From my small experience with tikz in Latex, it seems that the boundary of a tikz image is set automatically based on its contents. This caused me some trouble when I was trying to scale and align multiple tikz images.
Is there a way to set the boundary manually? For instance perhaps I want an image with nodes at (1,1) and (2,1) and a boundary which is rectangular with corners at (0,0) and (3,2). How would this be achieved?
\clip (-0,05) rectangle (3,2);
welcome to tex.se!\path[use as bounding box] (0,0) rectangle (1,1);
See p. 175 of the pgfmanual for more details.