thresholding data based on z-score

Hi All,

I'm attempting to threshold my data using their z-score values. However, it's not clear to me how I am meant to get actual z-score values if the zscore function in matlab give me a matrix where the columns are the values 1SD away when the mean is centered at 0. How could I threshold data to identify values with a z-score of 2 when the zscore function seems to give a matrix where all values have a z-score of 1. I might be reading the matrix incorrectly. CouldI please get some help with this?

Best,

Christiane

[the cyclist]

Are you able to upload a *.mat file with your input?

[Christiane Voufo]

Yes, but i could also insert the line of code that I'm trying to understnad here.

zData = zscore(data);

This is what you meant right? Just wanted to see the code?

[Christiane Voufo]

I'm not sure I understood you question otherwise.

[Christiane Voufo]

Alright, turns out I was overthinking things. I was able to understand the matrix generated with some help from a lab member.

Answer 1

[Image Analyst]

Try this, assuming a 1-D signal:

zScores = zscore(signal)
% Get indexes where zScores > 2
indexes = zScores > 2;
signalWithZMoreThan2 = signal(indexes);

[Christiane Voufo]

This is the answer that I got from a lab mate, not too long ago. Thank you for the input!!