diff --git a/blas/level1_real_impl.h b/blas/level1_real_impl.h
new file mode 100644
index 0000000..8acecdf
--- /dev/null
+++ b/blas/level1_real_impl.h
@@ -0,0 +1,100 @@
+// This file is part of Eigen, a lightweight C++ template library
+// for linear algebra.
+//
+// Copyright (C) 2009-2010 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
+// with this file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+#include "common.h"
+
+// computes the sum of magnitudes of all vector elements or, for a complex vector x, the sum
+// res = |Rex1| + |Imx1| + |Rex2| + |Imx2| + ... + |Rexn| + |Imxn|, where x is a vector of order n
+RealScalar EIGEN_BLAS_FUNC(asum)(int *n, RealScalar *px, int *incx)
+{
+//   std::cerr << "_asum " << *n << " " << *incx << "\n";
+
+  Scalar* x = reinterpret_cast<Scalar*>(px);
+
+  if(*n<=0) return 0;
+
+  if(*incx==1)  return vector(x,*n).cwiseAbs().sum();
+  else          return vector(x,*n,std::abs(*incx)).cwiseAbs().sum();
+}
+
+// computes a vector-vector dot product.
+Scalar EIGEN_BLAS_FUNC(dot)(int *n, RealScalar *px, int *incx, RealScalar *py, int *incy)
+{
+//   std::cerr << "_dot " << *n << " " << *incx << " " << *incy << "\n";
+
+  if(*n<=0) return 0;
+
+  Scalar* x = reinterpret_cast<Scalar*>(px);
+  Scalar* y = reinterpret_cast<Scalar*>(py);
+
+  if(*incx==1 && *incy==1)    return (vector(x,*n).cwiseProduct(vector(y,*n))).sum();
+  else if(*incx>0 && *incy>0) return (vector(x,*n,*incx).cwiseProduct(vector(y,*n,*incy))).sum();
+  else if(*incx<0 && *incy>0) return (vector(x,*n,-*incx).reverse().cwiseProduct(vector(y,*n,*incy))).sum();
+  else if(*incx>0 && *incy<0) return (vector(x,*n,*incx).cwiseProduct(vector(y,*n,-*incy).reverse())).sum();
+  else if(*incx<0 && *incy<0) return (vector(x,*n,-*incx).reverse().cwiseProduct(vector(y,*n,-*incy).reverse())).sum();
+  else return 0;
+}
+
+// computes the Euclidean norm of a vector.
+// FIXME
+Scalar EIGEN_BLAS_FUNC(nrm2)(int *n, RealScalar *px, int *incx)
+{
+//   std::cerr << "_nrm2 " << *n << " " << *incx << "\n";
+  if(*n<=0) return 0;
+
+  Scalar* x = reinterpret_cast<Scalar*>(px);
+
+  if(*incx==1)  return vector(x,*n).stableNorm();
+  else          return vector(x,*n,std::abs(*incx)).stableNorm();
+}
+
+int EIGEN_BLAS_FUNC(rot)(int *n, RealScalar *px, int *incx, RealScalar *py, int *incy, RealScalar *pc, RealScalar *ps)
+{
+//   std::cerr << "_rot " << *n << " " << *incx << " " << *incy << "\n";
+  if(*n<=0) return 0;
+
+  Scalar* x = reinterpret_cast<Scalar*>(px);
+  Scalar* y = reinterpret_cast<Scalar*>(py);
+  Scalar c = *reinterpret_cast<Scalar*>(pc);
+  Scalar s = *reinterpret_cast<Scalar*>(ps);
+
+  StridedVectorType vx(vector(x,*n,std::abs(*incx)));
+  StridedVectorType vy(vector(y,*n,std::abs(*incy)));
+
+  Reverse<StridedVectorType> rvx(vx);
+  Reverse<StridedVectorType> rvy(vy);
+
+       if(*incx<0 && *incy>0) internal::apply_rotation_in_the_plane(rvx, vy, JacobiRotation<Scalar>(c,s));
+  else if(*incx>0 && *incy<0) internal::apply_rotation_in_the_plane(vx, rvy, JacobiRotation<Scalar>(c,s));
+  else                        internal::apply_rotation_in_the_plane(vx, vy,  JacobiRotation<Scalar>(c,s));
+
+
+  return 0;
+}
+
+/*
+// performs rotation of points in the modified plane.
+int EIGEN_BLAS_FUNC(rotm)(int *n, RealScalar *px, int *incx, RealScalar *py, int *incy, RealScalar *param)
+{
+  Scalar* x = reinterpret_cast<Scalar*>(px);
+  Scalar* y = reinterpret_cast<Scalar*>(py);
+
+  // TODO
+
+  return 0;
+}
+
+// computes the modified parameters for a Givens rotation.
+int EIGEN_BLAS_FUNC(rotmg)(RealScalar *d1, RealScalar *d2, RealScalar *x1, RealScalar *x2, RealScalar *param)
+{
+  // TODO
+
+  return 0;
+}
+*/