How do you create a contour plot for a graph using java script

[D Manoy]

I m trying to create a contour plot for a scan data. I cant seem to fing any tutorials that would help in crating such figure. Please help

[Frank Carver]

And you want to do this relatively complex math in JavaScript ? I'd really think a lot before making a design decision like that; JavaScript is much better suited to simple string processing and stuff.
As for contour plot algorithms, it's a long time since I last had to do this. I'd start by searching the net to see if there are any existing packages to do what you want. Getting it right is surprisingly tricky.