter::get();
+
     PyObject* list = PyList_New(2);
     PyList_SetItem(list, 0, PyFloat_FromDouble(left));
     PyList_SetItem(list, 1, PyFloat_FromDouble(right));
@@ -906,6 +1647,8 @@
 
 inline double* xlim()
 {
+    detail::_interpreter::get();
+
     PyObject* args = PyTuple_New(0);
     PyObject* res = PyObject_CallObject(detail::_interpreter::get().s_python_function_xlim, args);
     PyObject* left = PyTuple_GetItem(res,0);
@@ -924,6 +1667,8 @@
 
 inline double* ylim()
 {
+    detail::_interpreter::get();
+
     PyObject* args = PyTuple_New(0);
     PyObject* res = PyObject_CallObject(detail::_interpreter::get().s_python_function_ylim, args);
     PyObject* left = PyTuple_GetItem(res,0);
@@ -939,8 +1684,166 @@
     return arr;
 }
 
+template<typename Numeric>
+inline void xticks(const std::vector<Numeric> &ticks, const std::vector<std::string> &labels = {}, const std::map<std::string, std::string>& keywords = {})
+{
+    assert(labels.size() == 0 || ticks.size() == labels.size());
+
+    detail::_interpreter::get();
+
+    // using numpy array
+    PyObject* ticksarray = detail::get_array(ticks);
+
+    PyObject* args;
+    if(labels.size() == 0) {
+        // construct positional args
+        args = PyTuple_New(1);
+        PyTuple_SetItem(args, 0, ticksarray);
+    } else {
+        // make tuple of tick labels
+        PyObject* labelstuple = PyTuple_New(labels.size());
+        for (size_t i = 0; i < labels.size(); i++)
+            PyTuple_SetItem(labelstuple, i, PyUnicode_FromString(labels[i].c_str()));
+
+        // construct positional args
+        args = PyTuple_New(2);
+        PyTuple_SetItem(args, 0, ticksarray);
+        PyTuple_SetItem(args, 1, labelstuple);
+    }
+
+    // construct keyword args
+    PyObject* kwargs = PyDict_New();
+    for(std::map<std::string, std::string>::const_iterator it = keywords.begin(); it != keywords.end(); ++it)
+    {
+        PyDict_SetItemString(kwargs, it->first.c_str(), PyString_FromString(it->second.c_str()));
+    }
+
+    PyObject* res = PyObject_Call(detail::_interpreter::get().s_python_function_xticks, args, kwargs);
+
+    Py_DECREF(args);
+    Py_DECREF(kwargs);
+    if(!res) throw std::runtime_error("Call to xticks() failed");
+
+    Py_DECREF(res);
+}
+
+template<typename Numeric>
+inline void xticks(const std::vector<Numeric> &ticks, const std::map<std::string, std::string>& keywords)
+{
+    xticks(ticks, {}, keywords);
+}
+
+template<typename Numeric>
+inline void yticks(const std::vector<Numeric> &ticks, const std::vector<std::string> &labels = {}, const std::map<std::string, std::string>& keywords = {})
+{
+    assert(labels.size() == 0 || ticks.size() == labels.size());
+
+    detail::_interpreter::get();
+
+    // using numpy array
+    PyObject* ticksarray = detail::get_array(ticks);
+
+    PyObject* args;
+    if(labels.size() == 0) {
+        // construct positional args
+        args = PyTuple_New(1);
+        PyTuple_SetItem(args, 0, ticksarray);
+    } else {
+        // make tuple of tick labels
+        PyObject* labelstuple = PyTuple_New(labels.size());
+        for (size_t i = 0; i < labels.size(); i++)
+            PyTuple_SetItem(labelstuple, i, PyUnicode_FromString(labels[i].c_str()));
+
+        // construct positional args
+        args = PyTuple_New(2);
+        PyTuple_SetItem(args, 0, ticksarray);
+        PyTuple_SetItem(args, 1, labelstuple);
+    }
+
+    // construct keyword args
+    PyObject* kwargs = PyDict_New();
+    for(std::map<std::string, std::string>::const_iterator it = keywords.begin(); it != keywords.end(); ++it)
+    {
+        PyDict_SetItemString(kwargs, it->first.c_str(), PyString_FromString(it->second.c_str()));
+    }
+
+    PyObject* res = PyObject_Call(detail::_interpreter::get().s_python_function_yticks, args, kwargs);
+
+    Py_DECREF(args);
+    Py_DECREF(kwargs);
+    if(!res) throw std::runtime_error("Call to yticks() failed");
+
+    Py_DECREF(res);
+}
+
+template<typename Numeric>
+inline void yticks(const std::vector<Numeric> &ticks, const std::map<std::string, std::string>& keywords)
+{
+    yticks(ticks, {}, keywords);
+}
+
+template <typename Numeric> inline void margins(Numeric margin)
+{
+    // construct positional args
+    PyObject* args = PyTuple_New(1);
+    PyTuple_SetItem(args, 0, PyFloat_FromDouble(margin));
+
+    PyObject* res =
+            PyObject_CallObject(detail::_interpreter::get().s_python_function_margins, args);
+    if (!res)
+        throw std::runtime_error("Call to margins() failed.");
+
+    Py_DECREF(args);
+    Py_DECREF(res);
+}
+
+template <typename Numeric> inline void margins(Numeric margin_x, Numeric margin_y)
+{
+    // construct positional args
+    PyObject* args = PyTuple_New(2);
+    PyTuple_SetItem(args, 0, PyFloat_FromDouble(margin_x));
+    PyTuple_SetItem(args, 1, PyFloat_FromDouble(margin_y));
+
+    PyObject* res =
+            PyObject_CallObject(detail::_interpreter::get().s_python_function_margins, args);
+    if (!res)
+        throw std::runtime_error("Call to margins() failed.");
+
+    Py_DECREF(args);
+    Py_DECREF(res);
+}
+
+
+inline void tick_params(const std::map<std::string, std::string>& keywords, const std::string axis = "both")
+{
+  detail::_interpreter::get();
+
+  // construct positional args
+  PyObject* args;
+  args = PyTuple_New(1);
+  PyTuple_SetItem(args, 0, PyString_FromString(axis.c_str()));
+
+  // construct keyword args
+  PyObject* kwargs = PyDict_New();
+  for (std::map<std::string, std::string>::const_iterator it = keywords.begin(); it != keywords.end(); ++it)
+  {
+    PyDict_SetItemString(kwargs, it->first.c_str(), PyString_FromString(it->second.c_str()));
+  }
+
+
+  PyObject* res = PyObject_Call(detail::_interpreter::get().s_python_function_tick_params, args, kwargs);
+
+  Py_DECREF(args);
+  Py_DECREF(kwargs);
+  if (!res) throw std::runtime_error("Call to tick_params() failed");
+
+  Py_DECREF(res);
+}
+
 inline void subplot(long nrows, long ncols, long plot_number)
 {
+    detail::_interpreter::get();
+    
     // construct positional args
     PyObject* args = PyTuple_New(3);
     PyTuple_SetItem(args, 0, PyFloat_FromDouble(nrows));
@@ -954,21 +1857,79 @@
     Py_DECREF(res);
 }
 
