Tools
Software
The SPEI R library allows computing the SPEI and includes a set of additional functionalities and options.
It can be obtained from the Comprehensive R Archive Network, CRAN. See more info and check the latest developments in the package’s GitHub page 
.
A standalone software has been developed, too, although the code is no longer maintained so the R library is recommended for most users. The C source code and binaries can be found at:
