Re: [Bug-gsl] multiwlinear.c:73: ERROR: size of workspace does not match size of observation matrix

[Patrick Alken]

Thanks for reporting this, it is indeed a bug. My apologies, I had
rewritten the linear least squares routines recently and didn't make
proper tests for the wlinear_svd routine. I will work on a fix asap. In
the meantime, you can replace the gsl_multifit_wlinear_svd call with:

gsl_multifit_wlinear(A, w, y, x, cov, &chisq, wsp);

which should work as a temporary fix.

On 02/10/2018 12:26 AM, Vlad Koli wrote:
> Hi,
>
> In Debian 9  (gsl 2.3) compilation/execution of the following test-file 
> causes 
> error messages. In Debian 7 (gsl ???)  it worked fine. The same error message
> also appears in other my programs that worked well in Debian 7 and 
> were recompiled in Debian 9.
>
> ** compilation:
>
>  cc -o a -lm -lgsl -lgslcblas linfit-pseudoinv.c 
>
> **  execution: 
>
>  ./a
>
> ** result:
>
>> gsl: multiwlinear.c:73: ERROR: size of workspace does not match size of 
>> observation matrix
>> Default GSL error handler invoked.
>> Aborted
> Thank you in advance.
>
> Vladimir
>
> ----- begin file: linfit-pseudoinv.c:---------
> // compile:
> //     cc -o a -lm -lgsl -lgslcblas linfit-pseudoinv.c 
> #include <stdio.h>
> #include <gsl/gsl_multifit.h>
>
>
> double tol = 1.e-08; // tolerance
>
> main()
> {
>      
>     int n = 3; // observations
>     int m = 2; // parameters 
>
>     size_t rank;   // rank
>     double chisq;  // sum of squares of residuals
>
>     // allocate:
>     gsl_vector *x = gsl_vector_alloc(m); // solution 
>     gsl_vector *y = gsl_vector_alloc(n); // data 
>     gsl_vector *w = gsl_vector_alloc(n); // weights
>
>     gsl_matrix *A = gsl_matrix_alloc(n, m);
>     gsl_matrix *cov = gsl_matrix_alloc(m, m); // covariances
>
>     gsl_multifit_linear_workspace* wsp = gsl_multifit_linear_alloc (n, m);
>
>
>     // set matrix
>     gsl_matrix_set(A, 0,0, 1.);
>     gsl_matrix_set(A, 0,1, 1.);
>     gsl_matrix_set(A, 1,0, 2.);
>     gsl_matrix_set(A, 1,1, 2.);
>     gsl_matrix_set(A, 2,0, 3.);
>     gsl_matrix_set(A, 2,1, 3.);
>
>     // set data 
>     gsl_vector_set(y, 0, 1.);
>     gsl_vector_set(y, 1, 2.);
>     gsl_vector_set(y, 2, 3.1);
>
>     // set weights
>     gsl_vector_set_all(w,1.);
>     gsl_vector_set(w, 0, 0.);
>     gsl_vector_set(w, 2, 100.);
>
>
>     gsl_multifit_wlinear_svd (A, w, y,  tol, &rank, x, cov, &chisq, wsp);
>  
>
>     printf("solution: x=%.4f  y=%.4f   (rank=%d, chi2=%.3f)\n", 
>             gsl_vector_get(x,0), gsl_vector_get(x,1), rank, chisq);
>
>
> }
> ----- end file: linfit-pseudoinv.c:---------
>
>
>