#1,146 – Polar Coordinate System

In most cases when you’re working with graphical objects, you use a cartesian coordinate system, where each point is represented as an X and a Y value, indicating the point’s distance from an origin in two different dimensions.

You can also express points in a two-dimensional system using a polar coordinate system.  Each point in a polar coordinate system is represented with two values:

  • A radius value, describing how far the point is from an origin  (range is any non-negative number)
  • An angular coordinate, describing how many degrees around the circle the point is located, typically from a horizontal ray extending to the right of the origin  (range typically [0, 360) degrees or [0, 2*pi) radians)

Below is a picture showing two sample points expressed in polar coordinates.

  • (2.0, 60) – Radius = 2, Angle = 60 degrees (counterclockwise) from horizontal
  • (1.0, 180) – Radius = 1, Angle = 180 degrees (counterclockwise) from horizontal

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