How can i color into circle element when i plot the curve?

Answer 1

[Image Analyst]

One way is to use the scatter() function and tell it to use 'filled' markers.

Another way is to use plot and use a gigantic marker size

plot(x, y, 'r.-', 'MarkerSize', 100);

A third way is to use the rectangle() function - see the help for an example.

Answer 2

[KSSV]

th = linspace(0,2*pi) ; 
x = cos(th) ; 
y = sin(th) ; 

patch(x,y,'r')