Get mouse moving speed

I didn't get a exact solution/calculation from stackoverflow so i created a question

var timestamp = null;
var mY = 0;
$(document).mousemove(function(e) {
    var now = Date.now();
    currentmY = e.pageY;



    mY = e.pageY;
    timestamp = now;
});

I need to get a speed value when mouse move vertical angle.

https://jsfiddle.net/58tjr9o1/

The speed is simply the distance divided by the time it took:

speed = distance / time

The distance is currentmY - mY, while the time is now - timestamp. So in the end, you get:

var timestamp = 0;
var mY = 0;
$(document).mousemove(function(e) {
    var now = Date.now();
    var currentmY = e.screenY;

    var dt = now - timestamp;
    var distance = Math.abs(currentmY - mY);
    var speed = Math.round(distance / dt * 1000);
    console.log(dt, distance, speed);
    document.getElementById("speed").innerHTML = speed;
    
    mY = currentmY;
    timestamp = now;
});

Note the * 1000, since the timestamp is in milliseconds. The speed is here in pixels/second.

See this updated fiddle.