function bin_image_xy,x,y,im,zero=zero, bin=bin,crop=crop

        if n_params(0) eq 0 then begin
          print,'im = bin_image_xy(x, y [, im], zero=zero, bin=bin, crop=crop, fits=fits)
          print,'Bin x,y vectors into an image
          print,'If im is supplied, bin image into im rather than creating new array
          print,'If /crop, crop image (in this case the x,y zero points are returned in zero
          print,'If bin is supplied, image is binned by bin, with x,y assumed in fits
          print,'  convension (i.e., bottem-left of first pixel is 0.5, 0.5)'
          print,'Note that this routine is not appropriate if x,y are not integers'
          retall
        endif
	if not keyword_set(bin) then bin=1.0
	xr = minmax(x)
	yr = minmax(y)
	if not keyword_set(crop) then begin
	  xr(0) = 1 & yr(0) = 1
	endif
        xs = round((xr(1)-xr(0))/bin)+1
	ys = round((yr(1)-yr(0))/bin)+1
;        xr = xr - 1
;        yr = yr - 1
	if n_elements(im) eq 0 then im = intarr(xs, ys)
	newx = round((x-xr(0) + 0.5)/bin + 0.5) - 1
	newy = round((y-yr(0) + 0.5)/bin + 0.5) - 1
	for i=0l,n_elements(x)-1 do im(newx(i), newy(i)) = $
          im(newx(i), newy(i)) + 1
	zero = [xr(0), yr(0)]
	return,im
	end