[Help-gsl] Declaring GSL Matrices and Vectors Within a Structure

[Matthew Boulton]

Hello. I'm wondering what is the best way to declare a GSL vector or 
matrix contained within a structure?

For example, at present I have a structure defined as follows:

typedef struct
{
 int       x,y;
 DATA_TYPE **vectors;
 DATA_TYPE *area;
 double    **mat;
 double    *scprod;
 double    sum;
 double    chi2;
 double    norm;
 double    diff;
 char      keep;
} stamp_struct;

stamp_struct *stamps;

where DATA_TYPE defines a double precision variable. Now currently the 
code allocates memory using malloc for the vectors and matrices. For 
example:

for( i = 0 ; i < stamp_number ; i++ )
{
   for( j = 0 ; j < ncomp_kernel + nbg_vectors ; j++ )
   {
   stamps[i].vectors = (DATA_TYPE **)malloc( ( ncomp_kernel + 
nbg_vectors ) * sizeof(DATA_TYPE *)  );
   stamps[i].vectors[j] = (DATA_TYPE *)malloc( stamp_size * stamp_size 
* sizeof(DATA_TYPE) );
   }
}


I'm assuming the structure declaration "DATA_TYPE **vectors;" can be 
replaced with "gsl_matrix *vectors". However I'm not sure how I can 
replace the above code. Usually I would have something like the following:


gsl_matrix *stamps.vectors = gsl_matrix_calloc( ncomp_kernel + 
nbg_vectors , stamp_size * stamp_size );

but this doesn't look right. Because it is a structure do I declare each 
bit before and after the . as a separate GSL vector? Sorry if this seems 
like an obvious question!

Kind Regards,

Matt