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Differentiating regions

As a follow up to the previous post, check out how Chung-chieh Shan applied regions to a seemingly unrelated problem. His post begins by explaining how automatic (numerical) partial differentiation can be implemented, and goes on to show how to use regions to avoid mixing-up the variables being differentiated.

By Ehud Lamm at 2008-08-08 19:44 | Fun | Functional | Type Theory | other blogs | 5383 reads

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Dead link

Unfortunately the link is not working for me. Does anyone know of a working copy?

By Watson Ladd at Tue, 2008-08-12 15:28 | login or register to post comments

Cache

Hopefully that's just a temporary hiccup. In the meantime, here's a Google cache of the post.

By James Iry at Tue, 2008-08-12 15:38 | login or register to post comments

Nice

Nice. This allows code to be written in a much more direct style, albeit at the cost of having to wrap many numeric values in "lifts", which might get tedious pretty quickly.

(Terminology note: this technique is relevant to forward-mode automatic differentiation. There is another mode (reverse) which is quite distinct, and has very different complexity properties.)

By Barak A. Pearlmutter at Mon, 2008-08-18 21:54 | login or register to post comments