profit.c

  if ((dprofit->guessradius = 0.5*dpsf->fwhm) < sqrtf((float)obj->dnpix))
    dprofit->guessradius = sqrtf((float)obj->dnpix);
  dprofit->guessaspect = obj->b/obj->a;
  dprofit->guessposang = obj->theta;

  profit_resetparams(dprofit);

/* Actual minimisation */
  fft_reset();

  dprofit->niter = profit_minimize(dprofit, PROFIT_MAXITER);

  if (dprofit->nlimmin)
    obj2->dprof_flag |= PROFLAG_MINLIM;
  if (dprofit->nlimmax)
    obj2->dprof_flag |= PROFLAG_MAXLIM;

  for (p=0; p<nparam; p++)
    dprofit->paramerr[p]= sqrt(dprofit->covar[p*(nparam+1)]);
 
  obj2->dprof_niter = dprofit->niter;

/* Now inject fitted parameters into the measurement model */
  fft_reset();
  profit_residuals(profit,field,wfield, 0.0, dprofit->paraminit, NULL);

/* Compute flux correction */
  sumn = sumd = 0.0;
  for (p=0; p<profit->nobjpix; p++)
    if (profit->objweight[p]>0 && profit->objpix[p]>-BIG)
      {
      w2 = profit->objweight[p]*profit->objweight[p] * profit->lmodpix[p];
      sumn += (double)(w2*profit->objpix[p]);
      sumd += (double)(w2*profit->lmodpix[p]);
      }

  ffac = (float)(sumn/sumd);
  obj2->flux_dprof = sumd!=0.0? dprofit->flux*ffac: 0.0f;
  obj2->fluxerr_dprof = sumd!=0.0? 1.0f/sqrtf((float)sumd): 0.0f;

  if (FLAG(obj2.dprof_chi2))
    {
/*-- Compute reduced chi2 on measurement image */
    pix = profit->lmodpix;
    for (p=profit->nobjpix; p--;)
      *(pix++) *= ffac;
    profit_compresi(profit, 0.0, profit->resi);
    obj2->dprof_chi2 = (profit->nresi > dprofit->nparam)?
		profit->chi2 / (profit->nresi - dprofit->nparam) : 0.0;
    }

/* clean up. */
  fft_reset();

  return;
  }


/****** profit_noisearea ******************************************************
PROTO	float profit_noisearea(profitstruct *profit)
PURPOSE	Return the equivalent noise area (see King 1983) of a model.
INPUT	Profile-fitting structure,
OUTPUT	Equivalent noise area, in pixels.
NOTES	-.
AUTHOR	E. Bertin (IAP)
VERSION	19/10/2010
 ***/
float	profit_noisearea(profitstruct *profit)
  {
   double	dval, flux,flux2;
   PIXTYPE	*pix;
   int		p;

  flux = flux2 = 0.0;
  pix = profit->lmodpix;
  for (p=profit->nobjpix; p--;)
    {
    dval = (double)*(pix++);
    flux += dval;
    flux2 += dval*dval;
    }

  return (float)(flux2>0.0? flux*flux / flux2 : 0.0);
  }


/****** profit_fluxcor ******************************************************
PROTO	void profit_fluxcor(profitstruct *profit, objstruct *obj,
			obj2struct *obj2)
PURPOSE	Integrate the flux within an ellipse and complete it with the wings of
		the fitted model.
INPUT		Profile-fitting structure,
		pointer to the obj structure,
		pointer to the obj2 structure.
OUTPUT	Model-corrected flux.
NOTES	-.
AUTHOR	E. Bertin (IAP)
VERSION	12/04/2011
 ***/
void	profit_fluxcor(profitstruct *profit, objstruct *obj, obj2struct *obj2)
  {
    checkstruct		*check;
    double		mx,my, dx,dy, cx2,cy2,cxy, klim,klim2, tvobj,sigtvobj,
			tvm,tvmin,tvmout, r1,v1;
    PIXTYPE		*objpix,*objpixt,*objweight,*objweightt, *lmodpix,
			pix, weight,var;
    int			x,y, x2,y2, pos, w,h, area, corrflag;


  corrflag = (prefs.mask_type==MASK_CORRECT);
  w = profit->objnaxisn[0];
  h = profit->objnaxisn[1];
  mx = (float)(w/2);
  my = (float)(h/2);
  if (FLAG(obj2.x_prof))
    {
    if (profit->paramlist[PARAM_X])
      mx += *profit->paramlist[PARAM_X];
    if (profit->paramlist[PARAM_Y])
      my += *profit->paramlist[PARAM_Y];
    }

