Creating image with large width

Hello,
I have a diagram with width 3236px, how can i create a single image of complete go js diagram?
i used scale:1 but it seems to chop of the image after 2000px.

You must set the maxSize to a larger value, it is go.Size(2000,2000) by default.

See: http://gojs.net/latest/api/symbols/Diagram.html#makeImageData