MATLAB将每日数据的3D数组分割为每月细分

Question

I have a 1437x159x1253 large matrix (let's call it A) of daily sea ice data for a little over 2 years. I need to write a code that takes the daily data from each month and does mean(A, 3) on it. So basically, 1253 is the t in days. If I start from January, I need to do mean(A,3) of the first 31 days, then the mean(A,3) of February, the next 28 or 29 days. Because the days alternate between 31 and 30 (and 28 or 29 for February), I don't know how to write a code to do this. I can do it manually, but that would take a while.

Thanks!

Answer 1

You can initialize an array containing the number of days in each month, Mon = [31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31] using boolean to check whether it's a leap year (to set Mon(2) = 29 ). The number of days will help you index each month appropriately, using a loop like:

index=1;
for i=1:12
  average = mean(A(:,:,index:(index+Mon(i)-1),3);
  index = index+M(i);     % Starting location of the next month
end