When exporting graphs to bitmap, PostScript, or
SVG formats, a combination of the four command line options
-xmin X1-ymin Y1-xmax X2-ymax Y2 enables an image part to be exported
instead of the entire image. The image part to be exported is specified by
a bounding rectangle with the upper left corner at (X1,Y1)
and the lower right corner at (X2,Y2), the graph origin always
being at (0,0).