Figure 1. Using PGPLOT

$ ./pgdemo

Graphics device/type (? to see list, default /NULL): ?

PGPLOT v5.0.0 Copyright 1994 California Institute of Technology
Legal PGPLOT device types are:
/NULL  (Null device, no output)
/PS    (PostScript file, landscape orientation)
/VPS   (PostScript file, portrait orientation)
/CPS   (Colour PostScript file, landscape orientation)
/VCPS  (Colour PostScript file, portrait orientation)
/XWINDOW (X window window@node:display.screen/xw)
/XSERVE  (A /XWINDOW window that persists for re-use)
Graphics device/type (? to see list, default /NULL): /XWINDOW