* gsl_cspline_init bug?
@ 2002-11-05 23:11 R. Sean Bowman
2002-11-06 7:36 ` Kenneth Geisshirt
2002-11-06 16:05 ` Gerard Jungman
0 siblings, 2 replies; 3+ messages in thread
From: R. Sean Bowman @ 2002-11-05 23:11 UTC (permalink / raw)
To: gsl-discuss
[-- Attachment #1: Type: TEXT/PLAIN, Size: 529 bytes --]
hello
I think I've found a bug in gsl_cspline_init. It appears to want a
minimum of two points, but in this case a variable "sys_size" gets set to
0 in gsl_cspline_init, which somebody doesn't like later. I get the
message
gsl: view_source.c:28: ERROR: vector length n must be positive integer
Default GSL error handler invoked.
Aborted
Attached is a small program which elicits this behavior on my linux box.
Isn't this a problem? Shouldn't csplines need more than two points to do
interpolation?
Thanks a bunch!
Sean
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#include <stdlib.h>
#include <math.h>
#include <gsl/gsl_errno.h>
#include <gsl/gsl_spline.h>
#define PTS 2
int main (int argc, char** argv){
int i;
double xi, yi, x[PTS], y[PTS];
for (i = 0; i < PTS; i++){
x[i] = i + 0.5 * sin (i);
y[i] = i + cos (i * i);
}
{
gsl_interp_accel *acc = gsl_interp_accel_alloc ();
gsl_spline *spline = gsl_spline_alloc (gsl_interp_cspline, PTS);
gsl_spline_init (spline, x, y, PTS);
gsl_spline_free (spline);
gsl_interp_accel_free(acc);
}
return 0;
}
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: gsl_cspline_init bug?
2002-11-05 23:11 gsl_cspline_init bug? R. Sean Bowman
@ 2002-11-06 7:36 ` Kenneth Geisshirt
2002-11-06 16:05 ` Gerard Jungman
1 sibling, 0 replies; 3+ messages in thread
From: Kenneth Geisshirt @ 2002-11-06 7:36 UTC (permalink / raw)
To: gsl-discuss
On Tue, 5 Nov 2002, R. Sean Bowman wrote:
> gsl: view_source.c:28: ERROR: vector length n must be positive integer
> Default GSL error handler invoked.
> Aborted
I can reproduce the error message. But if I set PTS to 10 (as the example
in the manual), the problem disappears.
> Isn't this a problem? Shouldn't csplines need more than two points to do
> interpolation?
Yes, and maybe we should validate the input parameters :-).
Kneth
--
Kenneth Geisshirt, M.Sc., Ph.D. http://kenneth.geisshirt.dk
Grøndals Parkvej 2A, 3. sal kenneth@geisshirt.dk
DK-2720 Vanløse +45 38 87 78 38
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: gsl_cspline_init bug?
2002-11-05 23:11 gsl_cspline_init bug? R. Sean Bowman
2002-11-06 7:36 ` Kenneth Geisshirt
@ 2002-11-06 16:05 ` Gerard Jungman
1 sibling, 0 replies; 3+ messages in thread
From: Gerard Jungman @ 2002-11-06 16:05 UTC (permalink / raw)
To: R. Sean Bowman; +Cc: gsl-discuss
Fixed in CVS.
Thanks for the report.
--
G. Jungman
On Tue, 2002-11-05 at 19:42, R. Sean Bowman wrote:
> hello
>
> I think I've found a bug in gsl_cspline_init. It appears to want a
> minimum of two points, but in this case a variable "sys_size" gets set to
> 0 in gsl_cspline_init, which somebody doesn't like later. I get the
> message
>
> gsl: view_source.c:28: ERROR: vector length n must be positive integer
> Default GSL error handler invoked.
> Aborted
>
> Attached is a small program which elicits this behavior on my linux box.
>
> Isn't this a problem? Shouldn't csplines need more than two points to do
> interpolation?
>
> Thanks a bunch!
> Sean
>
> ----
>
> #include <stdlib.h>
> #include <math.h>
> #include <gsl/gsl_errno.h>
> #include <gsl/gsl_spline.h>
>
>
> #define PTS 2
>
> int main (int argc, char** argv){
> int i;
> double xi, yi, x[PTS], y[PTS];
>
> for (i = 0; i < PTS; i++){
> x[i] = i + 0.5 * sin (i);
> y[i] = i + cos (i * i);
> }
>
> {
> gsl_interp_accel *acc = gsl_interp_accel_alloc ();
> gsl_spline *spline = gsl_spline_alloc (gsl_interp_cspline, PTS);
> gsl_spline_init (spline, x, y, PTS);
>
> gsl_spline_free (spline);
> gsl_interp_accel_free(acc);
> }
>
> return 0;
> }
^ permalink raw reply [flat|nested] 3+ messages in thread
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2002-11-05 23:11 gsl_cspline_init bug? R. Sean Bowman
2002-11-06 7:36 ` Kenneth Geisshirt
2002-11-06 16:05 ` Gerard Jungman
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