The SET PC_SAMPLING command enables the collection of program
    counter sampling data. After you enter the GO command with
    program counter sampling enabled, the Collector samples the
    program counter (PC) every 10 milliseconds and records each
    observed program counter value in the performance data file. You
    can change the sampling interval with the /INTERVAL:n qualifier.

    You must collect stack PC information if you want to use a /MAIN_
    IMAGE, /CUMULATIVE or /STACK_DEPTH qualifier with the PLOT or
    TABULATE command in the Analyzer.