profit.c

      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;
    }

/* Initialize destination buffer to zero */
  memset(outpix, 0, (size_t)profit->nobjpix*sizeof(PIXTYPE));

/* Make the interpolation in y and transpose once again */
  dpixin0 = pixinout;
  pixout0 = outpix+ixsout+iysout*profit->objnaxisn[0];
  for (k=nxout; k--; dpixin0+=nyin, pixout0++)
    {
    maskt = mask;
    nmaskt = nmask;
    startt = start;
    pixout = pixout0;
    for (j=nyout; j--; pixout+=profit->objnaxisn[0])
      {
      dpixin = dpixin0+*(startt++);
      val = 0.0; 
      for (i=*(nmaskt++); i--;)
        val += *(maskt++)**(dpixin++);
       *pixout = (PIXTYPE)(factor*val);
      }
    }

/* Free memory */
  free(pixinout);
  free(mask);
  free(nmask);
  free(start);

  return RETURN_OK;
  }


/****** profit_convolve *******************************************************
PROTO	void profit_convolve(profitstruct *profit, float *modpix)
PURPOSE	Convolve a model image with the local PSF.
INPUT	Pointer to the profit structure,
	Pointer to the image raster.
OUTPUT	-.
NOTES	-.
AUTHOR	E. Bertin (IAP)
VERSION	15/09/2008
 ***/
void	profit_convolve(profitstruct *profit, float *modpix)
  {
  if (!profit->psfdft)
    profit_makedft(profit);

  fft_conv(modpix, profit->psfdft, profit->modnaxisn);

  return;
  }


/****** profit_makedft *******************************************************
PROTO	void profit_makedft(profitstruct *profit)
PURPOSE	Create the Fourier transform of the descrambled PSF component.
INPUT	Pointer to the profit structure.
OUTPUT	-.
NOTES	-.
AUTHOR	E. Bertin (IAP)
VERSION	22/04/2008
 ***/
void	profit_makedft(profitstruct *profit)
  {
   psfstruct	*psf;
   float      *mask,*maskt, *ppix;
   float       dx,dy, r,r2,rmin,rmin2,rmax,rmax2,rsig,invrsig2;
   int          width,height,npix,offset, psfwidth,psfheight,psfnpix,
                cpwidth, cpheight,hcpwidth,hcpheight, i,j,x,y;

  if (!(psf=profit->psf))
    return;

  psfwidth = profit->modnaxisn[0];
  psfheight = profit->modnaxisn[1];
  psfnpix = psfwidth*psfheight;
  width = profit->modnaxisn[0];
  height = profit->modnaxisn[1];
  npix = width*height;
  QCALLOC(mask, float, npix);
  cpwidth = (width>psfwidth)?psfwidth:width;
  hcpwidth = cpwidth>>1;
  cpwidth = hcpwidth<<1;
  offset = width - cpwidth;
  cpheight = (height>psfheight)?psfheight:height;
  hcpheight = cpheight>>1;
  cpheight = hcpheight<<1;

/* Frame and descramble the PSF data */
  ppix = profit->psfpix + (psfheight/2)*psfwidth + psfwidth/2;
  maskt = mask;
  for (j=hcpheight; j--; ppix+=psfwidth)
    {
    for (i=hcpwidth; i--;)
      *(maskt++) = *(ppix++);      
    ppix -= cpwidth;
    maskt += offset;
    for (i=hcpwidth; i--;)
      *(maskt++) = *(ppix++);      
    }

  ppix = profit->psfpix + ((psfheight/2)-hcpheight)*psfwidth + psfwidth/2;
  maskt += width*(height-cpheight);
  for (j=hcpheight; j--; ppix+=psfwidth)
    {
    for (i=hcpwidth; i--;)
      *(maskt++) = *(ppix++);      
    ppix -= cpwidth;
    maskt += offset;
    for (i=hcpwidth; i--;)
      *(maskt++) = *(ppix++);      
    }

