How to convert x,y coordinates to an angle?

Question

Microsoft provide an excellent SVG gradient maker so IE9 can also have \"CSS3\" gradients (click Custom).

I currently utilise their logic for my Fireworks and Dreamw

Answer 1

If you get deltaX and deltaY from your coordinates then Math.atan2 returns the arctangent of the quotient of its arguments. The return value is in radians.

var deltaX = x2 - x1;
var deltaY = y2 - y1;
var rad = Math.atan2(deltaY, deltaX); // In radians

Then you can convert it to degrees as easy as:

var deg = rad * (180 / Math.PI)

Edit

There was some bugs in my initial answer. I believe in the updated answer all bugs are addressed. Please comment here if you think there is a problem here.