next up previous contents
Next: WFDB_getspf Up: Special Input Modes Previous: WFDB_getifreq   Contents


WFDB_setgvmode

Usage: WFDB_setgvmode(MODE);  
Input: MODE: (string) either 'WFDB_LOWRES' (default) or 'WFDB_HIGHRES'.  

Set the mode used by WFDB_getvec when reading a multi-frequency record. If MODE is 'WFDB_LOWRES', WFDB_getvec decimates oversampled signals. If MODE is 'WFDB_HIGHRES', WFDB_getvec interpolates signals sampled at a lower frequency (repeating the last sample value).

Example: Signal 0 is sampled using 100 Hz and signal 1 using 200Hz. With WFDB_LOWRES, WFDB_getvec returns samples using 100 Hz and signal 1 is decimated from 200 Hz to 100 Hz. With WFDB_HIGHRES, WFDB_getvec returns samples using 200 Hz and signal 0 is interpolated from 100 Hz to 200 Hz.

WFDB_setgvmode also affects how annotations are read and written. If WFDB_setgvmode('WFDB_HIGHRES') is invoked before using any of WFDB_annopen, WFDB_getvec, WFDB_sampfreq, WFDB_strtim, or WFDB_timstr, then all time data (including the time attributes of annotations read by WFDB_getann or written by WFDB_putann) visible to the application are in units of the high-resolution sampling intervals. (Otherwise, time data are in units of frame intervals.)


next up previous contents
Next: WFDB_getspf Up: Special Input Modes Previous: WFDB_getifreq   Contents
George B. Moody 2005-06-02