/* Truncate to a disk that has diameter = (box width) */
  rmax = cpwidth - 1.0 - hcpwidth;
  if (rmax > (r=hcpwidth))
    rmax = r;
  if (rmax > (r=cpheight-1.0-hcpheight))
    rmax = r;
  if (rmax > (r=hcpheight))
    rmax = r;
  if (rmax<1.0)
    rmax = 1.0;
  rmax2 = rmax*rmax;
  rsig = psf->fwhm/profit->pixstep;
  invrsig2 = 1/(2*rsig*rsig);
  rmin = rmax - (3*rsig);     /* 3 sigma annulus (almost no aliasing) */
  rmin2 = rmin*rmin;

  maskt = mask;
  dy = 0.0;
  for (y=hcpheight; y--; dy+=1.0)
    {
    dx = 0.0;
    for (x=hcpwidth; x--; dx+=1.0, maskt++)
      if ((r2=dx*dx+dy*dy)>rmin2)
        *maskt *= (r2>rmax2)?0.0:expf((2*rmin*sqrtf(r2)-r2-rmin2)*invrsig2);
    dx = -hcpwidth;
    maskt += offset;
    for (x=hcpwidth; x--; dx+=1.0, maskt++)
      if ((r2=dx*dx+dy*dy)>rmin2)
        *maskt *= (r2>rmax2)?0.0:expf((2*rmin*sqrtf(r2)-r2-rmin2)*invrsig2);
    }
  dy = -hcpheight;
  maskt += width*(height-cpheight);
  for (y=hcpheight; y--; dy+=1.0)
    {
    dx = 0.0;
    for (x=hcpwidth; x--; dx+=1.0, maskt++)
      if ((r2=dx*dx+dy*dy)>rmin2)
        *maskt *= (r2>rmax2)?0.0:expf((2*rmin*sqrtf(r2)-r2-rmin2)*invrsig2);
    dx = -hcpwidth;
    maskt += offset;
    for (x=hcpwidth; x--; dx+=1.0, maskt++)
      if ((r2=dx*dx+dy*dy)>rmin2)
        *maskt *= (r2>rmax2)?0.0:expf((2*rmin*sqrtf(r2)-r2-rmin2)*invrsig2);
    }

/* Finally move to Fourier space */
  profit->psfdft = fft_rtf(mask, profit->modnaxisn);

  free(mask);

  return;
  }


/****** profit_copyobjpix *****************************************************
PROTO	int profit_copyobjpix(profitstruct *profit, picstruct *field,
			picstruct *wfield)
PURPOSE	Copy a piece of the input field image to a profit structure.
INPUT	Pointer to the profit structure,
	Pointer to the field structure,
	Pointer to the field weight structure.
OUTPUT	The number of valid pixels copied.
NOTES	Global preferences are used.
AUTHOR	E. Bertin (IAP)
VERSION	01/12/2009
 ***/
int	profit_copyobjpix(profitstruct *profit, picstruct *field,
			picstruct *wfield)
  {
   float	dx, dy2, dr2, rad2;
   PIXTYPE	*pixin,*spixin, *wpixin,*swpixin, *pixout,*wpixout,
		backnoise2, invgain, satlevel, wthresh, pix,spix, wpix,swpix;
   int		i,x,y, xmin,xmax,ymin,ymax, w,h,dw, npix, off, gainflag,
		badflag, sflag, sx,sy,sn,sw, ix,iy;

/* First put the image background to -BIG */
  pixout = profit->objpix;
  wpixout = profit->objweight;
  for (i=profit->objnaxisn[0]*profit->objnaxisn[1]; i--;)
    {
    *(pixout++) = -BIG;
    *(wpixout++) = 0.0;
    }

/* Don't go further if out of frame!! */
  ix = profit->ix;
  iy = profit->iy;
  if (ix<0 || ix>=field->width || iy<field->ymin || iy>=field->ymax)
    return 0;

  backnoise2 = field->backsig*field->backsig;
  sn = (int)profit->subsamp;
  sflag = (sn>1);
  w = profit->objnaxisn[0]*sn;
  h = profit->objnaxisn[1]*sn;
  if (sflag)
    backnoise2 *= (PIXTYPE)sn;
  invgain = (field->gain > 0.0) ? 1.0/field->gain : 0.0;
  satlevel = field->satur_level - profit->obj->bkg;
  rad2 = h/2.0;
  if (rad2 > w/2.0)
    rad2 = w/2.0;
  rad2 *= rad2;

/* Set the image boundaries */
  pixout = profit->objpix;
  wpixout = profit->objweight;
  ymin = iy-h/2;
  ymax = ymin + h;
  if (ymin<field->ymin)
    {
    off = (field->ymin-ymin-1)/sn + 1;
    pixout += off*profit->objnaxisn[0];
    wpixout += off*profit->objnaxisn[0];
    ymin += off*sn;
    }
  if (ymax>field->ymax)
    ymax -= ((ymax-field->ymax-1)/sn + 1)*sn;

