Keyboard Instead of Mouse Control

[fedora]

Currently, I have this script in my application to move the player in a circle using the mouse (taken from this example: http://phaser.io/sandbox/CpErwgAd/play) :

    var mouseX = this.input.x;    var mouseY = this.input.y;        theta = Math.atan2(mouseX-cX, mouseY-cY)        var newX = Math.sin(theta) * radius;    var newY = Math.cos(theta) * radius;        rocket.x=cX + newX;    rocket.y=cY + newY;

I would like to change the above to key control ("A"/'D") -- but can't get the right code to work.  

 

FYI, I am using the cursor arrows for other movement with no problem.

 

Any assistance would be greatly appreciated.

[fedora]

In case anyone is looking for the answer -- the below is thanks to the expertise of jmp909 (http://www.html5gamedevs.com/topic/18140-how-drag-sprite-around-circle/#entry107548)

 

here's one way to do it using Sin/Cos

http://phaser.io/sandbox/gXbgAMnK/play

 

and another using phaser's point rotation function (with a distance constraint... http://phaser.io/doc...nt.html#rotate)

http://phaser.io/sandbox/wDpGcNHm/play

 

I've taken 0 angle as the top of the circle, but that's not the normal way angles are measured so i've shifted the value accordingly