title: RHRV package - loading episodes - TIME DOMAIN analysis (not frequency analysis)
body: <p>I have a question regarding the RHRV package, specifically regarding analysing within episodes.
  It is my understanding that in order to perform analyzes inside and outside of episodes, you have to interpolate the heart rate series first; however, I do not want to calculate frequency analysis with the SplitHRbyEpisodes/ AnalyzeHRbyEpisodes function, but time-domain analysis. To be more specific, I would like to calculate SDNN, RMSSD and pNN50 inside and outside the specified episodes. I tried to change the mean in &gt; result = AnalyzeHRbyEpisodes(hrv.wfdb, Tag =&quot;Apnea&quot;, &quot;mean&quot;) to e.g. SDNN, but this is not working. Could anyone tell me whether it is possible to calculate these time domain analysis inside the episodes? Unfortunately, there are no answers to this in the manual. Thank you very much in advance!</p>