Calculating The standardized precipitation evapotranspiration index (SPEI) and standardized precipitation index (SPI) in STATA

[Lemekezani Chilora]

I am working on a study where I want to look at the effects of climate change using the standardized precipitation evapotranspiration index and standardized precipitation index. I would like to know if there is a command which can generate these indices in STATA? If there is, can you please assist me? If there isn't, how can I generate the indices in STATA?

[Nick Cox]

These key terms are sufficiently precise that a Google should find any public files.

The documents I've found on Googling suggest that the calculation is fairly complicated but free programs exist to run it.

[Lemekezani Chilora]

I tried Googling, but all I could find were programs for R and how to do the SPI in excel. So I thought there is a program in STATA as well.

[Nick Cox]

I don't really have any information you don't have, but I would be very surprised at an implementation in Stata. I work on hydrological and meteorological data some of the time, and i watch the Stata community, and I don't see many people working in the same field. (I had not heard of these indexes before today.)