  if (obj2->kronfactor>0.0)
    {
    cx2 = obj->cxx;
    cy2 = obj->cyy;
    cxy = obj->cxy;
    klim2 = 0.64*obj2->kronfactor*obj2->kronfactor;
    }
  else
/*-- ...if not, use the circular aperture provided by the user */
    {
    cx2 = cy2 = 1.0;
    cxy = 0.0;
    klim2 = (prefs.autoaper[1]/2.0)*(prefs.autoaper[1]/2.0);
    }
/*
  cx2 = obj2->prof_convcxx;
  cy2 = obj2->prof_convcyy;
  cxy = obj2->prof_convcxy;

  lmodpix = profit->lmodpix;
  r1 = v1 = 0.0;
  for (y=0; y<h; y++)
    {
    dy = y - my;
    for (x=0; x<w; x++)
      {
      dx = x - mx;
      pix = *(lmodpix++);
      r1 += sqrt(cx2*dx*dx + cy2*dy*dy + cxy*dx*dy)*pix;
      v1 += pix;
      }
    }

  klim = r1/v1*2.0;
  klim2 = klim*klim;

if ((check = prefs.check[CHECK_APERTURES]))
sexellips(check->pix, check->width, check->height,
obj2->x_prof-1.0, obj2->y_prof-1.0, klim*obj2->prof_conva,klim*obj2->prof_convb,
obj2->prof_convtheta, check->overlay, 0);
*/

  area = 0;
  tvmin = tvmout = tvobj = sigtvobj = 0.0;
  lmodpix = profit->lmodpix;
  objpixt = objpix = profit->objpix;
  objweightt = objweight = profit->objweight;
  for (y=0; y<h; y++)
    {
    for (x=0; x<w; x++, objpixt++,objweightt++)
      {
      dx = x - mx;
      dy = y - my;
      if ((cx2*dx*dx + cy2*dy*dy + cxy*dx*dy) <= klim2)
        {
        area++;
/*------ Here begin tests for pixel and/or weight overflows. Things are a */
/*------ bit intricated to have it running as fast as possible in the most */
/*------ common cases */
        if ((weight=*objweightt)<=0.0)
          {
          if (corrflag
		&& (x2=(int)(2*mx+0.49999-x))>=0 && x2<w
		&& (y2=(int)(2*my+0.49999-y))>=0 && y2<h
		&& (weight=objweight[pos = y2*w + x2])>0.0)
            {
            pix = objpix[pos];
            var = 1.0/(weight*weight);
            }
          else
            pix = var = 0.0;
          }
        else
          {
          pix = *objpixt;
          var = 1.0/(weight*weight);
          }
        tvobj += pix;
        sigtvobj += var;
        tvmin += *(lmodpix++);
//        *(lmodpix++) = pix;
        }
      else
        tvmout += *(lmodpix++);
      }
    }

//  tv -= area*bkg;

  tvm = tvmin + tvmout;
  if (tvm != 0.0)
    {
    obj2->fluxcor_prof = tvobj+obj2->flux_prof*tvmout/tvm;
    obj2->fluxcorerr_prof = sqrt(sigtvobj
			+obj2->fluxerr_prof*obj2->fluxerr_prof*tvmout/tvm);
    }
  else
    {
    obj2->fluxcor_prof = tvobj;
    obj2->fluxcorerr_prof = sqrt(sigtvobj);
    }

/*
  if ((check = prefs.check[CHECK_OTHER]))
    addcheck(check, profit->lmodpix, w, h, profit->ix,profit->iy, 1.0);
*/
  return;
  }


/****i* prof_gammainc *********************************************************
PROTO	double prof_gammainc(double x, double a)
PURPOSE	Returns the incomplete Gamma function (based on algorithm described in
	Numerical Recipes in C, chap. 6.1).
INPUT	A double,
	upper integration limit.
OUTPUT	Incomplete Gamma function.
NOTES	-.
AUTHOR	E. Bertin (IAP)
VERSION	08/10/2010
*/
static double	prof_gammainc (double x, double a)