  xmin = ix-w/2;
  xmax = xmin + w;
  dw = 0;
  if (xmax>field->width)
    {
    off = (xmax-field->width-1)/sn + 1;
    dw += off;
    xmax -= off*sn;
    }
  if (xmin<0)
    {
    off = (-xmin-1)/sn + 1;
    pixout += off;
    wpixout += off;
    dw += off;
    xmin += off*sn;
    }
/* Make sure the input frame size is a multiple of the subsampling step */
  if (sflag)
    {
/*
    if (((rem=ymax-ymin)%sn))
      {
      ymin += rem/2;
      ymax -= (rem-rem/2);
      }
    if (((rem=xmax-xmin)%sn))
      {
      xmin += rem/2;
      pixout += rem/2;
      wpixout += rem/2;
      dw += rem;
      xmax -= (rem-rem/2);
      }
*/
    sw = field->width;
    }

/* Copy the right pixels to the destination */
  npix = 0;
  if (wfield)
    {
    wthresh = wfield->weight_thresh;
    gainflag = prefs.weightgain_flag;
    if (sflag)
      {
/*---- Sub-sampling case */
      for (y=ymin; y<ymax; y+=sn, pixout+=dw,wpixout+=dw)
        {
        for (x=xmin; x<xmax; x+=sn)
          {
          pix = wpix = 0.0;
          badflag = 0;
          for (sy=0; sy<sn; sy++)
            {
            dy2 = (y+sy-iy);
            dy2 *= dy2;
            dx = (x-ix);
            spixin = &PIX(field, x, y+sy);
            swpixin = &PIX(wfield, x, y+sy);
            for (sx=sn; sx--;)
              {
              dr2 = dy2 + dx*dx;
              dx++;
              spix = *(spixin++);
              swpix = *(swpixin++);
              if (dr2<rad2 && spix>-BIG && spix<satlevel && swpix<wthresh)
                {
                pix += spix;
                wpix += swpix;
                }
              else
                badflag=1;
              }
            }
          *(pixout++) = pix;
          if (!badflag)	/* A single bad pixel ruins is all (saturation, etc.)*/
            {
            *(wpixout++) = 1.0 / sqrt(wpix+(pix>0.0?
		(gainflag? pix*wpix/backnoise2:pix)*invgain : 0.0));
            npix++;
            }
          else
            *(wpixout++) = 0.0;
          }
        }
      }
    else
      for (y=ymin; y<ymax; y++, pixout+=dw,wpixout+=dw)
        {
        dy2 = y-iy;
        dy2 *= dy2;
        pixin = &PIX(field, xmin, y);
        wpixin = &PIX(wfield, xmin, y);
        for (x=xmin; x<xmax; x++)
          {
          dx = x-ix;
          dr2 = dy2 + dx*dx;
          pix = *(pixin++);
          wpix = *(wpixin++);
          if (dr2<rad2 && pix>-BIG && pix<satlevel && wpix<wthresh)
            {
            *(pixout++) = pix;
            *(wpixout++) = 1.0 / sqrt(wpix+(pix>0.0?
		(gainflag? pix*wpix/backnoise2:pix)*invgain : 0.0));
            npix++;
            }
          else
            *(pixout++) = *(wpixout++) = 0.0;
          }
        }
    }
  else
    {
    if (sflag)
      {
/*---- Sub-sampling case */
      for (y=ymin; y<ymax; y+=sn, pixout+=dw, wpixout+=dw)
        {
        for (x=xmin; x<xmax; x+=sn)
          {
          pix = 0.0;
          badflag = 0;
          for (sy=0; sy<sn; sy++)
            {
            dy2 = y+sy-iy;
            dy2 *= dy2;
            dx = x-ix;
            spixin = &PIX(field, x, y+sy);
            for (sx=sn; sx--;)
              {
              dr2 = dy2 + dx*dx;
              dx++;
              spix = *(spixin++);
              if (dr2<rad2 && spix>-BIG && spix<satlevel)
                pix += spix;
              else
                badflag=1;
              }
            }
          *(pixout++) = pix;
          if (!badflag)	/* A single bad pixel ruins is all (saturation, etc.)*/
            {
            *(wpixout++) = 1.0 / sqrt(backnoise2 + (pix>0.0?pix*invgain:0.0));
            npix++;
            }
          else
            *(wpixout++) = 0.0;
          }
        }
      }
    else
      for (y=ymin; y<ymax; y++, pixout+=dw,wpixout+=dw)
        {
        dy2 = y-iy;
        dy2 *= dy2;
        pixin = &PIX(field, xmin, y);
        for (x=xmin; x<xmax; x++)
          {
          dx = x-ix;
          dr2 = dy2 + dx*dx;
          pix = *(pixin++);
          if (dr2<rad2 && pix>-BIG && pix<satlevel)
            {
            *(pixout++) = pix;
            *(wpixout++) = 1.0 / sqrt(backnoise2 + (pix>0.0?pix*invgain : 0.0));
            npix++;
            }
          else
            *(pixout++) = *(wpixout++) = 0.0;
          }
        }
    }
 
