MATLAB: Calculating the average value of some variables during each sample time

matrixmatrix array

Hi, I have data that contains one columns for time and some columns for values of some variables the same as following (this is a part of my data):
    A=[ ‘29/07/2014 08:00:00.000’  152 28 2; 
        ‘29/07/2014 08:00:01.000’  100 20 8; 
        ‘29/07/2014 08:00:02.000’  201 45 7; 
        ‘29/07/2014 08:00:03.000’  149 23 6]
First, the start time, finish time and sample time (time interval) are given by user. I want to calculate the average value for each variable during each sample time that user specified. Suppose that user has given the following information: Start time: ‘29/07/2014 08:00:00.000’; Finish time: ‘29/07/2014 08:20:00.000’; Sample time: 5 ;% based on minute. I Finally want to have a set of data as the following:
    F=[‘29/07/2014 08:00:00.000’ X1 Y1 Z1; 
       ‘29/07/2014 08:05:00.000’ X2 Y2 Z2; 
       ‘29/07/2014 08:10:00.000’ X3 Y3 Z3; 
       ‘29/07/2014 08:15:00.000’ X4 Y4 Z4; 
       ‘29/07/2014 08:20:00.000’ X5 Y5 Z5];
That for example X2 is the average of X values between ‘29/07/2014 08:00:00.000’ and ‘29/07/2014 08:05:00.000’ and X3 is the average of X values between ‘29/07/2014 08:05:00.000’ and ‘29/07/2014 08:10:00.000’. Would you please help me how can I do this?

Best Answer

A={ '29/07/2014 08:00:00.000'  152 28 2; 
        '29/07/2014 08:08:01.000'  100 20 8; 
        '29/07/2014 08:12:02.000'  201 45 7; 
          '29/07/2014 08:13:03.000'  149 23 6
          '29/07/2014 08:15:03.000'  149 23 6
          '29/07/2014 08:16:03.000'  149 23 6
          '29/07/2014 08:18:03.000'  149 23 6}
t2 = datenum(2014,7,29,8,(0:5:20)',0);
t1 = datenum(A(:,1),'dd/mm/yyyy HH:MM:SS.FFF');
[~,ii] = histc(t1,[t2;inf]);
B = cell2mat(A(:,2:end));
s = size(B); %  EDIT 
[r,c] = ndgrid(ii,1:s(2));
F = [datevec(t2),accumarray([r(:),c(:)],B(:),[numel(t2),s(2)],@mean)];
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