I have a vector where the end is padded with NaN. How to index where real numbers end and where NaNs begin

Dear Matlab,

Attached is sample data with a row vector.

The row vector is an averaged EEG signal and starts with real numbers and at some point, the real numbers end and the NaNs begin. I want to find where (what column) the NaNs start so that I can trim the NaNs and just have a vector of real number values. Please help/advice.

Thanks in advance!

Joanne

Answer 1

[the cyclist]

Here are two methods of finding the last index that is not NaN:

load("C.mat","c")

% Method 1
lastNonNanIndex1 = sum(not(isnan(c)))

lastNonNanIndex1 = 185934

% Method 2
lastNonNanIndex2 = find(not(isnan(c)),1,"last")

lastNonNanIndex2 = 185934

But if you don't need the index, and just want to trim it, then

c(isnan(c)) = []; % Trims the NaN values from the vector

numel(c) % Show the length of the new vector

ans = 185934

[Joanne Hall]

I tried the last one - worked like a charm - thank you so much!!!