Average of different rows depending on the last column value

I have a 1000x5 matrix suppose wherein, first column is customer_id and last column is customer_desc which will be 1,2,3, or 4 for all the customers and columns 2 till 4 are data of which I need to take the mean depending on the value of customer_desc. Ex the output needs to be like this: -

Customer_desc   Average col2  Average Col3  Average col4
----------------------------------------------------------------
  1           0.235742555  0.325659159  0.283776929
  2           0.511820228  0.311237444  0.394172541
  3           0.254775313  0.352126843  0.306672852
  4           0.365448276  0.345090639  0.354142646

I can do this using a for loop but I wanted to vectorize the calculation. Also I need to calculate the average of a customer_desc/ sum(average(other customer_desc)) as well. Any suggestions/ideas would be helpful.

Answer 1

[Image Analyst]

If you have the Statistics and Machine Learning Toolbox, you can use grpstats().

means = grpstats(t, 'Customer_desc');

[Hariprasad]

I'm sorry, we do not have the Statistics and Machine Learning Toolbox. I have only Matlab and Database Toolbox.

[Hariprasad]

Hi Image Analyst, I got the solution after searching.

% Group by customer_desc
[un,~,pos] = unique(data(:,end),'rows');

% Produce row, col subs 
[col,row] = meshgrid(1:3,pos); % (1:3) seems to be num of columns 
                                 as below in reshape(data(:,2:4)[],1)

% Accumulate 
Averages = [un accumarray([row(:), col(:)], reshape(data(:,2:4),[],1),[],@nanmean)];

Thanks for the help though. Need to work on the next step now.