-inline void title(const std::string &titlestr)
+inline void subplot2grid(long nrows, long ncols, long rowid=0, long colid=0, long rowspan=1, long colspan=1)
 {
+    detail::_interpreter::get();
+
+    PyObject* shape = PyTuple_New(2);
+    PyTuple_SetItem(shape, 0, PyLong_FromLong(nrows));
+    PyTuple_SetItem(shape, 1, PyLong_FromLong(ncols));
+
+    PyObject* loc = PyTuple_New(2);
+    PyTuple_SetItem(loc, 0, PyLong_FromLong(rowid));
+    PyTuple_SetItem(loc, 1, PyLong_FromLong(colid));
+
+    PyObject* args = PyTuple_New(4);
+    PyTuple_SetItem(args, 0, shape);
+    PyTuple_SetItem(args, 1, loc);
+    PyTuple_SetItem(args, 2, PyLong_FromLong(rowspan));
+    PyTuple_SetItem(args, 3, PyLong_FromLong(colspan));
+
+    PyObject* res = PyObject_CallObject(detail::_interpreter::get().s_python_function_subplot2grid, args);
+    if(!res) throw std::runtime_error("Call to subplot2grid() failed.");
+
+    Py_DECREF(shape);
+    Py_DECREF(loc);
+    Py_DECREF(args);
+    Py_DECREF(res);
+}
+
+inline void title(const std::string &titlestr, const std::map<std::string, std::string> &keywords = {})
+{
+    detail::_interpreter::get();
+
     PyObject* pytitlestr = PyString_FromString(titlestr.c_str());
     PyObject* args = PyTuple_New(1);
     PyTuple_SetItem(args, 0, pytitlestr);
 
