Plot large files with timestamp

2 views (last 30 days)
Ancalagon8
Ancalagon8 on 21 Nov 2018
Edited: Ancalagon8 on 6 Jan 2025
I have a large file and try to load it into MATLAB and plot it with timestamp.
  2 Comments
Jan
Jan on 21 Nov 2018
What is your question?
Ancalagon8
Ancalagon8 on 21 Nov 2018
I need help loading and plotting my large csv file with timestamp.

Sign in to comment.

Answers (1)

Walter Roberson
Walter Roberson on 21 Nov 2018
strcat the first two columns together with a blank between . datetime the result with an InputFormat parameter , which is required for this purpose because datetime cannot figure out fractions of a second by itself .
Now that you have timestamps and values you can prepare to plot . I think your release permitted using datetime as the X axis .
  2 Comments
Walter Roberson
Walter Roberson on 21 Nov 2018
That is more work. Time of day without an attached date is handled by duration objects. In your R2016b release, duration() did not support input as time strings, so to construct the objects it would be necessary to parse the character strings into arrays of numeric values that can then be passed to duration() . It is easier to
dt = datetime( strcat(testdata{:,1}, {' '}, testdata{:,2}), 'inputformat', 'yyyy-MM-dd HH:mm:ss.SSSSSS');
You can always convert those to duration afterwards:
dur = dt - dateshift(dt(1), 'start', 'day');
After which you can plot, such as
plot(dur, testdata{:,3:4})
Walter Roberson
Walter Roberson on 21 Nov 2018
Like you posted,
testdata = read(ds);

Sign in to comment.

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!