  return npix;
  }


/****** profit_spiralindex ****************************************************
PROTO	float profit_spiralindex(profitstruct *profit)
PURPOSE	Compute the spiral index of a galaxy image (positive for arms
	extending counter-clockwise and negative for arms extending CW, 0 for
	no spiral pattern).
INPUT	Profile-fitting structure.
OUTPUT	Vector of residuals.
NOTES	-.
AUTHOR	E. Bertin (IAP)
VERSION	12/07/2012
 ***/
float profit_spiralindex(profitstruct *profit)
  {
   objstruct	*obj;
   obj2struct	*obj2;
   float	*dx,*dy, *fdx,*fdy, *gdx,*gdy, *gdxt,*gdyt, *pix,
		fwhm, invtwosigma2, hw,hh, ohw,ohh, x,y,xstart, tx,ty,txstart,
		gx,gy, r2, spirindex, invsig, val, sep;
   PIXTYPE	*fpix;
   int		i,j, npix;

  npix = profit->objnaxisn[0]*profit->objnaxisn[1];

  obj = profit->obj;
  obj2 = profit->obj2;
/* Compute simple derivative vectors at a fraction of the object scale */
  fwhm = profit->guessradius * 2.0 / 4.0;
  if (fwhm < 2.0)
    fwhm = 2.0;
  sep = 2.0;

  invtwosigma2 = -(2.35*2.35/(2.0*fwhm*fwhm));
  hw = (float)(profit->objnaxisn[0]/2);
  ohw = profit->objnaxisn[0] - hw;
  hh = (float)(profit->objnaxisn[1]/2);
  ohh = profit->objnaxisn[1] - hh;
  txstart = -hw;
  ty = -hh;
  QMALLOC(dx, float, npix);
  pix = dx;
  for (j=profit->objnaxisn[1]; j--; ty+=1.0)
    {
    tx = txstart;
    y = ty < -0.5? ty + hh : ty - ohh;
    for (i=profit->objnaxisn[0]; i--; tx+=1.0)
      {
      x = tx < -0.5? tx + hw : tx - ohw;
      *(pix++) = exp(invtwosigma2*((x+sep)*(x+sep)+y*y))
		- exp(invtwosigma2*((x-sep)*(x-sep)+y*y));
      }
    }
  QMALLOC(dy, float, npix);
  pix = dy;
  ty = -hh;
  for (j=profit->objnaxisn[1]; j--; ty+=1.0)
    {
    tx = txstart;
    y = ty < -0.5? ty + hh : ty - ohh;
    for (i=profit->objnaxisn[0]; i--; tx+=1.0)
      {
      x = tx < -0.5? tx + hw : tx - ohw;
      *(pix++) = exp(invtwosigma2*(x*x+(y+sep)*(y+sep)))
		- exp(invtwosigma2*(x*x+(y-sep)*(y-sep)));
      }
    }

  QMALLOC(gdx, float, npix);
  gdxt = gdx;
  fpix = profit->objpix;
  invsig = npix/profit->sigma;
  for (i=npix; i--; fpix++)
    {
    val = *fpix > -1e29? *fpix*invsig : 0.0;
    *(gdxt++) = (val>0.0? log(1.0+val) : -log(1.0-val));
    }
  gdy = NULL;			/* to avoid gcc -Wall warnings */
  QMEMCPY(gdx, gdy, float, npix);
  fdx = fft_rtf(dx, profit->objnaxisn);
  fft_conv(gdx, fdx, profit->objnaxisn);
  fdy = fft_rtf(dy, profit->objnaxisn);
  fft_conv(gdy, fdy, profit->objnaxisn);

