relationship between "size=" and output image resolution

What is the relationship between "size=30,40" and the resulting png image resolutions of x=2880, y=3837 ?
The x and y factors are close but not identical. Why?

Thanks

The size attribute specifies

The size attribute specifies the desired maximum size, in inches, of the graph drawing. The drawing is scaled down uniformly to fit the specified size. The actual bitmap output uses the dpi attribute to determine how many pixels per inch to use when converting the drawing to a bitmap. In this case, it appears to be the default of 96. As for the y value seeming a bit large, this could be for various reasons such as margins or an oddity in the renderer. I would have to know the Graphviz version and configuration and the graph to supply a definitive answer.

Recent comments