R/profitCubaMoffat.R

In ProFit: Fit Projected 2D Profiles to Galaxy Images

.profitMoffatScale=function(mag=15, fwhm=3, con=2, axrat=1, box=0){
  if(box!=0){Rbox=pi*(box+2)/(4*beta(1/(box+2),1+1/(box+2)))}else{Rbox=1}
  rd = fwhm/(2*sqrt(2^(1/con)-1))
  lumtot = (pi*rd^2)*axrat/(con-1)/Rbox
  magtot = -2.5 * log10(lumtot)
  return(1/(10^(0.4 * (mag - magtot))))
}


.profitMoffat=function(r=1, fwhm=3, con=2){
  rd = fwhm/(2*sqrt(2^(1/con)-1))
  inten = (1+(r/rd)^2)^-con
  return(inten)
}

.profitMoffatXY=function(args=c(0,0), xcen=0, ycen=0, fwhm=3, con=2, ang=0, axrat=1, box=0){
  rad=sqrt((args[1]-xcen)^2+(args[2]-ycen)^2);
  angrad=-ang*pi/180
  angmod=atan2((args[1]-xcen),(args[2]-ycen))-angrad;
  xmod=rad*sin(angmod);
  ymod=rad*cos(angmod);
  xmod=xmod/axrat;
  radmod=(abs(xmod)^(2+box)+abs(ymod)^(2+box))^(1/(2+box))
  output=.profitMoffat(radmod, fwhm=fwhm, con=con)
  return(output)
}

.profitMoffatExactSumPix=function(xpix=c(0,1), ypix=c(0,1), xcen=0, ycen=0, fwhm=3, con=2, ang=0, axrat=1, box=0, rel.tol=1e-3, abs.tol= 1e-10){
return(hcubature(.profitMoffatXY, lowerLimit=c(xpix[1],ypix[1]), upperLimit=c(xpix[2],ypix[2]), xcen=xcen, ycen=ycen, fwhm=fwhm, con=con, ang=ang, axrat=axrat, box=box, tol=rel.tol, absError=abs.tol)$integral)
}

profitRadialMoffat=function(r=1, mag=15, fwhm=3, con=2, ang=0, axrat=1, box=0){
  return= .profitMoffat(r, fwhm=fwhm, con=con)*
          .profitMoffatScale(mag=mag, fwhm=fwhm, con=con, axrat=axrat, box=box)
}

profitCubaMoffat=function(xcen=dim[1]/2, ycen=dim[2]/2, mag=15, fwhm=3, con=2, ang=0, axrat=1, box=0, dim=c(25,25), rel.tol=1e-3, abs.tol= 1e-10, plot=FALSE, ...){
  if(length(dim)==1){dim=rep(dim,2)}
  xpix=0:(dim[1]-1)
  ypix=0:(dim[2]-1)
  pixgrid=expand.grid(xpix,ypix)
  pixval={}
  for(i in 1:length(pixgrid[,1])){
    pixval=c(pixval, .profitMoffatExactSumPix(c(pixgrid[i,1],pixgrid[i,1]+1), c(pixgrid[i,2],pixgrid[i,2]+1), xcen=xcen, ycen=ycen, fwhm=fwhm, con=con, ang=ang, axrat=axrat, box=box, rel.tol= rel.tol, abs.tol= abs.tol))
  }
  output=matrix(pixval*.profitMoffatScale(mag=mag, fwhm=fwhm, con=con, axrat=axrat, box=box),dim[1],dim[2])
  
  if(plot){
	  magimage(output, ...)
  }
  
  return=output
}