/* Compute estimator */
  invtwosigma2 = -1.18*1.18 / (2.0*profit->guessradius*profit->guessradius);
  xstart = -hw - obj->mx + (int)(obj->mx+0.49999);
  y = -hh -  obj->my + (int)(obj->my+0.49999);;
  spirindex = 0.0;
  gdxt = gdx;
  gdyt = gdy;
  for (j=profit->objnaxisn[1]; j--; y+=1.0)
    {
    x = xstart;
    for (i=profit->objnaxisn[0]; i--; x+=1.0)
      {
      gx = *(gdxt++);
      gy = *(gdyt++);
      if ((r2=x*x+y*y)>0.0)
        spirindex += (x*y*(gx*gx-gy*gy)+gx*gy*(y*y-x*x))/r2
			* exp(invtwosigma2*r2);
      }
    }

  free(dx);
  free(dy);
  QFFTWF_FREE(fdx);
  QFFTWF_FREE(fdy);
  free(gdx);
  free(gdy);

  return spirindex;
  }


/****** profit_moments ****************************************************
PROTO	void profit_moments(profitstruct *profit, obj2struct *obj2)
PURPOSE	Compute the 2nd order moments from the unconvolved object model.
INPUT	Profile-fitting structure,
	Pointer to obj2 structure.
OUTPUT	-.
NOTES	-.
AUTHOR	E. Bertin (IAP)
VERSION	22/04/2011
 ***/
void	 profit_moments(profitstruct *profit, obj2struct *obj2)
  {
   profstruct	*prof;
   double	dpdmx2[6], cov[4],
		*jac,*jact, *pjac,*pjact, *dcovar,*dcovart,
		*dmx2,*dmy2,*dmxy,
		m0,invm0, mx2,my2,mxy, den,invden,
		temp, temp2,invtemp2,invstemp2,
		pmx2,theta, flux, dval;
   float	 *covart;
   int		findex[MODEL_NMAX],
		i,j,p, nparam;

/*  hw = (float)(profit->modnaxisn[0]/2);*/
/*  hh = (float)(profit->modnaxisn[1]/2);*/
/*  r2max = hw<hh? hw*hw : hh*hh;*/
/*  xstart = -hw;*/
/*  y = -hh;*/
/*  pix = profit->modpix;*/
/*  mx2 = my2 = mxy = mx = my = sum = 0.0;*/
/*  for (iy=profit->modnaxisn[1]; iy--; y+=1.0)*/
/*    {*/
/*    x = xstart;*/
/*    for (ix=profit->modnaxisn[0]; ix--; x+=1.0)*/
/*      if (y*y+x*x <= r2max)*/
/*        {*/
/*        val = *(pix++);*/
/*        sum += val;*/
/*        mx  += val*x;*/
/*        my  += val*y;*/
/*        mx2 += val*x*x;*/
/*        mxy += val*x*y;*/
/*        my2 += val*y*y;*/
/*        }*/
/*      else*/
/*        pix++;*/
/*    }*/

/*  if (sum <= 1.0/BIG)*/
/*    sum = 1.0;*/
/*  mx /= sum;*/
/*  my /= sum;*/
/*  obj2->prof_mx2 = mx2 = mx2/sum - mx*mx;*/
/*  obj2->prof_my2 = my2 = my2/sum - my*my;*/
/*  obj2->prof_mxy = mxy = mxy/sum - mx*my;*/

  nparam = profit->nparam;
  if (FLAG(obj2.prof_e1err) || FLAG(obj2.prof_pol1err))
    {
/*-- Set up Jacobian matrices */
    QCALLOC(jac, double, nparam*3);
    QMALLOC(pjac, double, (nparam<2? 6 : nparam*3));
    QMALLOC(dcovar, double, nparam*nparam);
    dcovart = dcovar;
    covart = profit->covar;
    for (i=nparam*nparam; i--;)
      *(dcovart++) = (double)(*(covart++));
    dmx2 = jac;
    dmy2 = jac+nparam;
    dmxy = jac+2*nparam;
    }
  else
    jac = pjac = dcovar = dmx2 = dmy2 = dmxy = NULL;

  m0 = mx2 = my2 = mxy = 0.0;
  for (p=0; p<profit->nprof; p++)
    {
    prof = profit->prof[p];
    findex[p] = prof_moments(profit, prof, pjac);
    flux = *prof->flux;
    m0 += flux;
    mx2 += prof->mx2*flux;
    my2 += prof->my2*flux;
    mxy += prof->mxy*flux;
    if (jac)
      {
      jact = jac;
      pjact = pjac;
      for (j=nparam*3; j--;)
        *(jact++) += flux * *(pjact++);
      }
    }
  invm0 = 1.0 / m0;
  obj2->prof_mx2 = (mx2 *= invm0);
  obj2->prof_my2 = (my2 *= invm0);
  obj2->prof_mxy = (mxy *= invm0);
/* Complete the flux derivative of moments */
  if (jac)
    {
    for (p=0; p<profit->nprof; p++)
      {
      prof = profit->prof[p];
      dmx2[findex[p]] = prof->mx2 - mx2;
      dmy2[findex[p]] = prof->my2 - my2;
      dmxy[findex[p]] = prof->mxy - mxy;
      }
    jact = jac;
    for (j=nparam*3; j--;)
      *(jact++) *= invm0;
    }

