N [OF CASES] num_of_cases [ESTIMATED].

N OF CASES limits the number of cases processed by any procedures that follow it in the command stream. N OF CASES 100, for example, tells PSPP to disregard all cases after the first 100.

When N OF CASES is specified after TEMPORARY, it affects only the next procedure (see TEMPORARY). Otherwise, cases beyond the limit specified are not processed by any later procedure.

If the limit specified on N OF CASES is greater than the number of cases in the active dataset, it has no effect.

When N OF CASES is used along with SAMPLE or SELECT IF, the case limit is applied to the cases obtained after sampling or case selection, regardless of how N OF CASES is placed relative to SAMPLE or SELECT IF in the command file. Thus, the commands N OF CASES 100 and SAMPLE .5 both randomly sample approximately half of the active dataset’s cases, then select the first 100 of those sampled, regardless of their order in the command file.

N OF CASES with the ESTIMATED keyword gives an estimated number of cases before DATA LIST or another command to read in data. ESTIMATED never limits the number of cases processed by procedures. PSPP currently does not make use of case count estimates.