# Ticket #3293 (closed Bugs: fixed)

## Addition of a matrix with resized identity matrix

Reported by: | eva.ketelaer@… | Owned by: | guwi17 |
---|---|---|---|

Milestone: | Boost 1.41.0 | Component: | uBLAS |

Version: | Boost 1.37.0 | Severity: | Problem |

Keywords: | resize matrix addition | Cc: |

### Description

Hello,

I have an identity matrix of size m. I add it to another matrix. It works. Then a I resize both matrixes to size m-1 x m-1 and I cannot add the matrices.

I used the following code:

#include <boost/numeric/ublas/io.hpp> #include <boost/numeric/ublas/matrix.hpp>

namespace ublas = boost::numeric::ublas;

int main(int argc, char *argv[]) {

int m=6; ublas::matrix<double> H(m, m); ublas::identity_matrix<double> I(m), J(m-1);

for(int i=0; i<m; ++i)

for(int j=0; j<m; ++j)

H(i,j)=i+j;

H += I;

H.resize(m-1,m-1,true); I.resize(m-1,true);

for(int i=0; i<m-1; ++i)

for(int j=0; j<m-1; ++j)

H(i,j)=i+j;

H += I;

return 0;

} I get the error: Check failed in file /usr/include/boost/numeric/ublas/matrix.hpp at line 2545: it_ < (*this) ().size1 () terminate called after throwing an instance of 'boost::numeric::ublas::bad_index'

what(): bad index

I checked the sizes of the matrices and everything seems to be correct. I use the boost version 1.37.0 in ubuntu 9.04.

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A fast debugging suggests that the problem is with matrix resize, where size_common_ is not updated along with size1_ and size2_