On 11/14/2012 04:50 PM, Stephan Petzchen wrote:
Hi Peter,
thanks for your reply.
Here is my code:
uint coffset=4;
/// 1 1 1 1 1 1 1
/// 2 2 2 2 2 2 2
/// 3 3 3 3 3 3 3
/// 4 4 4 4 4 4 4
gsl_matrix* m=gsl_matrix_calloc(4,7);
for(int i=0;i < m->rows; i++)
for(int j=0;j < m->columns; j++)
m->data[i * m->tda + j]=i+1;
//Expected:
/// x x x x 1 x x
/// x x x x 2 x x
/// x x x x 3 x x
/// x x x x 3 x x
gsl_vector* v = gsl_vector_alloc_col_from_matrix(m,coffset);
/// But GSL gives:
/// x x x x 1 1 1
/// 1 x x x x x x
/// x x x x x x x
/// x x x x x x x
for(int i=0;i < v->size; i++)
Assert.AreEqual(m->data[i * m->tda + coffset],v->data[i]);
Here is the problem. Rather than access data in 'v' directly, you should
access the vector with function
gsl_vector_const_ptr(v, i);
which will take the stride into account which is 7 in this case.
Hope that helps.
Cheers,
Peter
