#include <math.h>
#include <stdio.h>
#include <gsl/gsl_matrix.h>
#include <gsl/gsl_blas.h>
     
int main(void)
{
size_t 			i, j;
double 			d;
gsl_matrix	* 	m=gsl_matrix_alloc(10,10);

for(i=0; i<10; i++)
  {
  for(j=0; j<10; j++)
    {
    gsl_matrix_set (m, i, j, sin(i) + cos(j));
    }
  } 
for(j=0; j<10; j++)
  {
  gsl_vector_view column = gsl_matrix_column (m, j);
  d = gsl_blas_dnrm2 (&column.vector);
  printf ("matrix column %d, norm = %g\n", j, d);
  }
     
gsl_matrix_free (m);
     
return 0;
}