  {
   double	b,c,d,h, xn,xp, del,sum;
   int		i;

  if (a < 0.0 || x <= 0.0)
    return 0.0;

  if (a < (x+1.0))
    {
/*-- Use the series representation */
    xp = x;
    del = sum = 1.0/x;
    for (i=100;i--;)	/* Iterate to convergence */
      {
      sum += (del *= a/(++xp));
      if (fabs(del) < fabs(sum)*3e-7)
        return sum*exp(-a+x*log(a)) / prof_gamma(x);
      }
    }
  else
    {
/*-- Use the continued fraction representation and take its complement */
    b = a + 1.0 - x;
    c = 1e30;
    h = d = 1.0/b;
    for (i=1; i<=100; i++)	/* Iterate to convergence */
      {
      xn = -i*(i-x);
      b += 2.0;
      if (fabs(d=xn*d+b) < 1e-30)
        d = 1e-30;
      if (fabs(c=b+xn/c) < 1e-30)
        c = 1e-30;
      del= c * (d = 1.0/d);
      h *= del;
      if (fabs(del-1.0) < 3e-7)
        return 1.0 - exp(-a+x*log(a))*h / prof_gamma(x);
      }
    }
  error(EXIT_FAILURE, "*Error*: out of bounds in ",
		"prof_gammainc()");
  return 0.0;
  }


/****i* prof_gamma ************************************************************
PROTO	double prof_gamma(double xx)
PURPOSE	Returns the Gamma function (based on algorithm described in Numerical
	Recipes in C, chap 6.1).
INPUT	A double.
OUTPUT	Gamma function.
NOTES	-.
AUTHOR	E. Bertin (IAP)
VERSION	11/09/2009
*/
static double	prof_gamma(double xx)

  {
   double		x,tmp,ser;
   static double	cof[6]={76.18009173,-86.50532033,24.01409822,
			-1.231739516,0.120858003e-2,-0.536382e-5};
   int			j;

  tmp=(x=xx-1.0)+5.5;
  tmp -= (x+0.5)*log(tmp);
  ser=1.0;
  for (j=0;j<6;j++)
    ser += cof[j]/(x+=1.0);

  return 2.50662827465*ser*exp(-tmp);
  }


/****** profit_minradius ******************************************************
PROTO	float profit_minradius(profitstruct *profit, float refffac)
PURPOSE	Returns the minimum disk radius that guarantees that each and
	every model component fits within some margin in that disk.
INPUT	Profit structure pointer,
	margin in units of (r/r_eff)^(1/n)).
OUTPUT	Radius (in pixels).
NOTES	-.
AUTHOR	E. Bertin (IAP)
VERSION	08/10/2010
*/
float	profit_minradius(profitstruct *profit, float refffac)

  {
   double	r,reff,rmax;
   int		p;

  rmax = reff = 0.0;
  for (p=0; p<profit->nprof; p++)
    {
    switch (profit->prof[p]->code)
      {
      case MODEL_BACK:
      case MODEL_DIRAC:
        reff = 0.0;
      break;
      case MODEL_SERSIC:
        reff = *profit->paramlist[PARAM_SPHEROID_REFF];
        break;
      case MODEL_DEVAUCOULEURS:
        reff = *profit->paramlist[PARAM_SPHEROID_REFF];
        break;
      case MODEL_EXPONENTIAL:
        reff = *profit->paramlist[PARAM_DISK_SCALE]*1.67835;
        break;
      default:
        error(EXIT_FAILURE, "*Internal Error*: Unknown profile parameter in ",
		"profit_minradius()");
        break;
      }
    r = reff*(double)refffac;
    if (r>rmax)
      rmax = r;
    }

  return (float)rmax;
  }


/****** profit_psf ************************************************************
PROTO	void	profit_psf(profitstruct *profit)
PURPOSE	Build the local PSF at a given resolution.
INPUT	Profile-fitting structure.
OUTPUT	-.
NOTES	-.
AUTHOR	E. Bertin (IAP)
VERSION	07/07/2010
 ***/
void	profit_psf(profitstruct *profit)
  {
   double	flux;
   float	posin[2], posout[2], dnaxisn[2],
		*pixout,
		xcout,ycout, xcin,ycin, invpixstep, norm;
   int		d,i;

  psf = profit->psf;
  psf_build(psf);

  xcout = (float)(profit->modnaxisn[0]/2) + 1.0;	/* FITS convention */
  ycout = (float)(profit->modnaxisn[1]/2) + 1.0;	/* FITS convention */
  xcin = (psf->masksize[0]/2) + 1.0;			/* FITS convention */
  ycin = (psf->masksize[1]/2) + 1.0;			/* FITS convention */
  invpixstep = profit->pixstep / psf->pixstep;

/* Initialize multi-dimensional counters */
  for (d=0; d<2; d++)
    {
    posout[d] = 1.0;					/* FITS convention */
    dnaxisn[d] = profit->modnaxisn[d]+0.5;
    }

