Re: incremental from accumulated values

[Andrew Wittenberg <andyw@xxxxxxxxxxxxxxxxxxxx>]

On Mon, 8 Oct 2001, Bill Gustafson wrote:
> I want something like:
>    let prcpinc = prcpacc-prcpacc[l=`l-1`]
> The problem is that `l-1` does not evaulate to a single scaler since it
> changes with every time.

Hi Bill,

The "shift" (@SHF) transformation (User's Guide Ch. 3, Sec. 2.4.10) will
do what you need:

let prcpinc = prcpacc-prcpacc[l=@shf:-1]

Cheers,

Andrew

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Andrew Wittenberg          Program in Atmospheric and Oceanic Sciences
andyw@splash.princeton.edu                        Princeton University
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