chkphase.c

/* $Id$
 *
 *  (C) 2003-2007, Friedrich Woeger <woeger@kis.uni-freiburg.de>,
 *  Kiepenheuer-Institut für Sonnenphysik, Freiburg (Breisgau), Germany
 *  All rights reserved.
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/* =====================================================================
**
** core speckle routines
**
** =====================================================================
**
** uses:  fftw3 library:
**   http://www.fftw.org
**
**   Library for fast fourier transform
**
** =====================================================================
**
** Author:  F. Woeger
**   Kiepenheuer-Institut fuer Sonnenphysik
**   Freiburg, Germany
**
** Written 17. 06. 2003
**
** =====================================================================
*/

#include "speckle_core.h"


float chkphase(slaveinfo l, float *phs)
{
    static long INIT = 0;
    static float *old = NULL, *new = NULL;

    float *tmp = NULL;
    long i;
    float t, var = 0.0;

    if (INIT / l.sfsizex != l.sfsizey) {
		if (old != NULL)
			free(old);
		if (new != NULL)
			free(new);
		INIT = l.sfsizex * l.sfsizex;
		old = (float *) calloc(INIT, sizeof(float));
		new = (float *) calloc(INIT, sizeof(float));
    }

    for (i = 0; i < INIT; i++) {
		new[i] = atan2(phs[2 * i + 1], phs[2 * i]);
		t = (old[i] - new[i]);
		var += t * t;
    }

    // some fun stuff: pointer bending!
    tmp = old;
    old = new;
    new = tmp;
    tmp = NULL;

    return (var);
}