How to set a threshold based on the values of an array vector ?

hi experts, I want to set a threshold based on the percentage of values in an array vector(320*1), Thus the value with the highest percentage will be my threshold for future use.

I want to plot the histogram of this array while the Y-axis have the percentage of each value occured in the array vector.

Any help or an ideat about how to set a threshold, i really appreciate it !

[chocho]

load('supgene')
hist(Support_gene);

Answer 1

[Image Analyst]

Use the > operator:

aboveThresholdIndexes = yourSignal > someThresholdValue;  % A logical vector.
% If you want to extract those points:
aboveThreshold = yourSignal(aboveThresholdIndexes);

I leave it up to you to computer someThresholdValue because we don't know exactly what "threshold based on the percentage of values in an array" means. Do you mean like a percentage of 320 (the number of values in the array), or do you somehow want to take into account the values of those elements, in which case cumsum() might help?

[chocho]

Hi Friend, I tried your code and doesn't work.

Undefined function or variable 'someThresholdValue'.

Error in threshold (line 10) aboveThresholdIndexes = Support_gene > someThresholdValue; % A logical vector.

[chocho]

 @Image Analyst Friend, I already share the array vector and you can have a look on it.
There are 320 elements but most of them are repeated, and so,
 I want to see the distributions of these elements and based on their output curve I can pick the cutoff or the threshold, but if you have another idea plz share it with me.

[Image Analyst]

That's because you never defined someThresholdValue. If you need to determine it by looking at the histogram, then call the histogram function:

histogram(yourSignal);

Obviously, just like someThresholdValue, you need to replace yourSignal with the actual name of your variable, and of course you need to have defined it already.

[chocho]

@Image Analyst Friend my goal is to define the threshold, how to define it and still don't know what's it. did you get it ?

 Even histogram(yourSignal); is not working because of my array vector is of type double.