Calculating the average value for each year

I'm a student learning matlab and I'm having trouble calculating averages. The first six columns of the array "data2" are the datevector values; the 7th column contains average temperature for each month, from 1895 to 2006 (as shown in the attached "Final project - FortStJames arrays" file). I'm trying to calculate the average temperature for each year.

I think I need two loops (one for the year and another one to loop over all the temperature values). I'm not sure which should be the outer and inner loops. I'm also not sure what indices to use in this part of the loop

temp_avg(i,1) = mean( data2(,) );

Here is my code:

% data2 contains the datevector and a 7th column for the temp
data2 = my_datevectors;
data2(:,7) = temp4; 

temp_avg = []; % we'll fill in the values
% Use a loop to compute the average temp for each year
for i = 1:length(data2) % length(data2) is # of observations
    for j = 1895:2006 % j is the year
    temp_avg(i,1) = mean( data2(,) );
    j = j+1;
    end % end of loop2
end % end of loop1

Here's the link to my DAT file: https://www.dropbox.com/s/nsbhrhgqo440e94/FortStJames_v22.dat?dl=0

Thanks

Answer 1

[Andrei Bobrov]

I use Import Data from MATLAB menu (Home):

[yy,~,c] = unique(FortStJamesv22{18:end,'Year'});
out = [yy, accumarray(c,FortStJamesv22{18:end,'MeanTempC'},[],@nanmean)];