/* Handle fully correlated profiles (which cause a singularity...) */
  if ((temp2=mx2*my2-mxy*mxy)<0.00694)
    {
    mx2 += 0.0833333;
    my2 += 0.0833333;
    temp2 = mx2*my2-mxy*mxy;
    }

/* Use the Jacobians to compute the moment covariance matrix */
  if (jac)
    propagate_covar(dcovar, jac, obj2->prof_mx2cov, nparam, 3,
						pjac);	/* We re-use pjac */

  if (FLAG(obj2.prof_pol1))
    {
/*--- "Polarisation", i.e. module = (a^2-b^2)/(a^2+b^2) */
    if (mx2+my2 > 1.0/BIG)
      {
      obj2->prof_pol1 = (mx2 - my2) / (mx2+my2);
      obj2->prof_pol2 = 2.0*mxy / (mx2 + my2);
      if (FLAG(obj2.prof_pol1err))
        {
/*------ Compute the Jacobian of polarisation */
        invden = 1.0/(mx2+my2);
        dpdmx2[0] =  2.0*my2*invden*invden;
        dpdmx2[1] = -2.0*mx2*invden*invden;
        dpdmx2[2] =  0.0;
        dpdmx2[3] = -2.0*mxy*invden*invden;
        dpdmx2[4] = -2.0*mxy*invden*invden;
        dpdmx2[5] =  2.0*invden;

/*------ Use the Jacobian to compute the polarisation covariance matrix */
        propagate_covar(obj2->prof_mx2cov, dpdmx2, cov, 3, 2,
						pjac);	/* We re-use pjac */
        obj2->prof_pol1err = (float)sqrt(cov[0]<0.0? 0.0: cov[0]);
        obj2->prof_pol2err = (float)sqrt(cov[3]<0.0? 0.0: cov[3]);
        obj2->prof_pol12corr = (dval=cov[0]*cov[3]) > 0.0?
					(float)(cov[1]/sqrt(dval)) : 0.0;
        }
      }
    else
      obj2->prof_pol1 = obj2->prof_pol2
	= obj2->prof_pol1err = obj2->prof_pol2err = obj2->prof_pol12corr = 0.0;
    }

  if (FLAG(obj2.prof_e1))
    {
/*--- "Ellipticity", i.e. module = (a-b)/(a+b) */
    if (mx2+my2 > 1.0/BIG)
      {
      den = (temp2>=0.0) ? mx2+my2+2.0*sqrt(temp2) : mx2+my2;
      invden = 1.0/den;
      obj2->prof_e1 = (float)(invden * (mx2 - my2));
      obj2->prof_e2 = (float)(2.0 * invden * mxy);
      if (FLAG(obj2.prof_e1err))
        {
/*------ Compute the Jacobian of ellipticity */
        invstemp2 = (temp2>=0.0) ? 1.0/sqrt(temp2) : 0.0;
        dpdmx2[0] = ( den - (1.0+my2*invstemp2)*(mx2-my2))*invden*invden;
        dpdmx2[1] = (-den - (1.0+mx2*invstemp2)*(mx2-my2))*invden*invden;
        dpdmx2[2] = 2.0*mxy*invstemp2*(mx2-my2)*invden*invden;
        dpdmx2[3] = -2.0*mxy*(1.0+my2*invstemp2)*invden*invden;
        dpdmx2[4] = -2.0*mxy*(1.0+mx2*invstemp2)*invden*invden;
        dpdmx2[5] =  (2.0*den+4.0*mxy*mxy*invstemp2)*invden*invden;

/*------ Use the Jacobian to compute the ellipticity covariance matrix */
        propagate_covar(obj2->prof_mx2cov, dpdmx2, cov, 3, 2,
					pjac);	/* We re-use pjac */
        obj2->prof_e1err = (float)sqrt(cov[0]<0.0? 0.0: cov[0]);
        obj2->prof_e2err = (float)sqrt(cov[3]<0.0? 0.0: cov[3]);
        obj2->prof_e12corr = (dval=cov[0]*cov[3]) > 0.0?
					(float)(cov[1]/sqrt(dval)) : 0.0;
        }
      }
    else
      obj2->prof_e1 = obj2->prof_e2
	= obj2->prof_e1err = obj2->prof_e2err = obj2->prof_e12corr = 0.0;
    }

