Assigning complex values in gsl

Question

I am trying to use GSL for complex numbers, complex vectors and complex matrices in my project. I am using VS2010 and I added the address

Answer 1

It would be better if you published all your code here, therefore, I immediately used this code from the lowest of the examples of the GSL. I made some small changes:

#include <stdio.h>
#include <gsl/gsl_math.h>
#include <gsl/gsl_eigen.h>

int main(void)
{
double data[] = { -1.0, 1.0, -1.0, 1.0,
    -8.0, 4.0, -2.0, 1.0,
    27.0, 9.0, 3.0, 1.0,
    64.0, 16.0, 4.0, 1.0 };

gsl_matrix_view m
    = gsl_matrix_view_array(data, 4, 4);

gsl_vector_complex *eval = gsl_vector_complex_alloc(4);
gsl_matrix_complex *evec = gsl_matrix_complex_alloc(4, 4);

gsl_eigen_nonsymmv_workspace * w = gsl_eigen_nonsymmv_alloc(4);

gsl_eigen_nonsymmv(&m.matrix, eval, evec, w);

gsl_eigen_nonsymmv_free(w);

gsl_eigen_nonsymmv_sort(eval, evec, GSL_EIGEN_SORT_ABS_DESC);

{
    int i, j;

    for (i = 0; i < 4; i++)
    {
        gsl_complex eval_i
            = gsl_vector_complex_get(eval, i);
        gsl_vector_complex_view evec_i
            = gsl_matrix_complex_column(evec, i);

        printf("\n eigenvalue = %g + %gi\n",
            GSL_REAL(eval_i), GSL_IMAG(eval_i));
        printf(" eigenvector = \n");
        for (j = 0; j < 4; ++j)
        {
            gsl_complex z =
                gsl_vector_complex_get(&evec_i.vector, j);
            printf("        %g + %gi\n", GSL_REAL(z), GSL_IMAG(z));
        }
    }
}

gsl_vector_complex_free(eval);
gsl_matrix_complex_free(evec);

system("pause");

return 0;
}

Output of this code: (from the red arrow and below there is a mismatch with the expected output in the GSL example) To get my output, you need to IDE (I use Visual Studio 2015):

1. into "your_application" Property pages -> Configuration Properties -> VC++ Directories -> (right pane)in line Executable Directories type: C:\Users\ ...(your GSL build directory path)... \gsl\Release;$(ExecutablePath)
2. ibid. in line Include Directories type: C:\Users\ ...(your GSL build directory path)... \gsl;$(IncludePath)
3. ibid. in line Library Directories type: C:\Users\ ...(your GSL build directory path)... \gsl\Release;$(LibraryPath)
4. Below, in the left pane, select C/C++ -> Peprocessor -> (right pane) in line Preprocessor Defenition type: WIN32;_DEBUG;_CONSOLE;GSL_DLL;%(PreprocessorDefinitions) (I use Debug mode, created empty console application). Save settings (press "Apply" and "OK" buttons)
5. Copy and put into Debug directories of your application project folder gsl.dll and gslcblas.dll from C:\Users\ ...(your GSL build directory path)... \gsl\Release directory
6. Buld your application and run it
7. NOTE!: In the beginning it is best to rebuild GSL with your compiler for the target application - then the work will be guaranteed.

Good luck!