In order to calculate a grid cell average of PFT attributes (including what CLM5 now refers to as crop functional types, or CFTs);

1) Calculate the weighted average of your attribute according to PFT. For example, in the input file **surfdata_0.9x1.25_16pfts_Irrig_CMIP6_simyr2000_c170824.nc**** **use the PCT_NAT_PFT variable as weights for the attribute of interest (say, canopy height).

2) Calculate the weighted average of your attribute according to CFT. Again, in **surfdata_0.9x1.25_16pfts_Irrig_CMIP6_simyr2000_c170824.nc** use PCT_CFT as the weights for your attribute of interest.

3) Calculate a weighted average of the outputs of steps 1 and 2 above using the percent area of the grid cell that the crop and natural vegetation land units occupy as weights (PCT_CROP and PCT_NATVEG respectively).

Then you should have a grid cell average of your PFT/CFT attribute.

Thanks to Danica of NCAR for input.