Can WAVE edit signal files?

WAVE itself doesn't do this, but certain kinds of signal file editing are easy to do using snip from WAVE 's Analyze panel. A common requirement is to remove unwanted data from the beginning or end of a record. To do this, simply mark the segment to be retained using the `<' and `>' markers, then click on \ovalbox{\rule[-.3mm]{0cm}{2.5mm}\small\sf ~Extract segment~}.

If your record contains unwanted signals, remove them from the Signal list before extracting the segment. You can also rearrange the order of signals within the signal list if you wish.

Note that this operation does not modify the original record; rather, the desired portions of the record are copied to create a new record. If you wish to copy a set of annotations as well as data from signal files, be sure to load the annotation file for the original record into WAVE before extracting the segment. (See snip(1), in the WFDB Applications Guide, if you need to copy two or more sets of annotations.)

To join two or more records end-to-end, use wfdbcollate to create a multi-segment record. wfdbcollate writes a special header file for the new record, but does not copy or modify the signal or header files of the original records; it will, however, write new annotation files on request, since the WFDB library does not support multi-segment annotation sets. The records to be joined must be ordinary (not multi-segment) records. If necessary, xform can be used to rewrite a multi-segment record as an ordinary record. See wfdbcollate(1), in the WFDB Applications Guide, for further information.

More complex editing of signal files, such as splicing segments or modifying individual samples, can be done by converting the signals to text form using rdsamp (accessible from WAVE via the \ovalbox{\rule[-.3mm]{0cm}{2.5mm}\small\sf ~List samples~} button in the Analyze window), editing the text as required, and converting the edited text to a signal file using wrsamp (see wrsamp(1), in the WFDB Applications Guide, for details).

George B. Moody (george@mit.edu)
2014-03-13