I need get the average value of a KF, based on the unique combinations of two characteristics.
material and color are two characteristics.
The base data is
m1 c1 $
m1 c2 $
m1 c3 $
m2 c4 $
m2 c1 $
Now there is 5 unique combination of mtl and color. but when I average the $ it is averaging it with dividing the $ sum by 4 as there is only 4 unique colors (with except.aggr. for color char). How can I make it to consider all the unique combinations of mtl and color and get the average even with duplicate colors?