Using Grads to sort data in column/ calculate SPI index

[Cottet, Loic (IFPRI)]

 Dear Colleagues,

 I am new in using your software Grads.

DO you know how I can calculate the SPI index with precipitation data
for a peculiar point?

I have this software Spi_SL_6. exe
It can work but if I sort data in columns.
Do you know how to output my data in column after I did my yearly
averages of precipitation with Grads,

Thank You very much,



Loic Cottet

Research Fellow on Climate Change and Impacts on Agriculture

Under Liangzhi You's Supervising

IFPRI (International Food Policy Research Institute)

Tel. 202 862 4619