Drexel dragonThe Math ForumDonate to the Math Forum



Search All of the Math Forum:

Views expressed in these public forums are not endorsed by Drexel University or The Math Forum.


Math Forum » Discussions » Software » comp.soft-sys.matlab

Topic: time rounding issues
Replies: 4   Last Post: Aug 20, 2014 4:51 PM

Advanced Search

Back to Topic List Back to Topic List Jump to Tree View Jump to Tree View   Messages: [ Previous | Next ]
Travis

Posts: 182
Registered: 1/31/08
time rounding issues
Posted: Aug 20, 2014 1:50 PM
  Click to see the message monospaced in plain text Plain Text   Click to reply to this topic Reply

I have a large amount of data that is timestamped by the instruments recording it. When processing the data I need a complete time series, but there are times when there are gaps in the record that I need to fill. I have converted the timestring to MATLAB time and created another full time variable using...

time = t(1):1/48:t(end); %half hour data intervals

When I use the intersect command though I do not get the desired result; not all the times are the same (even though when I put them back to datestrings they are identical).

I set up a quick check...

a(:,1) = 1:1/48:100;
b = 1;
for i = 2:4753; %length of a
b = [b;addtodate(b(i-1),30,'minute')];
end

c = find(a ~= b); %3168 results.

Is this a rounding issue with the 1/48? Is there a way to do this without using a for-loop and the addtodate command (I have seen the code slow down a lot when working with larger datasets)?



Point your RSS reader here for a feed of the latest messages in this topic.

[Privacy Policy] [Terms of Use]

© Drexel University 1994-2014. All Rights Reserved.
The Math Forum is a research and educational enterprise of the Drexel University School of Education.