How do I convert spirographic values for r, R, and a to the code for a polar plot?

I'm trying to create a polar plot using the radius of a large circle, a small circle, and the distance from the center of the small circle to the drawing point. I don't know how these values relate to what is used in a MATLAB code.

Answer 1

[Star Strider]

If you want to plot a hypotrochoid, you do not need a polar plot. This code uses a Cartesian plot:

A = 5.0;
B = 0.5;
d = 2.0;
t = linspace(0, 2*pi, 500);
x=(A-B)*cos(t)+d*cos((A-B)/(B)*t);
y=(A-B)*sin(t)-d*sin((A-B)/(B)*t);

figure(1)
plot(x, y, '-r')
grid
axis equal

to produce this figure: