Make artificial 2d signal
sig = MakeImage(Name,n[,par])
string, one of
(par = length of side [n/2])
(par = radius [n/4])
(par = number [10])
(par = major/minor axes ratio [2])
(par = major/minor axes ratio [2])
(par = major/minor axes ratio [2])
desired signal dimension
optional parameter, defaults in []'s above
n by n images