How to plot contours using radial cordinates?

I don't know if there is a plotting method in the java api for polar coordinates. I want to think I saw one but here is the formula for converting between.

// polar to Cartesian
double x = Math.cos( angleInRadians ) * radius;
double y = Math.sin( angleInRadians ) * radius;

// Cartesian to polar.
double radius = Math.sqrt( x * x + y * y );
double angleInRadians = Math.acos( x / radius );