zf
select filter
SYNOPSIS
zf
zf1
or
zf2
DESCRIPTION
The zf commands lets you maintain two active graphic filters. Entering zf switches between filter 1 and filter 2; zf1 selects filter 1 and zf2 selects filter 2. If no filter is active when a zf command is entered, C-PLOT will prompt for a filter to be specified. Filter 1 is the default.
Once a filter is selected, it remains the target of z commands until the other is selected.