Hi folks, Mostly as a heads-up: I just submitted a pull-request for the math/calculus addon which adds hooks, under, NVV forks and fixes some bugs.
You can find it here: https://github.com/jsoftware/math_calculus/pull/9 . Any comments are highly appreciated! My main motivation for messing around with this addon is to: a) Get to a point where I understand the code (mission accomplished, I think); b) Get the add-on to a point where one can apply (p)deriv on anything that makes sense and get a result out of it without falling back to secant approximation. c) On the long term, it would be great if we could get it to do automatic differentiation (https://en.wikipedia.org/wiki/Automatic_differentiation). This would be great for implementing neural networks that do backpropagation, where you'd just have to write a trivial line of J, and automatically get gradients out by simply applying an adverb/conjunction. d) On the even longer term, something like symbolic J, where you can simplify, expand and reduce J verbs as one does with maths in a computer algebra system. Having the machinery to do such manipulations could also let the user convert J code to run on a GPU, via the arrayfire interface, for instance. But this is too far out for me to do in a reasonable amount of time. All help is welcome, especially from people knowing what they're doing :). PS: Raul's pull-request, doing simplification of overly complicated derivatives, is also still hanging at: https://github.com/jsoftware/math_calculus/pull/5/files Best regards, Jan-Pieter ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
