From 8e050bd68163a64e0252eed66e215baafb6c11ca Mon Sep 17 00:00:00 2001
From: Desire NUENTSA <desire.nuentsa_wakam@inria.fr>
Date: Wed, 22 May 2013 10:43:12 +0200
Subject: [PATCH] Optimize Sparse setIdentity and add a unit test

---
 Eigen/src/SparseCore/SparseMatrix.h | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/Eigen/src/SparseCore/SparseMatrix.h b/Eigen/src/SparseCore/SparseMatrix.h
index d93dffb48..072578132 100644
--- a/Eigen/src/SparseCore/SparseMatrix.h
+++ b/Eigen/src/SparseCore/SparseMatrix.h
@@ -677,9 +677,10 @@ class SparseMatrix
     inline void setIdentity()
     {
       eigen_assert(rows() == cols() && "ONLY FOR SQUARED MATRICES");
-      this->setZero();
-      for (int j = 0; j < rows(); j++)
-          this->insert(j,j) = Scalar(1.0);
+      this->m_data.resize(rows());
+      Eigen::Map<Matrix<Index, Dynamic, 1> >(&this->m_data.index(0), rows()).setLinSpaced(0, rows()-1);
+      Eigen::Map<Matrix<Scalar, Dynamic, 1> >(&this->m_data.value(0), rows()).setOnes();
+      Eigen::Map<Matrix<Index, Dynamic, 1> >(this->m_outerIndex, rows()+1).setLinSpaced(0, rows());
     }
     inline SparseMatrix& operator=(const SparseMatrix& other)
     {