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

[Patrick Alken]

Vlad,

  I have uploaded a fix for this issue to the git repository. Now when I
run your original program I get this output:

$ ./test
solution: x=0.5166  y=0.5166   (rank=1, chi2=0.004)

Thanks,
Patrick

On 02/10/2018 10:52 AM, Patrick Alken wrote:
> So as it turns out, the gsl_multifit_wlinear_svd function should be
> deprecated, and I removed it from the documentation, but kept it around
> for legacy reasons - without testing it properly!
>
> The new function is called gsl_multifit_wlinear_tsvd, and you can use
> this call in your code:
>
> gsl_multifit_wlinear_tsvd(A, w, y, tol, x, cov, &chisq, &rank, wsp);
>
> This should make your program run correctly. In the meantime I will
> figure out what to do with gsl_multifit_wlinear_svd - maybe just make it
> a wrapper function for the new tsvd call.
>
> Sorry for the trouble,
> Patrick
>
> On 02/10/2018 10:28 AM, Patrick Alken wrote:
>> 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:---------
>>>
>>>
>>>
>