PLOT Subcommand (CATPCA command)
The PLOT
subcommand
controls the display of plots. The default keywords are OBJECT
and LOADING
. That is, the two keywords are in effect when the PLOT
subcommand is omitted or when the PLOT
subcommand is given without any keyword.
If a keyword is duplicated (for example, /PLOT = RESID RESID
), only the last keyword is effective.
If the keyword NONE
is used with
other keywords (for example, /PLOT = RESID
NONE LOADING
), only the keywords following NONE
are effective. When keywords contradict,
the later keyword overwrites the earlier keywords.
- All the variables to be plotted must be specified
on the
ANALYSIS
subcommand. - If the variable list following the keywords
CATEGORIES
,TRANS
,RESID
, andPROJCENTR
is empty, it will cause a syntax error, and the procedure will terminate. - The variables in the variable list for labeling the
object point following
OBJECT
,BIPLOT
, andTRIPLOT
must be specified on theVARIABLES
subcommand but need not appear on theANALYSIS
subcommand. This flexibility means that variables that are not included in the analysis can still be used to label plots. - The keyword
TO
in a variable list can only be used with variables that are in theANALYSIS
subcommand, andTO
applies only to the order of the variables in theANALYSIS
subcommand. For variables that are in theVARIABLES
subcommand but not in theANALYSIS
subcommand, the keywordTO
cannot be used. For example, if/VARIABLES = v1 TO v5
and/ANALYSIS = v2 v1 v4
, then/PLOT OBJECT(v1 TO v4)
will give two object plots, one plot labeled with v1 and one plot labeled with v4. - For multidimensional plots, all of the dimensions
in the solution are produced in a matrix scatterplot if the number
of dimensions in the solution is greater than 2 and the
NDIM
plot keyword is not specified; if the number of dimensions in the solution is 2, a scatterplot is produced.
The following keywords can be specified:
OBJECT(varlist)(n). Plots of the
object points. Following the keyword, a list of variables
in parentheses can be given to indicate that plots of object points
labeled with the categories of the variables should be produced (one
plot for each variable). The variables to label the objects must be
specified on the VARIABLES
subcommand
but need not appear on the ANALYSIS
subcommand. If the variable list is omitted, a plot that is labeled
with case numbers is produced.
CATEGORY(varlist)(n). Plots of the
category points. Both the centroid coordinates and the
vector coordinates are plotted. A list of variables must be given
in parentheses following the keyword. For variables with optimal scaling
level MNOM
, categories are in
the centroids of the objects in the particular categories. For all
other optimal scaling levels, categories are on a vector through the
origin.
LOADING(varlist (CENTR(varlist)))(l). Plot of the
component loadings optionally with centroids. By default,
all variables with an optimal scaling level that results in vector
quantification (that is, SPORD
, SPNOM
, ORDI
, NOMI
, and
NUME
) are included in this plot. LOADING
can be followed by a varlist to
select the loadings to include in the plot. When "LOADING("
or the varlist following "LOADING("
is followed by the keyword CENTR
in parentheses, centroids are included
in the plot for all variables with optimal scaling level MNOM
. CENTR
can be followed by a varlist in parentheses to select MNOM
variables whose centroids are to be
included in the plot. When all variables have the MNOM
scaling level, this plot cannot be
produced.
TRANS(varlist(n))(n). Transformation
plots per variable (optimal category quantifications against category
indicators). Following the keyword, a list of variables
in parentheses must be given. MNOM
variables in the varlist can be followed by a number of dimensions
in parentheses to indicate that you want to display p transformation plots, one plot for each
of the first p dimensions. If
the number of dimensions is not specified, a plot for the first dimension
is produced.
RESID(varlist(n))(n). Plot of residuals
per variable (approximation against optimal category quantifications). Following the keyword, a list of variables in parentheses must be
given. MNOM
variables in the
varlist can be followed by a number of dimensions in parentheses to
indicate that you want to display p residual plots, one plot for each of the first p dimensions. If the number of dimensions is not specified,
a plot for the first dimension is produced.
BIPLOT(keyword(varlist)) (varlist)(n). Plot of objects
and variables. The coordinates for the variables can be
chosen to be component loading or centroids, using the LOADING
or CENTR
keyword in parentheses following BIPLOT
. When no keyword is given, component loadings are plotted. When
NORMALIZATION
= INDEPENDENT
, this plot is incorrect and
therefore not available. Following LOADING
or CENTR
, a list of variables
in parentheses can be given to indicate the variables to be included
in the plot. If the variable list is omitted, a plot including all
variables is produced. Following BIPLOT
, a list of variables in parentheses can be given to indicate that
plots with objects that are labeled with the categories of the variables
should be produced (one plot for each variable). The variables to
label the objects must be specified on the VARIABLES
subcommand but need not appear on the ANALYSIS
subcommand. If the variable list
is omitted, a plot with objects labeled with case numbers is produced.
