`nimbleHMC()` error: "must set `buildDerivs = TRUE` when building model" when the model is created using `readBUGSmodel()`

[pehkawn]

According to the Nimble user guide, automatic differentiation (AD) is needed when using HMC (nimbleHMC::nimbleHMC()).

When building a model using nimbleModel(), AD can be enabled by setting the function argument buildDerivs = TRUE. However, when building the model using readBUGSmodel(), there's seemingly no option for enabling AD.

Consequentially, I get the error message:

Error: must set buildDerivs = TRUE when building model

when running nimbleHMC() on my BUGS model.

~I was therefore wondering if there's another way of enabling AD, when reading in a BUGS model file?~

As a feature suggestion, it would be an improvement if buildDerivs were to be added to available options in either nimbleHMC() or readBUGSmodel().

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[Edit:]

I just realized I can enable AD for all models by setting nimbleOptions(buildModelDerivs = TRUE). However, I do not know the implications of having AD globally enabled. Still, it would be a nice feature to enable AD for the model only.

[danielturek]

@perrydv It seems reasonable to add this buildDerivs argument to readBUGSmodel.

I'd be happy to make this quick change, but let me know what you think.

[paciorek]

@danielturek @perrydv looks like we never resolved this. I'm going to add the argument to readBUGSmodel unless there are objections.

[danielturek]

@paciorek Agreed, thank you.