struct casereader *casereader_project (struct casereader *,
const struct subcase *);
struct casereader *casereader_project_1 (struct casereader *, int column);
+struct casereader *casereader_select (struct casereader *,
+ casenumber first, casenumber last,
+ casenumber by);
+
/* A function which creates a numberic value from an existing case */
typedef double new_value_func (const struct ccase *, casenumber, void *);