9.3. - zf select filter
lets you maintain up to eight active graphics filters.
zf or zf#Entering
zf alone selects the next filter in the sequence from 1 to 8.
If the current filter is 8, filter 1 is selected.
zf1 selects filter 1,
zf2 selects filter 2, etc.
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 another is chosen.