Follow-up on Implementation of custom layer in Lux

[ghost]

Hi,

This question is a follow up to the issue #376.

A quick follow up on mat = reshape(y, 3, 3) syntax.
How would it handle a symmetric matrix if I supply 6 independent components?

I know from symmetry that
mat=[y[1] y[2] y[3]; y[2] y[4] y[5]; y[3] y[5] y[6]]. Would this be acceptable for AD?

Additionally, how can I check is AD will compute the gradients?

Best Regards

[avik-pal]

The default AD (Zygote) will not be able to differentiate that code. You will have to define a custom rrule. See https://juliadiff.org/ChainRulesCore.jl/dev/rule_author/which_functions_need_rules.html fro a good reference.