/* MX LIBRARY FUNCTION:  mxqdphot0_qdb5_vf5
 *
 * PURPOSE:  
 *
 *   determine iterative median sky background level and number of pixels used
 *
 * AUTHOR:  K. J. Mighell (mighell@noao.edu)
 *
 * LANGUAGE:  ANSI C
 *
 * DOCUMENTATION:  http://www.noao.edu/staff/mighell/mx
 *
 * DATE:  20000316
 *
 * MOD:  2
 * 
 * Copyleft (L) 2000 Kenneth John Mighell
 */

#include <mx.h>
#include "mxqdphot.h"

void mxqdphot0_qdb5_vf5 (
  double **pxm, 
  int x1, 
  int y1, 
  double *bkg_, 
  int *bkgn_
){

  char mxfunc[] = "mxqdphot0_qdb5_vf5";

  double bkg;
  int bkgn;
  double mean;
  int mean_n;
#define	SIZE 56
  double bv[SIZE];
  double tmpv[SIZE];
  int xxx[SIZE] = {
          3, 4, 5, 6, 7, 8, 9,
          3, 4, 5, 6, 7, 8, 9,
    1, 2,                     10,11,
    1, 2,                     10,11,
    1, 2,                     10,11,
    1, 2,                     10,11,
    1, 2,                     10,11,
    1, 2,                     10,11,
    1, 2,                     10,11,
          3, 4, 5, 6, 7, 8, 9,
          3, 4, 5, 6, 7, 8, 9
  };
  int yyy[SIZE] = {
          1, 1, 1, 1, 1, 1, 1,
          2, 2, 2, 2, 2, 2, 2,
    3, 3,                      3, 3,
    4, 4,                      4, 4,
    5, 5,                      5, 5, 
    6, 6,                      6, 6, 
    7, 7,                      7, 7,
    8, 8,                      8, 8,
    9, 9,                      9, 9,
         10,10,10,10,10,10,10,
         11,11,11,11,11,11,11
  };
  int xx[11+1]; /* SPP->C: 0th element added to simplify conversion */
  int yy[11+1]; /* SPP->C: 0th element added to simplify conversion */
  double px;
  int k;
  double mdn;
  double adv;
  int tmp_n;
  int x;
  int y;

  x = x1 - 1; /* SPP->C: C uses a zero-offset index */
  xx[1] = x - 5;
  xx[2] = x - 4;
  xx[3] = x - 3;
  xx[4] = x - 2;
  xx[5] = x - 1;
  xx[6] = x;
  xx[7] = x + 1;
  xx[8] = x + 2;
  xx[9] = x + 3;
  xx[10] = x + 4;
  xx[11] = x + 5;

  y = y1 - 1; /* SPP->C: C uses a zero-offset index */
  yy[1] = y - 5;
  yy[2] = y - 4;
  yy[3] = y - 3;
  yy[4] = y - 2;
  yy[5] = y - 1;
  yy[6] = y;
  yy[7] = y + 1;
  yy[8] = y + 2;
  yy[9] = y + 3;
  yy[10] = y + 4;
  yy[11] = y + 5;

  mean = 0;
  for (k=0; k<SIZE; ++k) {
    px = pxm[yy[yyy[k]]][xx[xxx[k]]];
    bv[k] = px;
    mean = mean + px;
  }

  mxqdphot0_qdimdn_vf6 (bv, SIZE, tmpv, &tmp_n, &mdn, &adv); 

  mean_n = SIZE;
  mean = mean / mean_n;

  bkg = mdn;
  bkgn = tmp_n;

ok:
  *bkg_ = bkg;
  *bkgn_ = bkgn;
  return;

#undef SIZE
}
/* end-of-file */