# Rackpropagator - automatic differentiation in Racket **URL:** \ **Category:** Show & Tell\ **Created:** [April 2, 2022, 4:23pm UTC](https://racket.discourse.group/t/rackpropagator-automatic-differentiation-in-racket/844 "2022-04-02T16:23:29Z")\ **Posts on this page:** 2\ **Page:** 1
**Author:** ![OliverS](https://avatars.discourse-cdn.com/v4/letter/o/8edcca/32.png) [@OliverS](https://racket.discourse.group/u/OliverS)\ **Post date:** [April 2, 2022, 4:23pm UTC](https://racket.discourse.group/t/rackpropagator-automatic-differentiation-in-racket/844/1 "2022-04-02T16:23:29Z")
I've been working on an [automatic differentiation](https://en.wikipedia.org/wiki/Automatic_differentiation) library recently and thought I'd share the current work-in-progress. I've had fun writing it and have learned a lot about the Racket macro system in the process! - [Rackpropagator on GitHub](https://github.com/ots22/rackpropagator) - [docs](https://ots22.github.io/rackpropagator/) - `raco pkg install rackpropagator` It provides so-called 'reverse mode' AD, implemented as syntax transformation. A function definition (written in a subset of Racket) can be macro-transfomed into a function that also computes its gradient. See the docs for some examples and references. The output it produces can be quite inefficient at the moment, along with a few other limitations. I'm currently thinking about how to improve this. Also, the build on the package server seems to be failing, although I'm not sure why. ---
**Author:** ![dannypsnl](https://yyz2.discourse-cdn.com/free1/user_avatar/racket.discourse.group/dannypsnl/32/917_2.png) [@dannypsnl](https://racket.discourse.group/u/dannypsnl)\ **Post date:** [April 2, 2022, 4:44pm UTC](https://racket.discourse.group/t/rackpropagator-automatic-differentiation-in-racket/844/2 "2022-04-02T16:44:08Z")
seems like not package's problem: ```scheme raco setup: making: /rackpropagator-lib/rackpropagator raco setup: in /rackpropagator-lib/rackpropagator Killed ```