MATLAB: Average multiple cells in the same lat and lon

averageduplicatelatitudelongitudematrix manipulationstandard deviation

Hello,
I have a 3422×5 (double) numeric matrix A = [Latitude Longitude Biomass lower_boundary upper_boundary]
the lower and upper boundary represent depth
I want to be able to average the biomass across any bins that are in the same exact latitude and longitude. There are several measurements that are in the same lat and lon, so I want to be able to get just one data point for each lat and lon. I also want to be able to calculate the standard deviation of each of those calculations in a different column to keep track of the statistics. Along with this, I would like to keep the lower and upper boundary columns intact with respect to the new, averaged dataset. The duplicated bins all have the same correlated upper and lower boundary
What would be the most efficient way of accomplishing this? I am attaching the matlab file for better reference as to what I am talking about
Any help is appreciated.
Thanks,
Melissa

Best Answer

% Remove nans
idxKeep = ~any(isnan(A(:,1:3)),2);
Akeep = A(idxKeep,:);
% Unique combinations of lat/lon and where they are
[ulatlon,~,idx] = unique(Akeep(:,1:2),'rows');
% Mean of each combination
meanBm = accumarray(idx,Akeep(:,3),[],@mean);
% Combine unique lat/lon combos and meanBm into table
T = table(ulatlon,meanBm,'VariableNames',{'LatLon','MeanBioMass'});
% Show Results
disp(T)
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