pro model_vis,map,u,v,mvis,xyint,help=help

if keyword_set(help) then begin
	print,'PURPOSE: '
	print,'	Compute model visibility arrays from MEM maps generated by MEM_NJIT'
	print,'HELP: '
	print,'	pro model_vis,map,u,v,mvis,xyint'
	print,'	inputs:	map (map/array produced by MEM_NJIT, i.e. image.map)'
	print,'		u,v (u and v arrays, outputs from mem_map.pro)'
	print,'		xyint (spatial scale, arcsec/pixel used in MEM_NJIT)'
	print,'	outputs:mvis (model visibility complex array)'
	print,'AUTHOR:'
	print,'	Rick Pernak, Goddard Space Flight Center'
	return
endif

;map=shift(map,4,0)
dim = size(map,/dimensions)
n = dim[0] ;number of pixels, assumed to be a square map, so dim[0]=dim[1]
i = complex(0,1)
u_new = u/206265.		;converted to inverse radians in mem_map
v_new = v/206265.		;converting back to inverse arcsec
half = n/2					;half of the map, for centering purposes

flux_arr = dblarr(128,128)

for ctrx = 0,(n-1) do begin ;'counter x', moving in x direction
	x = (ctrx+1)-(half+1)
	for ctry = 0,(n-1) do begin; 'counter y', moving in y direction
		y = (ctry+1)-(half+1)
		flux = map[ctrx,ctry]
		if (ctrx eq 0) and (ctry eq 0) then begin
			mvis = flux * exp(2*!pi*i*(u_new*(xyint*x)+v_new*(xyint*x)))
		endif else begin
			mvis = mvis + (flux * exp(2*!pi*i*(u_new*(xyint*x)+v_new*(xyint*y))))
		endelse
	endfor
endfor

return
end