I have two variables 'P-idx' and 'Replacing_values'. P_idx is a bigger matrix consisiting of the FID_1 value/s from Replacing_values at different cells. Replacing_values has two fields: FID_1 and Volume. I want to replace the values of the FID_1 in the P_idx with the Volume values of Replacing_values based upon the common FID_1 values. Can anyone please help me how to do this?