Several ways to do this, including findgroups/splitapply, groupsummary, and varfun:
>> XYZ = [ ...
1 1800 1.5
2 1900 1.4
3 2100 3
3 1900 1.1
1 1900 0.8
2 2700 1.2
1 1800 2];
>> T = array2table(XYZ,'VariableNames',{'x' 'y' 'z'})
T =
7×3 table
x y z
_ ____ ___
1 1800 1.5
2 1900 1.4
3 2100 3
3 1900 1.1
1 1900 0.8
2 2700 1.2
1 1800 2
>> varfun(@mean,T,'GroupingVariables',{'x' 'y'})
ans =
6×4 table
x y GroupCount mean_z
_ ____ __________ ______
1 1800 2 1.75
1 1900 1 0.8
2 1900 1 1.4
2 2700 1 1.2
3 1900 1 1.1
3 2100 1 3
