I am analyzing some weather data by plotting graphs and looking at trends. The data is being collected by a Campbell Scientific Datalogger CR1000X. Various datapoints are being collected such as air temperature, humidity, leaf temperature, net radiation etc. I still have to do some simple equations to get other answers; like:

Air temp - Leaf Temp = Leaf Temperature Depression

I have to perform these calculations several times and would like a way of automating the process. I just don’t know how to make a proper loop. This is what I have. DATA.LTD is a structure that has all of my values saved in a 48X1 format. The same is true for DATA.HMPlo… and DATA.Canopy…

I have 24 files that I need to perform this calculation on. I also have other calculations I need to perform on these structures.

`DATA.LTD = (DATA.HMPlo_T_Avg - DATA.Canopy_T_Avg);

DATA1.LTD = (DATA1.HMPlo_T_Avg - DATA1.Canopy_T_Avg);

DATA2.LTD = (DATA2.HMPlo_T_Avg - DATA2.Canopy_T_Avg);

DATA3.LTD = (DATA3.HMPlo_T_Avg - DATA3.Canopy_T_Avg);

DATA21.LTD = (DATA21.HMPlo_T_Avg - DATA21.Canopy_T_Avg);

DATA22.LTD = (DATA22.HMPlo_T_Avg - DATA22.Canopy_T_Avg);

DATA23.LTD = (DATA23.HMPlo_T_Avg - DATA23.Canopy_T_Avg);`

How do I create a loop that can perform the math, advance the structure number, and continue until it reaches the end?