-    PyObject* res = PyObject_CallObject(detail::_interpreter::get().s_python_function_title, args);
+    PyObject* kwargs = PyDict_New();
+    for (auto it = keywords.begin(); it != keywords.end(); ++it) {
+        PyDict_SetItemString(kwargs, it->first.c_str(), PyUnicode_FromString(it->second.c_str()));
+    }
+
+    PyObject* res = PyObject_Call(detail::_interpreter::get().s_python_function_title, args, kwargs);
     if(!res) throw std::runtime_error("Call to title() failed.");
 
     Py_DECREF(args);
+    Py_DECREF(kwargs);
+    Py_DECREF(res);
+}
+
+inline void suptitle(const std::string &suptitlestr, const std::map<std::string, std::string> &keywords = {})
+{
+    detail::_interpreter::get();
+    
+    PyObject* pysuptitlestr = PyString_FromString(suptitlestr.c_str());
+    PyObject* args = PyTuple_New(1);
+    PyTuple_SetItem(args, 0, pysuptitlestr);
+
+    PyObject* kwargs = PyDict_New();
+    for (auto it = keywords.begin(); it != keywords.end(); ++it) {
+        PyDict_SetItemString(kwargs, it->first.c_str(), PyUnicode_FromString(it->second.c_str()));
+    }
+
+    PyObject* res = PyObject_Call(detail::_interpreter::get().s_python_function_suptitle, args, kwargs);
+    if(!res) throw std::runtime_error("Call to suptitle() failed.");
+
+    Py_DECREF(args);
+    Py_DECREF(kwargs);
     Py_DECREF(res);
 }
 
 inline void axis(const std::string &axisstr)
 {
+    detail::_interpreter::get();
+
     PyObject* str = PyString_FromString(axisstr.c_str());
     PyObject* args = PyTuple_New(1);
     PyTuple_SetItem(args, 0, str);
@@ -980,34 +1941,155 @@
     Py_DECREF(res);
 }
 
-inline void xlabel(const std::string &str)
+inline void axvline(double x, double ymin = 0., double ymax = 1., const std::map<std::string, std::string>& keywords = std::map<std::string, std::string>())
 {
+    detail::_interpreter::get();
+
+    // construct positional args
+    PyObject* args = PyTuple_New(3);
+    PyTuple_SetItem(args, 0, PyFloat_FromDouble(x));
+    PyTuple_SetItem(args, 1, PyFloat_FromDouble(ymin));
+    PyTuple_SetItem(args, 2, PyFloat_FromDouble(ymax));
+
+    // construct keyword args
+    PyObject* kwargs = PyDict_New();
+    for(std::map<std::string, std::string>::const_iterator it = keywords.begin(); it != keywords.end(); ++it)
+    {
+        PyDict_SetItemString(kwargs, it->first.c_str(), PyString_FromString(it->second.c_str()));
+    }
+
+    PyObject* res = PyObject_Call(detail::_interpreter::get().s_python_function_axvline, args, kwargs);
+
+    Py_DECREF(args);
+    Py_DECREF(kwargs);
+
+    if(res) Py_DECREF(res);
+}
+
+inline void axvspan(double xmin, double xmax, double ymin = 0., double ymax = 1., const std::map<std::string, std::string>& keywords = std::map<std::string, std::string>())
+{
+    // construct positional args
+    PyObject* args = PyTuple_New(4);
+    PyTuple_SetItem(args, 0, PyFloat_FromDouble(xmin));
+    PyTuple_SetItem(args, 1, PyFloat_FromDouble(xmax));
+    PyTuple_SetItem(args, 2, PyFloat_FromDouble(ymin));
+    PyTuple_SetItem(args, 3, PyFloat_FromDouble(ymax));
+
+    // construct keyword args
+    PyObject* kwargs = PyDict_New();
+    for(std::map<std::string, std::string>::const_iterator it = keywords.begin(); it != keywords.end(); ++it)
+    {
+	if (it->first == "linewidth" || it->first == "alpha")
+    	    PyDict_SetItemString(kwargs, it->first.c_str(), PyFloat_FromDouble(std::stod(it->second)));
+  	else
+    	    PyDict_SetItemString(kwargs, it->first.c_str(), PyString_FromString(it->second.c_str()));
+    }
+
+    PyObject* res = PyObject_Call(detail::_interpreter::get().s_python_function_axvspan, args, kwargs);
+    Py_DECREF(args);
+    Py_DECREF(kwargs);
+
+    if(res) Py_DECREF(res);
+}
+
+inline void xlabel(const std::string &str, const std::map<std::string, std::string> &keywords = {})
+{
+    detail::_interpreter::get();
+
     PyObject* pystr = PyString_FromString(str.c_str());
     PyObject* args = PyTuple_New(1);
     PyTuple_SetItem(args, 0, pystr);
 