/* Remap each pixel */
  pixout = profit->psfpix;
  flux = 0.0;
  for (i=profit->modnaxisn[0]*profit->modnaxisn[1]; i--;)
    {
    posin[0] = (posout[0] - xcout)*invpixstep + xcin;
    posin[1] = (posout[1] - ycout)*invpixstep + ycin;
    flux += ((*(pixout++) = interpolate_pix(posin, psf->maskloc,
		psf->masksize, INTERP_LANCZOS3)));
    for (d=0; d<2; d++)
      if ((posout[d]+=1.0) < dnaxisn[d])
        break;
      else
        posout[d] = 1.0;
    }

/* Normalize PSF flux (just in case...) */
  flux *= profit->pixstep*profit->pixstep;
  if (fabs(flux) <= 0.0)
    error(EXIT_FAILURE, "*Error*: PSF model is empty or negative: ", psf->name);

  norm = 1.0/flux;
  pixout = profit->psfpix;
  for (i=profit->modnaxisn[0]*profit->modnaxisn[1]; i--;)
    *(pixout++) *= norm;  

  return;
  }


/****** profit_minimize *******************************************************
PROTO	void profit_minimize(profitstruct *profit)
PURPOSE	Provide a function returning residuals to lmfit.
INPUT	Pointer to the profit structure involved in the fit,
	maximum number of iterations.
OUTPUT	Number of iterations used.
NOTES	-.
AUTHOR	E. Bertin (IAP)
VERSION	20/05/2011
 ***/
int	profit_minimize(profitstruct *profit, int niter)
  {
   double	lm_opts[5], info[LM_INFO_SZ],
		dcovar[PARAM_NPARAM*PARAM_NPARAM], dparam[PARAM_NPARAM];
   int		nfree;

  profit->iter = 0;
  memset(dcovar, 0, profit->nparam*profit->nparam*sizeof(double));

/* Perform fit */
  lm_opts[0] = 1.0e-3;		/* Initial mu */
  lm_opts[1] = 1.0e-6;		/* ||J^T e||_inf stopping factor */
  lm_opts[2] = 1.0e-6;		/* |Dp||_2 stopping factor */
  lm_opts[3] = 1.0e-6;		/* ||e||_2 stopping factor */
  lm_opts[4] = 1.0e-4;		/* Jacobian step */

  nfree = profit_boundtounbound(profit, profit->paraminit, dparam,
				PARAM_ALLPARAMS);

  niter = dlevmar_dif(profit_evaluate, dparam, NULL, nfree, profit->nresi,
			niter, lm_opts, info, NULL, dcovar, profit);

  profit_unboundtobound(profit, dparam, profit->paraminit, PARAM_ALLPARAMS);

/* Convert covariance matrix to bounded space */
  profit_covarunboundtobound(profit, dcovar, profit->covar);

  return niter;
  }


/****** profit_printout *******************************************************
PROTO	void profit_printout(int n_par, float* par, int m_dat, float* fvec,
		void *data, int iflag, int iter, int nfev )
PURPOSE	Provide a function to print out results to lmfit.
INPUT	Number of fitted parameters,
	pointer to the vector of parameters,
	number of data points,
	pointer to the vector of residuals (output),
	pointer to the data structure (unused),
	0 (init) 1 (outer loop) 2(inner loop) -1(terminated),
	outer loop counter,
	number of calls to evaluate().
OUTPUT	-.
NOTES	Input arguments are there only for compatibility purposes (unused)
AUTHOR	E. Bertin (IAP)
VERSION	17/09/2008
 ***/
void	profit_printout(int n_par, float* par, int m_dat, float* fvec,
		void *data, int iflag, int iter, int nfev )
  {
   checkstruct	*check;
   profitstruct	*profit;
   char		filename[256];
   static int	itero;

  profit = (profitstruct *)data;

  if (0 && (iter!=itero || iter<0))
    {
    if (iter<0)
      itero++;
    else
      itero = iter;
    sprintf(filename, "check_%d_%04d.fits", the_gal, itero);
    check=initcheck(filename, CHECK_PROFILES, 0);
    reinitcheck(the_field, check);
    addcheck(check, profit->lmodpix, profit->objnaxisn[0],profit->objnaxisn[1],
		profit->ix,profit->iy, 1.0);

