Re: [Help-gsl] Help with linking / loading libraries on Ubuntu 10.10

[Rhys Ulerich]

Hi Randall,

Responding to your note with the help-gsl list CCed...

On Fri, Feb 24, 2012 at 11:25 AM, Rhys Ulerich <address@hidden> wrote:
>> I tried writing a simple C program to use this function (a few other gsl
>> functions) and find that I can use other gsl function fine but cannot use
>> the gsl_poly_complex_eval. Again, in the C program I get a
>> gsl_poly_complex_eval() undefined symbol error.
>
> Would you please send the complete source for your short sample code?

Turns out the problem was a combination of mixing gsl_complex* with
gsl_complex as well as using gsl_poly_complex_eval when you wanted
gsl_complex_poly_complex_eval.  Here's a working version of your
sample code:

#include <stdio.h>
#include <stdlib.h>

#include <gsl/gsl_complex.h>
#include <gsl/gsl_complex_math.h>
#include <gsl/gsl_math.h>
#include <gsl/gsl_cblas.h>
#include <gsl/gsl_poly.h>

void testPoly(void)
{
    int i = 0;
    int r = 0;
    double x[3];
    double a = 1.0;
    double b = 2.0;
    double c = 1.0;

    x[0] = 0.0;
    x[1] = 0.0;
    x[2] = 0.0;
    r = gsl_poly_solve_quadratic(a, b, c, &x[0], &x[1]);
    printf("r = %d\n a = %f, b = %f, c = %f\n x[0] = %f, x[1] =
%f\n\n", r, a, b, c, x[0], x[1]);


    x[0] = 0.0;
    x[1] = 0.0;
    x[2] = 0.0;
    r = gsl_poly_solve_cubic(a, b, c, &x[0], &x[1], &x[2]);
    printf("r = %d\n a = %f, b = %f, c = %f\n x[0] = %f, x[1] = %f,
x[2] = %f\n\n", r, a, b, c, x[0], x[1], x[2]);

    return;

}

void testComplex(void)
{
    gsl_complex a, b, c[5];
    gsl_complex r, n;

    GSL_SET_COMPLEX(&a, 10, 20);
    GSL_SET_COMPLEX(&b, 5, 10);
    GSL_SET_REAL(&a, 12);
    r = gsl_complex_add(a, b);
    printf("Adding Complex Numbers\n");
    printf("A.Real: %f\n", GSL_REAL(a));
    printf("A.Imag: %f\n", GSL_IMAG(a));
    printf("\nARCCSC Function\n");
    r = gsl_complex_arccsc(a);
    printf("A.Real: %f\n", GSL_REAL(r));
    printf("A.Imag: %f\n", GSL_IMAG(r));

    printf("\nAdd Real\n");
    r = gsl_complex_add_real(a, 10.25);
    printf("A.Real: %f\n", GSL_REAL(r));
    printf("A.Imag: %f\n", GSL_IMAG(r));



    printf("gsl_poly_complex_eval(c, 5, z->number)\n");
    c[0].dat[0] = 1.0;
    c[0].dat[1] = 0.5;

    c[0].dat[0] = 2.0;
    c[0].dat[1] = 0.1;

    c[0].dat[0] = 3.0;
    c[0].dat[1] = 1.5;

    c[0].dat[0] = 4.0;
    c[0].dat[1] = 2.0;

    c[0].dat[0] = 5.0;
    c[0].dat[1] = 2.5;

    n = gsl_complex_poly_complex_eval(c, 5, a);

    printf("r.real = %f, r.imag = %f\n", GSL_REAL(n), GSL_IMAG(n));

    return;
}

int main()
{
    testComplex();

    testPoly();

    return 0;
}


Hope that helps,
Rhys