-    PyObject* res = PyObject_CallObject(detail::_interpreter::get().s_python_function_xlabel, args);
+    PyObject* kwargs = PyDict_New();
+    for (auto it = keywords.begin(); it != keywords.end(); ++it) {
+        PyDict_SetItemString(kwargs, it->first.c_str(), PyUnicode_FromString(it->second.c_str()));
+    }
+
+    PyObject* res = PyObject_Call(detail::_interpreter::get().s_python_function_xlabel, args, kwargs);
     if(!res) throw std::runtime_error("Call to xlabel() failed.");
 
     Py_DECREF(args);
+    Py_DECREF(kwargs);
     Py_DECREF(res);
 }
 
-inline void ylabel(const std::string &str)
+inline void ylabel(const std::string &str, const std::map<std::string, std::string>& keywords = {})
 {
+    detail::_interpreter::get();
+
     PyObject* pystr = PyString_FromString(str.c_str());
     PyObject* args = PyTuple_New(1);
     PyTuple_SetItem(args, 0, pystr);
 
-    PyObject* res = PyObject_CallObject(detail::_interpreter::get().s_python_function_ylabel, args);
+    PyObject* kwargs = PyDict_New();
+    for (auto it = keywords.begin(); it != keywords.end(); ++it) {
+        PyDict_SetItemString(kwargs, it->first.c_str(), PyUnicode_FromString(it->second.c_str()));
+    }
+
+    PyObject* res = PyObject_Call(detail::_interpreter::get().s_python_function_ylabel, args, kwargs);
     if(!res) throw std::runtime_error("Call to ylabel() failed.");
 
     Py_DECREF(args);
+    Py_DECREF(kwargs);
     Py_DECREF(res);
 }
 
+inline void set_zlabel(const std::string &str, const std::map<std::string, std::string>& keywords = {})
+{
+    detail::_interpreter::get();
+
+    // Same as with plot_surface: We lazily load the modules here the first time 
+    // this function is called because I'm not sure that we can assume "matplotlib 
+    // installed" implies "mpl_toolkits installed" on all platforms, and we don't 
+    // want to require it for people who don't need 3d plots.
+    static PyObject *mpl_toolkitsmod = nullptr, *axis3dmod = nullptr;
+    if (!mpl_toolkitsmod) {
+        PyObject* mpl_toolkits = PyString_FromString("mpl_toolkits");
+        PyObject* axis3d = PyString_FromString("mpl_toolkits.mplot3d");
+        if (!mpl_toolkits || !axis3d) { throw std::runtime_error("couldnt create string"); }
+
+        mpl_toolkitsmod = PyImport_Import(mpl_toolkits);
+        Py_DECREF(mpl_toolkits);
+        if (!mpl_toolkitsmod) { throw std::runtime_error("Error loading module mpl_toolkits!"); }
+
+        axis3dmod = PyImport_Import(axis3d);
+        Py_DECREF(axis3d);
+        if (!axis3dmod) { throw std::runtime_error("Error loading module mpl_toolkits.mplot3d!"); }
+    }
+
+    PyObject* pystr = PyString_FromString(str.c_str());
+    PyObject* args = PyTuple_New(1);
+    PyTuple_SetItem(args, 0, pystr);
+
+    PyObject* kwargs = PyDict_New();
+    for (auto it = keywords.begin(); it != keywords.end(); ++it) {
+        PyDict_SetItemString(kwargs, it->first.c_str(), PyUnicode_FromString(it->second.c_str()));
+    }
+
+    PyObject *ax =
+    PyObject_CallObject(detail::_interpreter::get().s_python_function_gca,
+      detail::_interpreter::get().s_python_empty_tuple);
+    if (!ax) throw std::runtime_error("Call to gca() failed.");
+    Py_INCREF(ax);
+
+    PyObject *zlabel = PyObject_GetAttrString(ax, "set_zlabel");
+    if (!zlabel) throw std::runtime_error("Attribute set_zlabel not found.");
+    Py_INCREF(zlabel);
+
+    PyObject *res = PyObject_Call(zlabel, args, kwargs);
+    if (!res) throw std::runtime_error("Call to set_zlabel() failed.");
+    Py_DECREF(zlabel);
+
+    Py_DECREF(ax);
+    Py_DECREF(args);
+    Py_DECREF(kwargs);
+    if (res) Py_DECREF(res);
+}
+
 inline void grid(bool flag)
 {
+    detail::_interpreter::get();
+
     PyObject* pyflag = flag ? Py_True : Py_False;
     Py_INCREF(pyflag);
 