    reendcheck(the_field, check);
    endcheck(check);
    }

  return;
  }


/****** profit_evaluate ******************************************************
PROTO	void profit_evaluate(double *par, double *fvec, int m, int n,
			void *adata)
PURPOSE	Provide a function returning residuals to levmar.
INPUT	Pointer to the vector of parameters,
	pointer to the vector of residuals (output),
	number of model parameters,
	number of data points,
	pointer to a data structure (we use it for the profit structure here).
OUTPUT	-.
NOTES	-.
AUTHOR	E. Bertin (IAP)
VERSION	20/05/2011
 ***/
void	profit_evaluate(double *dpar, double *fvec, int m, int n, void *adata)
  {
   profitstruct		*profit;
   profstruct		**prof;
   double		*dpar0, *dresi;
   float		*modpixt, *profpixt, *resi,
			tparam, val;
   PIXTYPE		*lmodpixt,*lmodpix2t, *objpix,*weight,
			wval;
   int			c,f,i,p,q, fd,pd, jflag,sflag, nprof;

  profit = (profitstruct *)adata;

/* Detect "Jacobian-related" calls */
  jflag = pd = fd = 0;
  dpar0 = profit->dparam;
  if (profit->iter)
    {
    f = q = 0;
    for (p=0; p<profit->nparam; p++)
      {
      if (dpar[f] - dpar0[f] != 0.0)
        {
        pd = p;
        fd = f;
        q++;
        }
      if (profit->parfittype[p]!=PARFIT_FIXED)
        f++;
      }
    if (f>0 && q==1)
      jflag = 1;
    }
jflag = 0;	/* Temporarily deactivated (until problems are fixed) */
  if (jflag && !(profit->nprof==1 && profit->prof[0]->code == MODEL_DIRAC))
    {
    prof = profit->prof;
    nprof = profit->nprof;

/*-- "Jacobian call" */
    tparam = profit->param[pd];
    profit_unboundtobound(profit, &dpar[fd], &profit->param[pd], pd);
    sflag = 1;
    switch(profit->paramrevindex[pd])
      {
      case PARAM_BACK:
        lmodpixt = profit->lmodpix;
        lmodpix2t = profit->lmodpix2;
        val = (profit->param[pd] - tparam);
        for (i=profit->nobjpix;i--;)
          *(lmodpix2t++) = val;
        break;
      case PARAM_X:
      case PARAM_Y:
        profit_resample(profit, profit->cmodpix, profit->lmodpix2, 1.0);
        lmodpixt = profit->lmodpix;
        lmodpix2t = profit->lmodpix2;
        for (i=profit->nobjpix;i--;)
          *(lmodpix2t++) -= *(lmodpixt++);
        break;
      case PARAM_DIRAC_FLUX:
      case PARAM_SPHEROID_FLUX:
      case PARAM_DISK_FLUX:
      case PARAM_ARMS_FLUX:
      case PARAM_BAR_FLUX:
        if (nprof==1 && tparam != 0.0)
          {
          lmodpixt = profit->lmodpix;
          lmodpix2t = profit->lmodpix2;
          val = (profit->param[pd] - tparam) / tparam;
          for (i=profit->nobjpix;i--;)
            *(lmodpix2t++) = val**(lmodpixt++);
          }
        else
          {
          for (c=0; c<nprof; c++)
            if (prof[c]->flux == &profit->param[pd])
              break;
          memcpy(profit->modpix, prof[c]->pix, profit->nmodpix*sizeof(float));
          profit_convolve(profit, profit->modpix);
          profit_resample(profit, profit->modpix, profit->lmodpix2,
		profit->param[pd] - tparam);
          }
        break;
      case PARAM_SPHEROID_REFF:
      case PARAM_SPHEROID_ASPECT:
      case PARAM_SPHEROID_POSANG:
      case PARAM_SPHEROID_SERSICN:
        sflag = 0;			/* We are in the same switch */
        for (c=0; c<nprof; c++)
          if (prof[c]->code == MODEL_SERSIC
		|| prof[c]->code == MODEL_DEVAUCOULEURS)
            break; 
      case PARAM_DISK_SCALE:
      case PARAM_DISK_ASPECT:
      case PARAM_DISK_POSANG:
        if (sflag)
          for (c=0; c<nprof; c++)
            if (prof[c]->code == MODEL_EXPONENTIAL)
              break; 
        sflag = 0;
      case PARAM_ARMS_QUADFRAC:
      case PARAM_ARMS_SCALE:
      case PARAM_ARMS_START:
      case PARAM_ARMS_POSANG:
      case PARAM_ARMS_PITCH:
      case PARAM_ARMS_PITCHVAR:
      case PARAM_ARMS_WIDTH:
        if (sflag)
          for (c=0; c<nprof; c++)
            if (prof[c]->code == MODEL_ARMS)
              break; 
        sflag = 0;
      case PARAM_BAR_ASPECT:
      case PARAM_BAR_POSANG:
        if (sflag)
          for (c=0; c<nprof; c++)
            if (prof[c]->code == MODEL_ARMS)
              break; 
        modpixt = profit->modpix;
        profpixt = prof[c]->pix;
        val = -*prof[c]->flux;
        for (i=profit->nmodpix;i--;)
          *(modpixt++) = val**(profpixt++);
        memcpy(profit->modpix2, prof[c]->pix, profit->nmodpix*sizeof(float));
        prof_add(profit, prof[c], 0);
        memcpy(prof[c]->pix, profit->modpix2, profit->nmodpix*sizeof(float));
        profit_convolve(profit, profit->modpix);
        profit_resample(profit, profit->modpix, profit->lmodpix2, 1.0);
        break;
      default:
        error(EXIT_FAILURE, "*Internal Error*: ",
			"unknown parameter index in profit_jacobian()");
        break;
      }
    objpix = profit->objpix;
    weight = profit->objweight;
    lmodpixt = profit->lmodpix;
    lmodpix2t = profit->lmodpix2;
    resi = profit->resi;
    dresi = fvec;
    if (PROFIT_DYNPARAM > 0.0)
      for (i=profit->nobjpix;i--; lmodpixt++, lmodpix2t++)
        {
        val = *(objpix++);
        if ((wval=*(weight++))>0.0)
          *(dresi++) = *(resi++) + *lmodpix2t
		* wval/(1.0+wval*fabs(*lmodpixt - val)/PROFIT_DYNPARAM);
        }
    else
      for (i=profit->nobjpix;i--; lmodpix2t++)
        if ((wval=*(weight++))>0.0)
          *(dresi++) = *(resi++) + *lmodpix2t * wval;
    }
  else
    {
/*-- "Regular call" */
    for (p=0; p<profit->nparam; p++)
      dpar0[p] = dpar[p];
    profit_unboundtobound(profit, dpar, profit->param, PARAM_ALLPARAMS);