  if (FLAG(obj2.prof_cxx))
    {
    invtemp2 = (temp2>=0.0) ? 1.0/temp2 : 0.0;
    obj2->prof_cxx = (float)(my2*invtemp2);
    obj2->prof_cyy = (float)(mx2*invtemp2);
    obj2->prof_cxy = (float)(-2*mxy*invtemp2);
    }

  if (FLAG(obj2.prof_a))
    {
    if ((fabs(temp=mx2-my2)) > 0.0)
      theta = atan2(2.0 * mxy,temp) / 2.0;
    else
      theta = PI/4.0;

    temp = sqrt(0.25*temp*temp+mxy*mxy);
    pmx2 = 0.5*(mx2+my2);
    obj2->prof_a = (float)sqrt(pmx2 + temp);
    obj2->prof_b = (float)sqrt(pmx2 - temp);
    obj2->prof_theta = theta*180.0/PI;
    }

/* Free memory used by Jacobians */
  free(jac);
  free(pjac);
  free(dcovar);

  return;
  }


/****** profit_convmoments ****************************************************
PROTO	void profit_convmoments(profitstruct *profit, obj2struct *obj2)
PURPOSE	Compute the 2nd order moments of the convolved object model.
INPUT	Profile-fitting structure,
	Pointer to obj2 structure.
OUTPUT	-.
NOTES	-.
AUTHOR	E. Bertin (IAP)
VERSION	12/04/2011
 ***/
void	 profit_convmoments(profitstruct *profit, obj2struct *obj2)
  {
   double	hw,hh, r2max, x,xstart,y, mx2,my2,mxy,mx,my,sum, dval,
		temp,temp2,invtemp2, pmx2, theta;
   PIXTYPE	*pix;
   int		ix,iy, w,h;

  w = profit->modnaxisn[0];
  h = profit->modnaxisn[1];
  hw = (double)(w/2);
  hh = (double)(h/2);

  r2max = hw<hh? hw*hw : hh*hh;
  xstart = -hw;
  y = -hh;
  pix = profit->cmodpix;
  mx2 = my2 = mxy = mx = my = sum = 0.0;
  for (iy=h; iy--; y+=1.0)
    {
    x = xstart;
    for (ix=w; ix--; x+=1.0)
      if (y*y+x*x <= r2max)
        {
        dval = *(pix++);
        sum += dval;
        mx  += dval*x;
        my  += dval*y;
        mx2 += dval*x*x;
        mxy += dval*x*y;
        my2 += dval*y*y;
        }
      else
        pix++;
    }

  if (sum <= 1.0/BIG)
    sum = 1.0;
  mx /= sum;
  my /= sum;
  obj2->prof_convmx2 = (mx2 = mx2/sum - mx*mx)*profit->pixstep*profit->pixstep;
  obj2->prof_convmy2 = (my2 = my2/sum - my*my)*profit->pixstep*profit->pixstep;
  obj2->prof_convmxy = (mxy = mxy/sum - mx*my)*profit->pixstep*profit->pixstep;

/* Handle fully correlated profiles (which cause a singularity...) */
  if ((temp2=mx2*my2-mxy*mxy)<0.00694)
    {
    mx2 += 0.0833333;
    my2 += 0.0833333;
    temp2 = mx2*my2-mxy*mxy;
    }

  temp2 *= profit->pixstep*profit->pixstep;

  if (FLAG(obj2.prof_convcxx))
    {
    invtemp2 = (temp2>=0.0) ? 1.0/temp2 : 0.0;
    obj2->prof_convcxx = (float)(my2*invtemp2);
    obj2->prof_convcyy = (float)(mx2*invtemp2);
    obj2->prof_convcxy = (float)(-2*mxy*invtemp2);
    }

  if (1 /*FLAG(obj2.prof_conva)*/)
    {
    if ((fabs(temp=mx2-my2)) > 0.0)
      theta = atan2(2.0 * mxy,temp) / 2.0;
    else
      theta = PI/4.0;

    temp = sqrt(0.25*temp*temp+mxy*mxy);
    pmx2 = 0.5*(mx2+my2);
    obj2->prof_conva = (float)sqrt(pmx2 + temp)*profit->pixstep;
    obj2->prof_convb = (float)sqrt(pmx2 - temp)*profit->pixstep;
    obj2->prof_convtheta = theta/DEG;
    }

  return;
  }


/****** profit_surface ****************************************************
PROTO	void profit_surface(profitstruct *profit, obj2struct *obj2)
PURPOSE	Compute surface brightnesses from the unconvolved object model.
INPUT	Pointer to the profile-fitting structure,
	Pointer to obj2 structure.
OUTPUT	-.
NOTES	-.
AUTHOR	E. Bertin (IAP)
VERSION	06/09/2011
 ***/
void	 profit_surface(profitstruct *profit, obj2struct *obj2)
  {
   profitstruct	hdprofit;
   double	dsum,dhsum,dsumoff, dhval, frac, seff;
   float	*spix, *spixt,
		val,vmax,
		scalefac, imsizefac, flux, lost, sum, lostfluxfrac;
   int		i,p, imax, npix, neff;