@@ -1023,6 +2105,8 @@
 
 inline void show(const bool block = true)
 {
+    detail::_interpreter::get();
+
     PyObject* res;
     if(block)
     {
@@ -1035,7 +2119,7 @@
         PyObject *kwargs = PyDict_New();
         PyDict_SetItemString(kwargs, "block", Py_False);
         res = PyObject_Call( detail::_interpreter::get().s_python_function_show, detail::_interpreter::get().s_python_empty_tuple, kwargs);
-	Py_DECREF(kwargs);
+       Py_DECREF(kwargs);
     }
 
 
@@ -1046,6 +2130,8 @@
 
 inline void close()
 {
+    detail::_interpreter::get();
+
     PyObject* res = PyObject_CallObject(
             detail::_interpreter::get().s_python_function_close,
             detail::_interpreter::get().s_python_empty_tuple);
@@ -1056,6 +2142,8 @@
 }
 
 inline void xkcd() {
+    detail::_interpreter::get();
+
     PyObject* res;
     PyObject *kwargs = PyDict_New();
 
@@ -1072,6 +2160,8 @@
 
 inline void draw()
 {
+    detail::_interpreter::get();
+
     PyObject* res = PyObject_CallObject(
         detail::_interpreter::get().s_python_function_draw,
         detail::_interpreter::get().s_python_empty_tuple);
@@ -1084,6 +2174,8 @@
 template<typename Numeric>
 inline void pause(Numeric interval)
 {
+    detail::_interpreter::get();
+
     PyObject* args = PyTuple_New(1);
     PyTuple_SetItem(args, 0, PyFloat_FromDouble(interval));
 
@@ -1096,6 +2188,8 @@
 
 inline void save(const std::string& filename)
 {
+    detail::_interpreter::get();
+
     PyObject* pyfilename = PyString_FromString(filename.c_str());
 
     PyObject* args = PyTuple_New(1);
@@ -1109,6 +2203,8 @@
 }
 
 inline void clf() {
+    detail::_interpreter::get();
+
     PyObject *res = PyObject_CallObject(
         detail::_interpreter::get().s_python_function_clf,
         detail::_interpreter::get().s_python_empty_tuple);
@@ -1118,7 +2214,21 @@
     Py_DECREF(res);
 }
 
-    inline void ion() {
+inline void cla() {
+    detail::_interpreter::get();
+
+    PyObject* res = PyObject_CallObject(detail::_interpreter::get().s_python_function_cla,
+                                        detail::_interpreter::get().s_python_empty_tuple);
+
+    if (!res)
+        throw std::runtime_error("Call to cla() failed.");
+
+    Py_DECREF(res);
+}
+
+inline void ion() {
+    detail::_interpreter::get();
+
     PyObject *res = PyObject_CallObject(
         detail::_interpreter::get().s_python_function_ion,
         detail::_interpreter::get().s_python_empty_tuple);
@@ -1128,8 +2238,46 @@
     Py_DECREF(res);
 }
 
+inline std::vector<std::array<double, 2>> ginput(const int numClicks = 1, const std::map<std::string, std::string>& keywords = {})
+{
+    detail::_interpreter::get();
+
+    PyObject *args = PyTuple_New(1);
+    PyTuple_SetItem(args, 0, PyLong_FromLong(numClicks));
+
+    // construct keyword args
+    PyObject* kwargs = PyDict_New();
+    for(std::map<std::string, std::string>::const_iterator it = keywords.begin(); it != keywords.end(); ++it)
+    {
+        PyDict_SetItemString(kwargs, it->first.c_str(), PyUnicode_FromString(it->second.c_str()));
+    }
+
+    PyObject* res = PyObject_Call(
+        detail::_interpreter::get().s_python_function_ginput, args, kwargs);
+
+    Py_DECREF(kwargs);
+    Py_DECREF(args);
+    if (!res) throw std::runtime_error("Call to ginput() failed.");
+
+    const size_t len = PyList_Size(res);
+    std::vector<std::array<double, 2>> out;
+    out.reserve(len);
+    for (size_t i = 0; i < len; i++) {
+        PyObject *current = PyList_GetItem(res, i);
+        std::array<double, 2> position;
+        position[0] = PyFloat_AsDouble(PyTuple_GetItem(current, 0));
+        position[1] = PyFloat_AsDouble(PyTuple_GetItem(current, 1));
+        out.push_back(position);
+    }
+    Py_DECREF(res);
+
+    return out;
+}
+
 // Actually, is there any reason not to call this automatically for every plot?
 inline void tight_layout() {
+    detail::_interpreter::get();
+
     PyObject *res = PyObject_CallObject(
         detail::_interpreter::get().s_python_function_tight_layout,
         detail::_interpreter::get().s_python_empty_tuple);
@@ -1139,8 +2287,7 @@
     Py_DECREF(res);
 }
 
