CDFPLOT Statement: CAPABILITY Procedure

specify variables for which to create cdf plots. If you specify a VAR statement, the variables must also be listed in the VAR statement. Otherwise, the variables can be any numeric variables in the input data set. If you do not specify variables in a CDFPLOT statement, then a cdf plot is created for each variable listed in the VAR statement, or for each numeric variable in the input data set if you do not use a VAR statement.

For example, suppose a data set named steel contains exactly three numeric variables, length, width and height. The following statements create a cdf plot for each of the three variables:

proc capability data=steel;
   cdfplot;
run;

The following statements create a cdf plot for length and a cdf plot for width:

proc capability data=steel;
   var length width;
   cdfplot;
run;

The following statements create a cdf plot for width:

proc capability data=steel;
   var length width;
   cdfplot width;
run;

By default, the horizontal axis of a cdf plot is labeled with the variable name. If you specify a label for a variable, however, the label is used. The default vertical axis label is Cumulative Percent, and the axis is scaled in percent of observations.

If you specify a SPEC statement or a SPEC= data set in addition to the CDFPLOT statement, then the specification limits for each variable are displayed as reference lines and are identified in a legend.

add features to plots. All options appear after the slash (/) in the CDFPLOT statement. In the following example, the NORMAL option superimposes a normal cdf on the plot, and the CTEXT= option specifies the color of the text.

proc capability data=steel;
   cdfplot length / normal ctext=yellow;
run;