diff --git a/blas/common.h b/blas/common.h
index 2bf642c..61d8344 100644
--- a/blas/common.h
+++ b/blas/common.h
@@ -1,7 +1,7 @@
 // This file is part of Eigen, a lightweight C++ template library
 // for linear algebra.
 //
-// Copyright (C) 2009-2010 Gael Guennebaud <gael.guennebaud@inria.fr>
+// Copyright (C) 2009-2015 Gael Guennebaud <gael.guennebaud@inria.fr>
 //
 // This Source Code Form is subject to the terms of the Mozilla
 // Public License v. 2.0. If a copy of the MPL was not distributed
@@ -10,18 +10,16 @@
 #ifndef EIGEN_BLAS_COMMON_H
 #define EIGEN_BLAS_COMMON_H
 
-#include <Eigen/Core>
-#include <Eigen/Jacobi>
+#include "../Eigen/Core"
+#include "../Eigen/Jacobi"
 
-#include <iostream>
 #include <complex>
 
 #ifndef SCALAR
 #error the token SCALAR must be defined to compile this file
 #endif
 
-#include <Eigen/src/misc/blas.h>
-
+#include "../Eigen/src/misc/blas.h"
 
 #define NOTR    0
 #define TR      1
@@ -95,6 +93,7 @@
 
 typedef Matrix<Scalar,Dynamic,Dynamic,ColMajor> PlainMatrixType;
 typedef Map<Matrix<Scalar,Dynamic,Dynamic,ColMajor>, 0, OuterStride<> > MatrixType;
+typedef Map<const Matrix<Scalar,Dynamic,Dynamic,ColMajor>, 0, OuterStride<> > ConstMatrixType;
 typedef Map<Matrix<Scalar,Dynamic,1>, 0, InnerStride<Dynamic> > StridedVectorType;
 typedef Map<Matrix<Scalar,Dynamic,1> > CompactVectorType;
 
@@ -106,26 +105,45 @@
 }
 
 template<typename T>
-Map<Matrix<T,Dynamic,1>, 0, InnerStride<Dynamic> > vector(T* data, int size, int incr)
+Map<const Matrix<T,Dynamic,Dynamic,ColMajor>, 0, OuterStride<> >
+matrix(const T* data, int rows, int cols, int stride)
+{
+  return Map<const Matrix<T,Dynamic,Dynamic,ColMajor>, 0, OuterStride<> >(data, rows, cols, OuterStride<>(stride));
+}
+
+template<typename T>
+Map<Matrix<T,Dynamic,1>, 0, InnerStride<Dynamic> > make_vector(T* data, int size, int incr)
 {
   return Map<Matrix<T,Dynamic,1>, 0, InnerStride<Dynamic> >(data, size, InnerStride<Dynamic>(incr));
 }
 
 template<typename T>
-Map<Matrix<T,Dynamic,1> > vector(T* data, int size)
+Map<const Matrix<T,Dynamic,1>, 0, InnerStride<Dynamic> > make_vector(const T* data, int size, int incr)
+{
+  return Map<const Matrix<T,Dynamic,1>, 0, InnerStride<Dynamic> >(data, size, InnerStride<Dynamic>(incr));
+}
+
+template<typename T>
+Map<Matrix<T,Dynamic,1> > make_vector(T* data, int size)
 {
   return Map<Matrix<T,Dynamic,1> >(data, size);
 }
 
 template<typename T>
+Map<const Matrix<T,Dynamic,1> > make_vector(const T* data, int size)
+{
+  return Map<const Matrix<T,Dynamic,1> >(data, size);
+}
+
+template<typename T>
 T* get_compact_vector(T* x, int n, int incx)
 {
   if(incx==1)
     return x;
 
-  T* ret = new Scalar[n];
-  if(incx<0) vector(ret,n) = vector(x,n,-incx).reverse();
-  else       vector(ret,n) = vector(x,n, incx);
+  typename Eigen::internal::remove_const<T>::type* ret = new Scalar[n];
+  if(incx<0) make_vector(ret,n) = make_vector(x,n,-incx).reverse();
+  else       make_vector(ret,n) = make_vector(x,n, incx);
   return ret;
 }
 
@@ -135,8 +153,8 @@
   if(x_cpy==x)
     return 0;
 
-  if(incx<0) vector(x,n,-incx).reverse() = vector(x_cpy,n);
-  else       vector(x,n, incx)           = vector(x_cpy,n);
+  if(incx<0) make_vector(x,n,-incx).reverse() = make_vector(x_cpy,n);
+  else       make_vector(x,n, incx)           = make_vector(x_cpy,n);
   return x_cpy;
 }