;Create a random 'catalog' with 1 in non masked pixels (whose
;subscripts list is the in input)
function create_random, image, in


nxpix = n_elements(image[*,0])
nypix = n_elements(image[0,*])
res   = dblarr(nxpix, nypix)
res[in] = 1
 

return, res
end