two for Nested Loops

How i can sum the third column to get the average over each 24 values of the second coloumn?

[KL]

sounds more like making daily sum from hourly data. Use a timetable!

[ahmad Saad]

KL

Yes, it is the daily sum from hourly data. but How the time table can be used?

Answer 1

[Jos (10584)]

Your question is a little unclear. Do you want to sum all values of the third row when the second row equals 0, equals 1, etc, so you end up with 24 summed values? That is easy:

A = xlsread('average24');
S = accumarray(A(:,2)+1, A(:,3), [24,1], @mean)
% S(k) is the average of all values of A(:,3) when A(:,2) equals (k-1)

[Jos (10584)]

you want the average, answer corrected! :)

Answer 2

[Jan]

Maybe

A = xlsread('average24');

% Average over blocks of 24 values:
S1 = mean(reshape(A(:, 3), 24, []), 1);

% Or average over all values belonging to 0, 1, 2, ...:
S2 = mean(reshape(A(:, 3), 24, []), 2);

Answer 3

[KL]

An example with timetable,

EDITED

%import data
data = readtable('actual data.txt');
%create a proper datetime column
data.Timestamp = datetime(cell2mat(data{:,[1 2]}),'InputFormat','yyyy.MM.ddHH:mm');
%keep only datetime and measurements
data = data(:, [end 3]);
%create timetable
TT = table2timetable(data(:,2),'rowtimes',data.Timestamp);
%calculate daily mean
TT_mean = retime(TT,'daily','mean');

Answer 4

[ahmad Saad]

I'm very grateful for all. i'll check the answers and feek back

the answers are really helpfull

thanks again

Answer 5

[ahmad Saad]

This the actual data

from 1/10/2017 to 30/11/2017 the output should have 61 values

[KL]

check my edited answer!

[ahmad Saad]

First, thanks for your help

it seems that there is a error with respect to second line, i get: variable index exceeds table dimension

(i put the data in an excel file)

[KL]

The answer I gave you works on your text file. I tested it before posting it here!

This is the output

 TT_mean =
  61×1 timetable
       Time        Var3 
    __________    ______

    2017-10-01    9383.2
    2017-10-02    9388.9
    2017-10-03    9420.8
    2017-10-04    9449.3
    2017-10-05      9463
    2017-10-06    9456.5
    2017-10-07    9406.2
    2017-10-08    9364.3
    2017-10-09    9386.4
    2017-10-10    9440.3
    ...

[ahmad Saad]

KL

OK

i'll try again and feedback; thanks for your kind attention

Answer 6

[ahmad Saad]

Birdman

deep thanks, it works fine, thanks : Birdman