    profit_residuals(profit, the_field, the_wfield, PROFIT_DYNPARAM,
	profit->param, profit->resi);

    for (p=0; p<profit->nresi; p++)
      fvec[p] = profit->resi[p];
    }

//  profit_printout(m, par, n, fvec, adata, 0, -1, 0 );
  profit->iter++;

  return;
  }


/****** profit_residuals ******************************************************
PROTO	float *prof_residuals(profitstruct *profit, picstruct *field,
		picstruct *wfield, float dynparam, float *param, float *resi)
PURPOSE	Compute the vector of residuals between the data and the galaxy
	profile model.
INPUT	Profile-fitting structure,
	pointer to the field,
	pointer to the field weight,
	dynamic compression parameter (0=no compression),
	pointer to the model parameters (output),
	pointer to the computed residuals (output).
OUTPUT	Vector of residuals.
NOTES	-.
AUTHOR	E. Bertin (IAP)
VERSION	08/07/2010
 ***/
float	*profit_residuals(profitstruct *profit, picstruct *field,
		picstruct *wfield, float dynparam, float *param, float *resi)
  {
   int		p, nmodpix;

  nmodpix = profit->modnaxisn[0]*profit->modnaxisn[1]*sizeof(float);
  memset(profit->modpix, 0, nmodpix);
  for (p=0; p<profit->nparam; p++)
    profit->param[p] = param[p];
/* Simple PSF shortcut */
  if (profit->nprof == 1 && profit->prof[0]->code == MODEL_DIRAC)
    {
    profit_resample(profit, profit->psfpix, profit->lmodpix,
		*profit->prof[0]->flux);
    profit->flux = *profit->prof[0]->flux;
    }
  else
    {
    profit->flux = 0.0;
    for (p=0; p<profit->nprof; p++)
      profit->flux += prof_add(profit, profit->prof[p], 0);
    memcpy(profit->cmodpix, profit->modpix, profit->nmodpix*sizeof(float));
    profit_convolve(profit, profit->cmodpix);
    profit_resample(profit, profit->cmodpix, profit->lmodpix, 1.0);
    }

  if (resi)
    profit_compresi(profit, dynparam, resi);

  return resi;
  }


/****** profit_compresi ******************************************************
PROTO	float *profit_compresi(profitstruct *profit, float dynparam,
			float *resi)
PURPOSE	Compute the vector of residuals between the data and the galaxy
	profile model.
INPUT	Profile-fitting structure,
	dynamic-compression parameter (0=no compression),
	vector of residuals (output).
OUTPUT	Vector of residuals.
NOTES	-.
AUTHOR	E. Bertin (IAP)
VERSION	07/09/2009
 ***/
float	*profit_compresi(profitstruct *profit, float dynparam, float *resi)
  {
   double	error;
   float	*resit;
   PIXTYPE	*objpix, *objweight, *lmodpix,
		val,val2,wval, invsig;
   int		npix, i;
  
