The user may use the SPLIT FILE command (see SPLIT FILE in PSPP Users Guide) to select a set of variables on which to split the active dataset into groups of cases to be analyzed independently in each statistical procedure. The set of split variables is stored as part of the dictionary, although the effect on data analysis is implemented by each individual statistical procedure.
Split variables may be numeric or short or long string variables.
The most useful functions for split variables are those to retrieve
them. Even these functions are rarely useful directly: for the
purpose of breaking cases into groups based on the values of the split
variables, it is usually easier to use
Returns a pointer to an array of pointers to split variables. If and only if there are no split variables, returns a null pointer. The caller must not modify or free the returned array.
Returns the number of split variables.
The following functions are also available for working with split variables.
Sets dict’s split variables to the cnt variables in vars. If cnt is 0, then dict will not have any split variables. The caller retains ownership of vars.
Removes var, which must be a variable in dict, from dict’s split of split variables.