gsl_cspline_init bug?

["R. Sean Bowman" <sean@rootnode.com>]

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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;
}