TRIPLOT(varlist(varlist))(n). A plot of object
points, component loadings for variables with an optimal scaling level
that results in vector quantification (that is, SPORD
, SPNOM
, ORDI
, NOMI
, and NUME
), and centroids
for variables with optimal scaling level MNOM
. Following the keyword, a list of variables
in parentheses can be given to indicate the variables to include in
the plot. If the variable list is omitted, all variables are included.
The varlist can contain a second varlist in parentheses to indicate
that triplots with objects labeled with the categories of the variables
in this variable list should be produced (one plot for each variable).
The variables to label the objects must be specified on the VARIABLES
subcommand but need not appear
on the ANALYSIS
subcommand. If
this second variable list is omitted, a plot with objects labeled
with case numbers is produced. When NORMALIZATION
= INDEPENDENT
, this plot is incorrect and therefore not
available.
JOINTCAT(varlist)(n). Joint plot of the category points for the variables in the varlist. If no varlist is given, the category points for all variables are displayed.
PROJCENTR(varname, varlist)(n). Plot of the
centroids of a variable projected on each of the variables in the
varlist. You cannot project centroids of a variable on
variables with MNOM
optimal scaling
level; thus, a variable that has MNOM
optimal scaling level can be specified as the variable to be projected
but not in the list of variables to be projected on. When this plot
is requested, a table with the coordinates of the projected centroids
is also displayed.
VAF. Barcharts of variable variance accounted for. There is one barchart for each dimension and one for the total variance accounted for over all dimensions..
LDELLAREA(threshold). Confidence ellipses for loading plots. If
RESAMPLE=BOOTSTRAP
and DIMENSION=2
, confidence ellipses
are plotted. You can control the display of loadings with their confidence ellipses in the
plot by specifying a threshold ellipse area in parentheses of the general form:
(GT|LT
STDEV|AREA
value). STDEV
represents the mean area plus the
number of standard deviations specified for the value. You can use the greater than (>) and
less than signs (<) instead of GT
and LT
. The default
setting is (> AREA 0)
. This displays all loadings with confidence
ellipses.
OBELLAREA(threshold). Confidence ellipses for object plots. If
RESAMPLE=BOOTSTRAP
and DIMENSION=2
, confidence ellipses
are plotted. You can control the display of objects with their confidence ellipses in the plot
by specifying a threshold ellipse area in parentheses of the general form:
(GT|LT
STDEV|AREA
value). STDEV
represents the mean area plus the
number of standard deviations specified for the value. You can use the greater than (>) and
less than signs (<) instead of GT
and LT
. The default
setting is (> STDEV 2)
. This displays all objects with confidence
ellipses.
CTELLAREA(threshold). Confidence ellipses for category plots. If
RESAMPLE=BOOTSTRAP
and DIMENSION=2
, confidence ellipses
are plotted. You can control the display of loadings with their confidence ellipses in the
plot by specifying a threshold ellipse area in parentheses of the general form:
(GT|LT
STDEV|AREA
value). STDEV
represents the mean area plus the
number of standard deviations specified for the value. You can use the greater than (>) and
less than signs (<) instead of GT
and LT
. The default
setting is (> AREA 2)
. This displays all categories with confidence
ellipses.
NELLPNT(integer). Number of ellipse contour points. If
RESAMPLE=BOOTSTRAP
and DIMENSION=2
, confidence ellipses are
plotted as a path between a number of points on the ellipse contours. The number of these points
influences how smooth the ellipses look. The default number of ellipse contour points is 40.
NONE. No plots.
- For all keywords that allow a variable list, the user can specify an optional parameter l
in parentheses after the variable list in order to control the global upper boundary of variable
name/label and value label lengths in the plot. Note that this boundary is applied uniformly to
all variables in the list. The label length parameter l can take any non-negative integer
that is less than or equal to the applicable maximum length (64 for variable names, 255 for
variable labels, and 60 for value labels). If l = 0, names/values instead of
variable/value labels are displayed to indicate variables/categories. If l is not
specified,
CATPCA
assumes that each variable name/label and value label is displayed at its full length. If l is an integer that is larger than the applicable maximum, we reset it to the applicable maximum but do not issue a warning. If a positive value of l is given but some or all variables/category values do not have labels, then, for those variables/values, the names/values themselves are used as the labels.
In addition to the plot keywords, the following keyword can be specified:
NDIM(value,value). Dimension
pairs to be plotted. NDIM
is followed by a pair of values in parentheses. If NDIM
is not specified or is specified without
parameter values, a matrix scatterplot including all dimensions is
produced.
- The first value (an integer that can range from 1 to the number of dimensions in the solution minus 1) indicates the dimension that is plotted against higher dimensions.
- The second value (an integer that can range from 2 to the number of dimensions in the solution) indicates the highest dimension to be used in plotting the dimension pairs.
- The
NDIM
specification applies to all requested multidimensional plots.