SYNOPSIS

ch [p|z|0]

DESCRIPTION

The ch command causes subsequent graphics-filter z commands (whether entered from the keyboard or a command file) to be treated as HP-GL plotter p commands, or vice versa.

You may, for example, want to display the plot on a video terminal while developing a command file. When the command file is fine-tuned, use ch to automatically substitute pen-plotter p commands for the graphics-filter z commands in the file as it is executing.

The ch command can be useful for debugging a z-based command file, by changing the target of the drawing command to the pen plotter with no pen plotter initialized. In this case, nothing will be drawn, but you will be able to observe error messages on the screen that might otherwise be obscured by graphics. Also, quiet mode (invoked by the zq command) doesn't turn off the printing of messages when the pen plotter is the drawing target.

With no arguments to ch,C-PLOT indicates whether or not the commands are being changed. A z argument causes HP-GL p commands to be changed to graphics filter z commands. A p argument does the reverse. An argument of 0 makes the p and z commands work normally.

EXAMPLE

ch p