set( radius, phi, theta ) {

		this.radius = radius;
		this.phi = phi;
		this.theta = theta;

		return this;

	}
Sets the spherical components by copying the given values.

@param {number} radius - The radius.
@param {number} phi - The polar angle.
@param {number} theta - The azimuthal angle.
@return {Spherical} A reference to this spherical.