/*
   testpafit.c

   Example program for the computation of piece-wise analytic fits to
   probability distribution functions, based on sample data.

   Ramses van Zon, December 5, 2009

   Reference:
   [] Ramses van Zon and Jeremy Schofield, "Constructing smooth
      potentials of mean force, radial distribution functions and
      probability densities from sampled data", 
      arxiv.0912.0465 [cond-mat.stat-mech].
*/
#include <stdio.h>
#include <stdlib.h>
#include "pa.h"

const int     km = 21;   /* maximum number of intervals */
const int     mm = 14;   /* maximum number of Fourier modes per interval */
const double  qm = 0.6;  /* satisfactory value for Q */

int main( int argc, char **argv )
{
  int           m, n;
  double        q, y, y1, y2, dy, *r;
  struct Pafit  *fit;

  r = readbinfile(argv[1], &y1, &y2, &m, &n);

  printf("#Read %d numbers from file %s\n", n, argv[1]);
  printf("#y1=%6.3f y2=%6.3f m=%d\n", y1, y2, m);
  printf("#Performing pa analysis\n");

  fit = paalloc(km,mm);
  pasort(n,r);
  q = pafit(n,r,qm,km,mm,1,fit);
  free(r);

  printf("#Writing distribution at %d points\n", m);

  dy = (y2-y1)/m;
  for (y = y1;y <= y2; y += dy)
    printf("%f %f %f\n", y, papd(y,fit), pacd(y,fit));

  printf("#Parameters (q=%f):\n", q);

  pawrite(stdout,fit);
  pafree(fit);
}