structural:reformatting
Spherical vectors

A spherical vector is another method for extending the concept of polar vectors into three dimensions. It is akin to an arrow in the spherical coordinate system. A spherical vector is specified by a magnitude, an azimuth angle, and a zenith angle. The magnitude is usually represented as ρ. The azimuth angle, usually represented as θ, is the (counter clockwise) offset from the positive x -axis. The zenith angle, usually represented as φ, is the offset from the positive z -axis. Both angles are typically reduced to lie within the range from zero (inclusive) to 2 π (exclusive).