three.js/src/math/Cylindrical.d.ts

import { Vector3 } from './Vector3';

export class Cylindrical {
  constructor(radius?: number, theta?: number, y?: number);

  radius: number;
  theta: number;
  y: number;

  clone(): this;
  copy(other: Cylindrical): this;
  set(radius: number, theta: number, y: number): this;
  setFromVector3(vec3: Vector3): this;
}