-#if __cplusplus > 199711L || _MSC_VER > 1800
-// C++11-exclusive content starts here (variadic plot() and initializer list support)
+// Support for variadic plot() and initializer lists:
 
 namespace detail {
 
@@ -1269,6 +2416,106 @@
     return plot<double>(x,y,keywords);
 }
 
-#endif
+/*
+ * This class allows dynamic plots, ie changing the plotted data without clearing and re-plotting
+ */
+class Plot
+{
+public:
+    // default initialization with plot label, some data and format
+    template<typename Numeric>
+    Plot(const std::string& name, const std::vector<Numeric>& x, const std::vector<Numeric>& y, const std::string& format = "") {
+        detail::_interpreter::get();
+
+        assert(x.size() == y.size());
+
+        PyObject* kwargs = PyDict_New();
+        if(name != "")
+            PyDict_SetItemString(kwargs, "label", PyString_FromString(name.c_str()));
+
+        PyObject* xarray = detail::get_array(x);
+        PyObject* yarray = detail::get_array(y);
+
+        PyObject* pystring = PyString_FromString(format.c_str());
+
+        PyObject* plot_args = PyTuple_New(3);
+        PyTuple_SetItem(plot_args, 0, xarray);
+        PyTuple_SetItem(plot_args, 1, yarray);
+        PyTuple_SetItem(plot_args, 2, pystring);
+
+        PyObject* res = PyObject_Call(detail::_interpreter::get().s_python_function_plot, plot_args, kwargs);
+
+        Py_DECREF(kwargs);
+        Py_DECREF(plot_args);
+
+        if(res)
+        {
+            line= PyList_GetItem(res, 0);
+
+            if(line)
+                set_data_fct = PyObject_GetAttrString(line,"set_data");
+            else
+                Py_DECREF(line);
+            Py_DECREF(res);
+        }
+    }
+
+    // shorter initialization with name or format only
+    // basically calls line, = plot([], [])
+    Plot(const std::string& name = "", const std::string& format = "")
+        : Plot(name, std::vector<double>(), std::vector<double>(), format) {}
+
+    template<typename Numeric>
+    bool update(const std::vector<Numeric>& x, const std::vector<Numeric>& y) {
+        assert(x.size() == y.size());
+        if(set_data_fct)
+        {
+            PyObject* xarray = detail::get_array(x);
+            PyObject* yarray = detail::get_array(y);
+
+            PyObject* plot_args = PyTuple_New(2);
+            PyTuple_SetItem(plot_args, 0, xarray);
+            PyTuple_SetItem(plot_args, 1, yarray);
+
+            PyObject* res = PyObject_CallObject(set_data_fct, plot_args);
+            if (res) Py_DECREF(res);
+            return res;
+        }
+        return false;
+    }
+
+    // clears the plot but keep it available
+    bool clear() {
+        return update(std::vector<double>(), std::vector<double>());
+    }
+
+    // definitely remove this line
+    void remove() {
+        if(line)
+        {
+            auto remove_fct = PyObject_GetAttrString(line,"remove");
+            PyObject* args = PyTuple_New(0);
+            PyObject* res = PyObject_CallObject(remove_fct, args);
+            if (res) Py_DECREF(res);
+        }
+        decref();
+    }
+
+    ~Plot() {
+        decref();
+    }
+private:
+
+    void decref() {
+        if(line)
+            Py_DECREF(line);
+        if(set_data_fct)
+            Py_DECREF(set_data_fct);
+    }
+
+
+    PyObject* line = nullptr;
+    PyObject* set_data_fct = nullptr;
+};
 
 } // end namespace matplotlibcpp