Time-series data

Hi everybody,

I have a set of time series data and I have to check if the average values are within the range for a certain amount of time (for example if the parameter X is in the range for 2 minutes).

Is there a matlab function that allows me to do that?

Thank you for your time!

[Bob Thompson]

mean() will calculate an average for you.

You can use an if statement to determine if the values is within a certain range.

if average > 1 & average <= 3;

[George1990]

Yes but my problem is to evaluate the mean over time (data are given in seconds over time)

[Bob Thompson]

Are you saying you want a series of mean values, similar to an RMS? Or are you looking for a running average?

[George1990]

I want a series of mean value and check wether they are in range(fixed values) of not. How do you do that? thank you for your help

Answer 1

[Bob Thompson]

The 'simplest' way to do a series of mean values is to use a for loop with the mean function.

nmean = 50; % Number of values you would like to average at a time
for i = 1:2*length(data)/nmean
    average(i) = mean(data((i-1)*nmean/2:(i-1)*nmean/2+nmean));
end

You may run into an issue with index exceeding matrix dimensions near the end of your data set. If this happens, just reduce the maximum i value by changing the bounds of the loop. If you are not sure how to do that look up the basics of a for loop here.