NAME

dsisubset.h - DATASET_METHOD subset type

SYNOPSIS

Given an existing DATASET, one can define a new subset of the first data set. The actual subset is determined by a user specified vector of indices. This is useful for incremental techniques applied to huge amounts of data.

#include <dsisubset.h>

DSM_ISUBSET *dsm_isubset(DATASET *dset,
      unsigned *index,
      unsigned len);

void dsm_destroy_isubset(DSM_ISUBSET *isubset);

DESCRIPTION

Type Declarations

The following types are defined in the header file dsisubset.h.

DSM_ISUBSET

typedef struct DSM_ISUBSET {
  DATASET *dset;
  unsigned *index;
  unsigned len;
} DSM_ISUBSET;

A DSM_ISUBSET specifies how to reference a subset of the data in dset. If you were to ask for the i'th pattern of the DATASET wrapped by this structure, in reality you would get the index[i] pattern of dset. Also, in the subset, you can only reference len patterns, so the values in these fields should make sense for {dset.}

Function Definitions

The following function prototypes are given in the header file dsisubset.h.

DSM_ISUBSET *dsm_isubset(DATASET *dset,
      unsigned *index,
      unsigned len);

Allocates a new isubset, and fills up the appropriate fields of the structure.

void dsm_destroy_isubset(DSM_ISUBSET *isubset);

Free up any memory that was allocated with the allocation routine. The original DATASET that is passed to dsm_subset() is left intact; hence, it is your job to free them up.

AUTHOR

Gary William Flake (gary.flake@usa.net).

SEE ALSO

dsmethod(3), and dataset(3).