spherical coordinates

• 1. 

  N-PLURAL three coordinates that define the location of a point in three-dimensional space in terms of the length r of its radius vector, the angle, θ, which this vector makes with one axis, and the angle, φ, made by a second axis, perpendicular to the first, with the plane containing the first axis and the point. Usually written (r, θ, φ) 球面坐标