Why the function mean does not return only one plot rather than 31?

Dear Coders,

I have an issue I am trying to obtain only one profile per month, so I want to make a day-average per month, but when I apply the function "mean" it does not calculate the row by row average, it gives me back the same 31 days, please, tell me what it is wrong in this simple operation. I share the code below.

clear all
close all

REE=xlsread('REE_perfiles2020.xlsx',1,'a3:h8786');
NDias=REE(:,1); %%%%%Número de días en total

aP=REE(:,4); %
ai=reshape(aP,[24, 366]); 

E=ai(:,[1:31]);
ME=mean(E,24);
plot(ME)
legend
size(ME)

Answer 1

[Jan]

mean(E, 24) calculates the mean over the 24th dimension. Remember that in Matlab all arrays are assume to have and arbitrary number of trailing dimensions of the size 1:

x = [2, 3; 4, 5]
x(1,2, 1,1,1,1,1,1,1,1,1,1,1,1,1,1)   % Valid!

You want to bild the mean over the 2nd dimension, if I understand you correctly. Then:

mean(E, 2)

[Tony Castillo]

Thanks for your answer!.