3D / three.js vertical movement formula?

Question

three.js

Hello everyone, I had such a problem, I need a formula for the movement of the vertical movement of the camera.
Horizontally I was found on the internet vertically no, I hope you can help.
Horizontal:
right...
where x and z is the camera position
camera.position.x = x * Math.cos(rotSpeed) - z * Math.sin(rotSpeed);
camera.position.z = z * Math.cos(rotSpeed) + x * Math.sin(rotSpeed);