3.6. Get Events

The example will show how to get values associated with an event. We will perform the following steps:

• get RR intervals and the postion of the QRS-complexes

• plot the tachogram of the measurement

rasch@rasch:~> octave
GNU Octave, version 2.1.50 (i686-pc-linux-gnu).
...

octave:1> ra=ra_lib_init
ra = 145018424
octave:2> meas=ra_meas_open(ra, '/home/rasch/ecgs/AT011030_rdi.ART', 0)
meas = 145245184
octave:3> eva=ra_eval_get_def(meas)
eva = 145612904
octave:4> prop_rri=ra_prop_get_by_name(eva, 'rri')
prop_rri = 145667632
octave:5> rri=ra_ev_get_values(prop_rri, 0, -1); 
octave:6> whos rri

*** local user variables:

prot  type                       rows   cols  name
====  ====                       ====   ====  ====
 rwd  matrix                        1   1807  rri

octave:7> prop_qrs=ra_prop_get_by_name(eva, 'qrs-pos')
prop_qrs = 145613912
octave:8> qrs_pos=ra_ev_get_values(prop_qrs, 0, -1);
octave:9> whos qrs_pos

*** local user variables:

prot  type                       rows   cols  name
====  ====                       ====   ====  ====
 rwd  matrix                        1   1807  qrs_pos

octave:10> samplerate=ra_meas_get_info(meas, 'max_samplerate')
samplerate = 1600
octave:11> x=(qrs_pos/samplerate) / 60;
octave:12> plot(x, rri)
octave:13>

Figure 3-2 shows a screenshot of Octave after performing the above steps.