/* Compute vector of residuals */
  resit = resi;
  objpix = profit->objpix;
  objweight = profit->objweight;
  lmodpix = profit->lmodpix;
  error = 0.0;
  npix = profit->objnaxisn[0]*profit->objnaxisn[1];
  if (dynparam > 0.0)
    {
    invsig = (PIXTYPE)(1.0/dynparam);
    for (i=npix; i--; lmodpix++)
      {
      val = *(objpix++);
      if ((wval=*(objweight++))>0.0)
        {
        val2 = (*lmodpix - val)*wval*invsig;
        val2 = val2>0.0? logf(1.0+val2) : -logf(1.0-val2);
        *(resit++) = val2*dynparam;
        error += val2*val2;
        }
      }
    profit->chi2 = dynparam*dynparam*error;
    }
  else
    {
    for (i=npix; i--; lmodpix++)
      {
      val = *(objpix++);
      if ((wval=*(objweight++))>0.0)
        {
        val2 = (*lmodpix - val)*wval;
        *(resit++) = val2;
        error += val2*val2;
        }
      }
    profit->chi2 = error;
    }

  return resi;
  }


/****** profit_resample ******************************************************
PROTO	int	prof_resample(profitstruct *profit, float *inpix,
		PIXTYPE *outpix, float factor)
PURPOSE	Resample the current full resolution model to image resolution.
INPUT	Profile-fitting structure,
	pointer to input raster,
	pointer to output raster,
	multiplicating factor.
OUTPUT	RETURN_ERROR if the rasters don't overlap, RETURN_OK otherwise.
NOTES	-.
AUTHOR	E. Bertin (IAP)
VERSION	12/09/2010
 ***/
int	profit_resample(profitstruct *profit, float *inpix, PIXTYPE *outpix,
	float factor)
  {
   PIXTYPE	*pixout,*pixout0;
   float	*pixin,*pixin0, *mask,*maskt, *pixinout, *dpixin,*dpixin0,
		*dpixout,*dpixout0, *dx,*dy,
		xcin,xcout,ycin,ycout, xsin,ysin, xin,yin, x,y, dxm,dym, val,
		invpixstep, norm;
   int		*start,*startt, *nmask,*nmaskt,
		i,j,k,n,t, 
		ixsout,iysout, ixout,iyout, dixout,diyout, nxout,nyout,
		iysina, nyin, hmw,hmh, ix,iy, ixin,iyin;

  invpixstep = profit->subsamp/profit->pixstep;

  xcin = (profit->modnaxisn[0]/2);
  xcout = (float)(profit->objnaxisn[0]/2);
  if ((dx=(profit->paramlist[PARAM_X])))
    xcout += *dx;

  xsin = xcin - xcout*invpixstep;			/* Input start x-coord*/
  if ((int)xsin >= profit->modnaxisn[0])
    return RETURN_ERROR;
  ixsout = 0;				/* Int. part of output start x-coord */
  if (xsin<0.0)
    {
    dixout = (int)(1.0-xsin/invpixstep);
/*-- Simply leave here if the images do not overlap in x */
    if (dixout >= profit->objnaxisn[0])
      return RETURN_ERROR;
    ixsout += dixout;
    xsin += dixout*invpixstep;
    }
  nxout = (int)((profit->modnaxisn[0]-xsin)/invpixstep);/* nb of interpolated
							input pixels along x */
  if (nxout>(ixout=profit->objnaxisn[0]-ixsout))
    nxout = ixout;
  if (!nxout)
    return RETURN_ERROR;

  ycin = (profit->modnaxisn[1]/2);
  ycout = (float)(profit->objnaxisn[1]/2);
  if ((dy=(profit->paramlist[PARAM_Y])))
    ycout += *dy;

  ysin = ycin - ycout*invpixstep;		/* Input start y-coord*/
  if ((int)ysin >= profit->modnaxisn[1])
    return RETURN_ERROR;
  iysout = 0;				/* Int. part of output start y-coord */
  if (ysin<0.0)
    {
    diyout = (int)(1.0-ysin/invpixstep);
/*-- Simply leave here if the images do not overlap in y */
    if (diyout >= profit->objnaxisn[1])
      return RETURN_ERROR;
    iysout += diyout;
    ysin += diyout*invpixstep;
    }
  nyout = (int)((profit->modnaxisn[1]-ysin)/invpixstep);/* nb of interpolated
							input pixels along y */
  if (nyout>(iyout=profit->objnaxisn[1]-iysout))
    nyout = iyout;
  if (!nyout)
    return RETURN_ERROR;

