gsl matrix

[Brian Gough]

Juan Jose Gomez Cadenas writes:
 > The first one has to do with the absence in the gsl-0.9 library of a
 > function of the type: 
 > 
 > double * gsl_matrix_ptr(const gsl_matrix * m, const size_t i, const size_t
 > j);
 >
 > Could this function be (re)-added to the package?

Good point, I've now added them in the CVS version.  I haven't tested
them so you will need to check that they work correctly.

 > Notice that I use the gsl_error function rather than the macros used in
 > similar functions (that would not work here).

I used the GSL_ERROR_NULL macro to return a NULL pointer for
out-of-range arguments.  I think this should work ok.

 > The second "problem" that I have found appears when
 > compiling my wrapper class:
 > 
 > /usr/local/include/gsl/gsl_vector_long_double.h:58: warning: non-static
 > const member `const
 > gsl_vector_long_double {anonymous union}::vector' in class without a
 > constructor

Maybe we'll need to have a empty constructor inside an #ifdef
__cplusplus .. #endif to get rid of the warning.