Create an ellipse using STREL command

See more:

MatLab

How can I create an ellipse in matlab using STREL command?
When I execute the bellow code I just have a white plane.

a=zeros(300,400);
a(150,200)=1;
b=strel('ball',5,5,0);
c=imdilate(a,b);
imshow(c)

when I use the command imshow(c,[]), or imagesc(c) then I have a ball shape as the output. kindly tell me how can I creat an ellipse.