idlastro / Math and Statistics: CLEANPLOT

[Source code]

NAME
CLEANPLOT
PURPOSE
Reset all plotting system variables (!P,!X,!Y,!Z) to their default values
EXPLANATION
Reset all system variables (!P,!X,!Y,!Z) which are set by the user
and which affect plotting to their default values.
CALLING SEQUENCE
Cleanplot, [ /Silent, /ShowOnly]
INPUTS
None
OPTIONAL KEYWORD INPUT
/SHOWONLY - If set, then CLEANPLOT will display the plotting system
          variables with nondefault values, but it will not reset them.
/SILENT - If set, then CLEANPLOT will not display a message giving the 
          the system variables tags being reset.    One cannot set 
           both /SILENT and /SHOWONLY
OUTPUTS
None
SIDE EFFECTS
The system variables that concern plotting are reset to their default
values.  A message is output for each variable changed.
The !P.CLIP and CRANGE, S, WINDOW, and REGION fields of the
!X, !Y, and !Z system variables are not checked since these are
set by the graphics device and not by the user.   
PROCEDURE
This does NOT reset the plotting device.
This does not change any system variables that don't control plotting.
RESTRICTIONS
If user default values for !P, !X, !Y and !Z are different from
the defaults adopted below, user should change P_old etc accordingly
MODIFICATION HISTORY
Written IDL Version 2.3.0  W. Landsman & K. Venkatakrishna May '92
Handle new system variables in V3.0.0     W. Landsman   Dec 92
Assume user has at least V3.0.0           W. Landsman   August 95
V5.0 has 60 instead of 30 TICKV values    W. Landsman   Sep. 97
Change !D.N_COLORS to !D.TABLE_SIZE for 24 bit displays
        W. Landsman  April 1998
Added silent keyword to supress output & modified X_old to
handle the new !X and !Y tags in IDL 5.4   S. Penton     July 2000
Test for visual depth if > V5.1   W. Landsman     July 2000
Macs can report a visual depth of 32  W. Landsman  March 2001
Call device,get_visual_depth only for device which allow it 
         W. Landsman  June 2001
Default !P.color is 16777215 for 16 bit systems 
                W. Landsman/M. Hadfield   November 2001 
Added ShowOnly keyword   W. Landsman      April 2002
Use V6.0 notation W. Landsman April 2011