>> WFDB_strann('p') ans = 24
The description is:
>> WFDB_anndesc(24) ans = P-wave peak
Create the two annotations:
>> ANN = WFDB_Annotation(2) ANN = 1x2 struct array with fields: time anntyp subtyp chan num aux >> ANN(1).time = 315; >> ANN(1).anntyp = 24; >> ANN(1).aux = 'First P-wave'; >> ANN(2).time = 610; >> ANN(2).anntyp = 24; >> ANN(2).aux = 'Second P-wave';
Now create an annotator structure:
>> A = WFDB_Anninfo(1) A = name: 'a1' stat: 'WFDB_READ' >> A.name = 'p'; >> A.stat = 'WFDB_WRITE';
Create an empty annotation file to hold the annotations:
>> WFDB_annopen('100s', A)
Write the annotations:
>> WFDB_putann(0, ANN)
The first argument of WFDB_putann is the output annotator number. Since we are writing only one annotation file, its annotator number is 0.
Close all open files:
>> WFDB_wfdbquit
The new annotation file, 100s.p, will be located in MATLAB's current directory. The result may be verified using WAVE, which can be called from MATLAB using:
>> !wave -r 100s -a p &
(Remember the !-sign to call system functions from MATLAB and the &-sign to run WAVE as a background process; depending on your setup, using & may cause an error, however, and you may need to run WAVE as a foreground process without the final '&' in the command.)
An elaborated version of this example is provided in the examples directory of the WFDB_tools package (look for example3.m).