/* Allocate "high-definition" raster only to make measurements */
  hdprofit.modnaxisn[0] = hdprofit.modnaxisn[1] = PROFIT_HIDEFRES;
  npix = hdprofit.nmodpix = hdprofit.modnaxisn[0]*hdprofit.modnaxisn[1];
/* Find best image size factor from fitting results */
  imsizefac = 2.0*profit_minradius(profit, PROFIT_REFFFAC)/profit->pixstep
	/ (float)profit->modnaxisn[0];
  if (imsizefac<0.01)
    imsizefac = 0.01;
  else if (imsizefac>100.0)
    imsizefac = 100.0;
  scalefac = (float)hdprofit.modnaxisn[0] / (float)profit->modnaxisn[0]
	/ imsizefac;
  hdprofit.pixstep = profit->pixstep / scalefac;
  hdprofit.fluxfac = 1.0/(hdprofit.pixstep*hdprofit.pixstep);
  QCALLOC(hdprofit.modpix, float,npix*sizeof(float));

  for (p=0; p<profit->nparam; p++)
    profit->param[p] = profit->paraminit[p];
  lost = sum = 0.0;

  for (p=0; p<profit->nprof; p++)
    {
    sum += (flux = prof_add(&hdprofit, profit->prof[p],0));
    lost += flux*profit->prof[p]->lostfluxfrac;
    }
  lostfluxfrac = sum > 0.0? lost / sum : 0.0;
/*
char filename[256];
checkstruct *check;
sprintf(filename, "raster_%02d.fits", the_gal);
check=initcheck(filename, CHECK_OTHER, 0);
check->width = hdprofit.modnaxisn[0];
check->height = hdprofit.modnaxisn[1];
reinitcheck(the_field, check);
memcpy(check->pix,hdprofit.modpix,check->npix*sizeof(float));
reendcheck(the_field, check);
endcheck(check);
*/
  if (FLAG(obj2.fluxeff_prof))
    {
/*-- Sort model pixel values */
    spix = NULL;			/* to avoid gcc -Wall warnings */
    QMEMCPY(hdprofit.modpix, spix, float, npix);
    fqmedian(spix, npix);
/*-- Build a cumulative distribution */
    dsum = 0.0;
    spixt = spix;
    for (i=npix; i--;)
      dsum += (double)*(spixt++);
/*-- Find matching surface brightness */
    if (lostfluxfrac > 1.0)
      lostfluxfrac = 0.0;
    dhsum = 0.5 * dsum / (1.0-lostfluxfrac);
    dsum = lostfluxfrac * dsum / (1.0-lostfluxfrac);
    neff = 0;
    spixt = spix;
    for (i=npix; i--;)
      if ((dsum += (double)*(spixt++)) >= dhsum)
        {
        neff = i;
        break;
        }
    dhval = (double)*(spixt-1);
    seff = neff;
    dsumoff = 0.0;
    if (spixt>=spix+2)
      if (dhval > 0.0 && (frac = (dsum - dhsum) / dhval) < 1.0)
        {
        seff += frac;
        dsumoff = frac*dhval;
        dhval = dsumoff + (1.0 - frac)*(double)*(spixt-2);
        }
    obj2->fluxeff_prof = dhval;
    if (FLAG(obj2.fluxmean_prof))
      {
      dsum = dsumoff;
      for (i=neff; i--;)
        dsum += (double)*(spixt++);
      obj2->fluxmean_prof = seff > 0.0? dsum / seff : 0.0;
      }
    free(spix);
    }

/* Compute model peak */
  if (FLAG(obj2.peak_prof))
    {
/*-- Find position of maximum pixel in current hi-def raster */
    imax = 0;
    vmax = -BIG;
    spixt = hdprofit.modpix;
    for (i=npix; i--;)
      if ((val=*(spixt++))>vmax)
        {
        vmax = val;
        imax = i;
        }
    imax = npix-1 - imax;
    obj2->peak_prof = hdprofit.modpix[imax];
    }

/* Free hi-def model raster */
  free(hdprofit.modpix);

  return;