ly, the size of a node is determined by smallest width and height
needed to contain its label and image, if any, with a margin specified by
the <A HREF=attrs.html#d:margin><TT>margin</TT></A> attribute. The width
and height must also be at least as large as the sizes specified by the
<A HREF=attrs.html#d:width><TT>width</TT></A> and
<A HREF=attrs.html#d:height><TT>height</TT></A> attributes, which specify
the minimum values for these parameters. 
See the <A HREF=attrs.html#d:fixedsize><TT>fixedsize</TT></A>