/* Set the yrange for the x-resampling with some margin for interpolation */
  iysina = (int)ysin;	/* Int. part of Input start y-coord with margin */
  hmh = INTERPW/2 - 1;	/* Interpolant start */
  if (iysina<0 || ((iysina -= hmh)< 0))
    iysina = 0;
  nyin = (int)(ysin+nyout*invpixstep)+INTERPW-hmh;/* Interpolated Input y size*/
  if (nyin>profit->modnaxisn[1])						/* with margin */
    nyin = profit->modnaxisn[1];
/* Express everything relative to the effective Input start (with margin) */
  nyin -= iysina;
  ysin -= (float)iysina;

/* Allocate interpolant stuff for the x direction */
  QMALLOC(mask, float, nxout*INTERPW);	/* Interpolation masks */
  QMALLOC(nmask, int, nxout);		/* Interpolation mask sizes */
  QMALLOC(start, int, nxout);		/* Int. part of Input conv starts */
/* Compute the local interpolant and data starting points in x */
  hmw = INTERPW/2 - 1;
  xin = xsin;
  maskt = mask;
  nmaskt = nmask;
  startt = start;
  for (j=nxout; j--; xin+=invpixstep)
    {
    ix = (ixin=(int)xin) - hmw;
    dxm = ixin - xin - hmw;	/* starting point in the interpolation func */
    if (ix < 0)
      {
      n = INTERPW+ix;
      dxm -= (float)ix;
      ix = 0;
      }
    else
      n = INTERPW;
    if (n>(t=profit->modnaxisn[0]-ix))
      n=t;
    *(startt++) = ix;
    *(nmaskt++) = n;
    norm = 0.0;
    for (x=dxm, i=n; i--; x+=1.0)
      norm += (*(maskt++) = INTERPF(x));
    norm = norm>0.0? 1.0/norm : 1.0;
    maskt -= n;
    for (i=n; i--;)
      *(maskt++) *= norm;
    }

  QCALLOC(pixinout, float, nxout*nyin);	/* Intermediary frame-buffer */

/* Make the interpolation in x (this includes transposition) */
  pixin0 = inpix + iysina*profit->modnaxisn[0];
  dpixout0 = pixinout;
  for (k=nyin; k--; pixin0+=profit->modnaxisn[0], dpixout0++)
    {
    maskt = mask;
    nmaskt = nmask;
    startt = start;
    dpixout = dpixout0;
    for (j=nxout; j--; dpixout+=nyin)
      {
      pixin = pixin0+*(startt++);
      val = 0.0; 
      for (i=*(nmaskt++); i--;)
        val += *(maskt++)**(pixin++);
      *dpixout = val;
      }
    }

/* Reallocate interpolant stuff for the y direction */
  QREALLOC(mask, float, nyout*INTERPW);	/* Interpolation masks */
  QREALLOC(nmask, int, nyout);			/* Interpolation mask sizes */
  QREALLOC(start, int, nyout);		/* Int. part of Input conv starts */

/* Compute the local interpolant and data starting points in y */
  hmh = INTERPW/2 - 1;
  yin = ysin;
  maskt = mask;
  nmaskt = nmask;
  startt = start;
  for (j=nyout; j--; yin+=invpixstep)
    {
    iy = (iyin=(int)yin) - hmh;
    dym = iyin - yin - hmh;	/* starting point in the interpolation func */
    if (iy < 0)
      {
      n = INTERPW+iy;
      dym -= (float)iy;
      iy = 0;
      }
    else
      n = INTERPW;
    if (n>(t=nyin-iy))
      n=t;
    *(startt++) = iy;
    *(nmaskt++) = n;
    norm = 0.0;
    for (y=dym, i=n; i--; y+=1.0)
      norm += (*(maskt++) = INTERPF(y));
    norm = norm>0.0? 1.0/norm : 1.0;
    maskt -= n;
    for (i=n; i--;)
      *(maskt++) *= norm;
    }