PLOTS Subcommand (SURVIVAL command)

PLOTS produces plots of the cumulative survival distribution, the hazard function, and the probability density function. The PLOTS subcommand can plot only the survival functions generated by the TABLE subcommand; PLOTS cannot eliminate control variables.

  • When specified by itself, the PLOTS subcommand produces all available plots for each survival variable. Points on each plot are identified by values of the first-order control variables. If second-order controls are used, a separate plot is generated for every value of the second-order control variables.
  • To request specific plots, specify, in parentheses following PLOTS, any combination of the keywords defined below.
  • Optionally, generate plots for only a subset of the requested life tables. Use the same syntax as used on the TABLE subcommand for specifying survival and control variables, omitting the value ranges. Each survival variable named on PLOTS must have as many control levels as were specified for that variable on TABLE. However, only one control variable needs to be present for each level. If a required control level is missing on the PLOTS specification, the default BY ALL is used for that level. The keyword ALL can be used to refer to an entire set of survival or control variables.
  • To determine the number of plots that will be produced, multiply the number of functions plotted by the number of survival variables times the number of first-order controls times the number of distinct values represented in all of the second-order controls.

ALL. Plot all available functions. ALL is the default if PLOTS is used without specifications.

LOGSURV. Plot the cumulative survival distribution on a logarithmic scale.

SURVIVAL. Plot the cumulative survival distribution on a linear scale.

HAZARD. Plot the hazard function.

DENSITY. Plot the density function.

OMS. Plot the one-minus-survival function.

Example

SURVIVAL TABLE = NOARREST MOSFREE BY TREATMNT(1,3)
  /STATUS = ARREST (1) FOR NOARREST
  /STATUS = PRISON (1) FOR MOSFREE
  /INTERVAL = THRU 24 BY 3
  /PLOTS (SURVIVAL,HAZARD) = MOSFREE.
  • Separate life tables are produced for each of the survival variables (NOARREST and MOSFREE) for each of the three values of the control variable TREATMNT.
  • PLOTS produces plots of the cumulative survival distribution and the hazard rate for MOSFREE for the three values of TREATMNT (even though TREATMNT is not included on the PLOTS specification).
  • Because plots are requested only for the survival variable MOSFREE, no plots are generated for the variable NOARREST.