How to truncate a time series to 20.000 points?

Dear colleagues,

I am using ann2rr() to generate RR time series from beat annotation files from Physionet.org. I would like to truncate ALL obtainned time series up to a value say of 20.000 points. How could I implement it for various time series? Can it be done simultaneously for many times series? If yes, how? I have never worked with time before and therefore I would need a very understable explanation, if possible! Many thanks for your patience and guidance. Kind regards, Massilon

[KSSV]

It is 20 points or value of 20?

[dpb]

I'm guessing it's 20,000 points; the dot is thousands punctuation not decimal position.

[Massilon Toniolo da Silva]

Hi everyone,

I am sorry for the confusion1

I meant 20 thousands.

Kind regards,

Massilon

Answer 1

[dpb]

Don't know how you're getting the data, but if it is just a chosen length in number of elements (points), then simply

data=importdata(...);  % just example way to load a data file
NKeep=20000;           % the size of series wanted
data=data(1:NKeep,:);  % keep that many rows; all columns

Incorporate such logic in a function that does the reading of the data given the filename(s) and desired length to make it a general facility.