OVERLAY= and Related Options
Values specified with the COVERLAY=, OVERLAYSYM=,
and OVERLAYSYMHT=
options are matched with variables in the corresponding positions in
the OVERLAY= variable list.
Values specified with the COVERLAY2=, OVERLAY2SYM=,
and OVERLAY2SYMHT=
options are matched with variables in the corresponding positions in
the OVERLAY2= variable list.
When one of these options is not specified, the
associated values are taken from the SYMBOL definitions currently in
effect. If an option is specified but lists fewer values than the
number of overlay variables, the overlays for the remaining unmatched
variables use values from the SYMBOL definitions.
SYMBOL1 is used to plot the process variable, so the
SYMBOL definitions
associated by default with the overlay plots start with SYMBOL2.
The vertical axis of a control chart is scaled to accommodate data for
the process variable and all the points on any overlays.
If the range of overlay variable values is much greater than the range
of process variable values, the control chart may be compressed
and difficult to read.
Copyright © 2001 by SAS Institute Inc., Cary, NC, USA. All rights reserved.
