Time Sync Data from two files

Hi,

I have two excel sheets of data from two devices. The first dataset [DATA 1] is a ~2000x5 matrix that had a sampling rate of 1 sample/sec. The second dataset [DATA 2] is a ~300x3 matrix that had a sampling rate of 1 sample/3 sec (actually, the sampling rate is inconsistent and switches between 1 sample/3 sec and 1 sample/4 sec).

I'd like to sync the data such that I retain all of the data points from DATA 1, and DATA 2 is appropriately matched up according to its time. Ideally, there would be empty cells for the 2 or 3 seconds where there is no data from DATA 2.

I thought I'd try to synchronize with timeseries, but that only outputs 'union' timepoint I think. I'd like to keep all of DATA 1 instead of removing the points where there is no intersection. Then, I thought about an ugly nested for loop where I might compare the timepoints in DATA 2 and DATA 1 and insert an empty row of cells into DATA 2 matrix where TIME 1 does not equal TIME 2, but I think that would be a very bad method and was wondering if there is any better method.

Thank you in advance.

Answer 1

[the cyclist]

Do the timestamps in the two files match exactly, or only approximately? If the former, I bet you could use the ismember() function.

[Khanh]

I thought that the time stamps are the same. But when I code:

[tf, loc] = ismember(DATA1(time column), DATA2(time column)), I get no true outputs in the matrix.

so if they're actually not the same, I tried to convert the timestamps into a string format and continue with the ismember function, but that spits out a large matrix that I can't decipher.

[the cyclist]

Tough to diagnose without more info. Would it be possible for you to post a small but representative subset of your data to illustrate what you are trying to do? The ideal is self-contained MATLAB code, with inputs included (so that we can actually run what you have), along with what you hope the output to look like.