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wrann - write a WFDB annotation file


wrann -r record -a annotator


wrann translates its standard input into an annotation file. The format of wrann input should be that produced by rdann(1) using its default settings. Specifically, the pipeline
   rdann -r record -a iann -f 0 | wrann -r record -a oann

is guaranteed to produce an identical copy of the annotation file read by rdann, provided that the aux fields of the annotations do not contain embedded nulls.

The usual application for wrann is as an aid to annotation file editing: an annotation file may be translated into ASCII format using rdann, edited using a text editor, and then translated back into annotation file format using wrann.

Note the alternate format selected by rdann’s -x option is incompatible with wrann.

Versions of wrann included in version 10.4.20 (and later versions) of the WFDB Software Package set the time fields of output annotations to match the times in the first column of input if those times appear to be absolute times (beginning with ’[’). Otherwise, as in previous versions, wrann matches the sample numbers given in the second column of input. This capability can be used in a pipeline with rdann to copy a set of annotations between two records that overlap in time, even if their starting times or sampling frequencies are different.


It may be necessary to set and export the shell variable WFDB (see setwfdb(1) ).

See Also

rdann(1) , setwfdb(1)


George B. Moody (


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Updated 8 March 2019