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Re: Problems with creating executables using GSL with RadHat Linux
- To: Mihajlo <mjovanov at ECECS dot UC dot EDU>, gsl-discuss at sourceware dot cygnus dot com
- Subject: Re: Problems with creating executables using GSL with RadHat Linux
- From: Jon McAuliffe <jon at vindigo dot com>
- Date: Mon, 17 Apr 2000 10:01:50 -0400
- Organization: Vindigo
- References: <38F795F8.E8A6134D@ececs.uc.edu>
this may sound silly, but try putting the gcc arguments on the
command line like this
gcc -L/usr/local/lib/gsl main.o -lgslroots
because (quoting from the man page)
For the link stage, all .o files corresponding to source
files, -l libraries, unrecognized filenames (including named
.o object files and .a archives) are passed to the linker
in command-line order.
which means that if you put main.o last on the command line,
none of its references to functions in libgslroots.a will
get resolved.
cheers
jon.
Mihajlo wrote:
>
> Hello,
>
> I wanted to try out GSL for some numerical equation solvers, but I am
> running into problems generating an executable for even a simple example
> code as given in
> http://sourceware.cygnus.com/gsl/ref/gsl-ref_9.html#SEC88. The
> installation seamed to have gone fine, the 'make check' script returned
> almost all tests passed except for the last portion (attached is a copy
> of the make_check.log file). However when I try to build an example
> executable I get into problems. Executing
>
> gcc -I/usr/local/include/gsl -c main.c
>
> seams to go fine, but when I do
>
> gcc -lgslroots -L/usr/local/lib/gsl main.o
>
> I get the following errors:
>
> [root@ash CS690]# gcc -lgslroots -L/usr/local/lib/gsl main.o
> main.o: In function `main':
> main.o(.text+0xf0): undefined reference to `sqrt'
> main.o(.text+0x148): undefined reference to `gsl_root_fsolver_brent'
> main.o(.text+0x14e): undefined reference to `gsl_root_fsolver_alloc'
> main.o(.text+0x15f): undefined reference to `gsl_root_fsolver_name'
> main.o(.text+0x1ae): undefined reference to `gsl_root_fsolver_iterate'
> main.o(.text+0x1bf): undefined reference to `gsl_root_fsolver_root'
> main.o(.text+0x1d2): undefined reference to `gsl_root_fsolver_interval'
> main.o(.text+0x1f8): undefined reference to `gsl_root_test_interval'
> collect2: ld returned 1 exit status
>
> ,even though the library file libgslroots.a seams to be loaded. I also
> did a 'grep' for some of the listed references and they are indeed
> present in the libgslroots.a file.
>
> I am attaching all three example files that I am trying to compile.
> What could be the problem?!
>
> Thanks for your help.
>
> ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
>
> double quadratic (double x, void *params)
> {
> struct quadratic_params *p = (struct quadratic_params *) params;
>
> double a = p->a;
> double b = p->b;
> double c = p->c;
>
> return (a * x + b) * x + c;
> }
>
> double quadratic_deriv (double x, void *params)
> {
> struct quadratic_params *p = (struct quadratic_params *) params;
>
> double a = p->a;
> double b = p->b;
> double c = p->c;
>
> return 2.0 * a * x + b;
> }
>
> void
> quadratic_fdf (double x, void *params, double *y, double *dy)
> {
> struct quadratic_params *p = (struct quadratic_params *) params;
>
> double a = p->a;
> double b = p->b;
> double c = p->c;
>
> *y = (a * x + b) * x + c;
> *dy = 2.0 * a * x + b;
> }
>
> ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
> struct quadratic_params {double a, b, c;};
> double quadratic (double x, void *params);
> double quadratic_deriv (double x, void *params);
> void quadratic_fdf (double x, void *params, double *y, double *dy);
>
> ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
> #include <stdio.h>
> #include <gsl_errno.h>
> #include <gsl_math.h>
> #include <gsl_roots.h>
>
> #include "demof.h"
> #include "demof.c"
>
> int
> main ()
> {
> int status;
> int iterations = 0, max_iterations = 100;
> gsl_root_fsolver *s;
> double r = 0, r_expected = sqrt (5.0);
> gsl_interval x = {0.0, 5.0};
> gsl_function F;
> struct quadratic_params params = {1.0, 0.0, -5.0};
>
> F.function = &quadratic;
> F.params = ¶ms;
>
> s = gsl_root_fsolver_alloc (gsl_root_fsolver_brent, &F, x);
>
> printf ("using %s method\n", gsl_root_fsolver_name (s));
>
> printf ("%5s [%9s, %9s] %9s %9s %10s %9s\n",
> "iter", "lower", "upper", "root", "actual", "err", "err(est)");
>
> do
> {
> iterations++;
> status = gsl_root_fsolver_iterate (s);
> r = gsl_root_fsolver_root (s);
> x = gsl_root_fsolver_interval (s);
> status = gsl_root_test_interval (x, 0, 0.001);
>
> if (status == GSL_SUCCESS)
> printf ("Converged:\n");
>
> printf ("%5d [%.7f, %.7f] %.7f %.7f %+.7f %.7f\n",
> iterations, x.lower, x.upper,
> r, r_expected, r - r_expected, x.upper - x.lower);
> }
> while (status == GSL_CONTINUE && iterations < max_iterations);
>
> }