Visualizing Categorical Data: catplot
$Version: 1.4 (9 Nov 2000)
Michael Friendly
York University
 
 Plots for logit models fit by PROC CATMOD
 The catplot macro is designed to plot observed and/or predicted
 values for logit models fit by the CATMOD procedure.  The macro uses
 the output data set produced with the OUT= option on the RESPONSE
 statement.  This data set normally contains both logit values
 (_type_='FUNCTION') and probability values (_type_='PROB').  Either
 set may be plotted, as specified by the TYPE= parameter.
 The horizontal variable may be character (XC=) or numeric (X=).
 A separate curve is drawn for each value of the CLASS= variable,
 connecting predicted values, with optional standard error bars,
 and separate plots are drawn for each value of the BYVAR= variable.
 
Usage
 The catplot macro is called with keyword parameters.  The arguments 
 may be listed within parentheses in any order, separated by commas.
 For example: 
 proc catmod;
        direct husinc;
        response / out=logits;
        model labour = husinc children; 
 %catplot(data=logits, x=husinc, y=_pred_, class=labor, byvar=children);
 
Parameters
  - DATA= 
- The name of the SAS dataset to be plotted, which must be
		an output data set from PROC CATMOD.  If DATA= is not
		specified, the most recently created data set is used.
  
- X= 
- Name of a numeric factor variable to be used as the horizontal
		variable in plots.  Use the XC= parameter to specify a
		character variable.  You must specify either the X= or XC=
		variable.
  
- XC= 
- Name of a character factor variable used as the horizontal
		variable in plots.
  
- Y= 
- Name of the ordinate variable.  Y=_PRED_ plots the predicted
		value; Y=_OBS_ plots the observed value.
  
- CLASS= 
- The name of a factor variable, used to define separate curves
		which are plotted for each level of this variable.
  
- BYVAR= 
- Name of one or more factor variables to be used to define 
		multiple panels in plots.  
  
- BYFMT= 
- Name of a SAS format used to format the value of BYVARs
		for display in one panel of the plot(s).
  
- TYPE= 
- The type of oobservations to be plotted.  TYPE=FUNCTION (the
		default) gives plots of the logit value; TYPE=PROB gives
		plots of the probability value.
  
- Z= 
- Standard error multiple for confidence intervals around
		predicted values, e.g., Z=1.96 gives 95% CI. To suppress error
		bars, use Z=0.  The default is Z=1, giving 67% CI.
  
- CLFMT= 
- Name of a SAS format used to format the value the CLASS=
		variable for display in each panel of the plot(s).
  
- CLSIDE= 
- Specifies whether the values of the CLASS= variable should
		be labelled by annotation in the plot or by a legend.  If
		CLSIDE=LEFT or CLSIDE=FIRST, CLASS= values are written at the
		left side of each curve.  If CLSIDE=RIGHT or CLSIDE=LAST,
		CLASS= values are written at the right side of each curve.
		If CLSIDE=NONE, CLASS= values appear in the legend.
  
- XFMT= 
- Name of a SAS format used to format the values of the
   horizontal variable.
                        
  
- ANNO= 
- Name of an additional input annotate data set
  
- SYMBOLS= 
- List of SAS/GRAPH symbols for the levels of the CLASS= variable.  
		There should be as many symbols as there are distinct values of 
		the CLASS=variable.
  
- COLORS= 
- List of SAS/GRAPH colors for the levels
		of the CLASS= variable.  There should be as many colors as there
		are distinct values of the CLASS= variable.
  
- LINES= 
- List of SAS/GRAPH line styles for the
		levels of the CLASS= variable.  There should be as many lines as 
		there are distinct values of the CLASS= variable.
  
- HAXIS= 
- Axis statement for custom horizontal axis, e.g., HAXIS=AXIS2
  
- VAXIS= 
- Axis statement for custom response axis, e.g., VAXIS=AXIS1.  If no axis statement is defined, the program uses
AXIS1 LABEL=(a=90).
  
- LEGEND= 
- Legend statement for custom CLASS legend, e.g., LEGEND=LEGEND1
Example
[None yet]
See also
inflogis Influence plot for logistic regression models
pscale Construct annotations for a probability scale