Cmdstanr reduce sum case study, but: unused argument (threads = TRUE)

Following Reduce Sum: A Minimal Example but getting:

> cmdstan_version()
[1] "2.23.0"
> logistic1 <- cmdstan_model("logistic1.stan", threads = TRUE)
Error in self$compile(...) : unused argument (threads = TRUE)

I can compile without threads = TRUE just fine.

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we have refactored the way users enable threading in the last few days.

The signature has changed to

logistic1 <- cmdstan_model("logistic1.stan", cpp_options = list(stan_threads = TRUE))

Its also updated in the case study, but it has changed basically yesterday. So you may be looking at an old version.

The way you use it should however print a warning, not an error, I am working on that.
I apologize, cmdstanr is still in development mode, so things sometimes break. We try not to break it intentionally :)


thank you !!!

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thanks again !

I refreshed the case study Reduce Sum: A Minimal Example and reinstalled cmdstanr but cores and chains still does not work, so maybe I have an older version still ?

> library(cmdstanr)
This is cmdstanr version
- Online documentation and vignettes at
- CmdStan path set to: /home/shira-rstudio/.cmdstanr/cmdstan-2.23.0
- Use set_cmdstan_path() to change the path

I tried my local machine and a cluster of cores, different values for num_chains, num_cores, num_threads (see my question about how to set these here), but I rarely get speed-up, and never anywhere close to the 2.7 speed-up in the case study.

I must be doing something silly ! thanks again for your help.

Since I can’t get any speed-up in CmdStanR, it might it be worth trying to replicate the case study in regular CmdStan instead ?

I followed Getting Started with CmdStan, used stan_rdump(names(redcard_data), "") in RStudio, and then in the terminal:

make ~/Documents/logistic0
make ~/Documents/logistic1
~/Documents/logistic0 sample data file=~/Documents/
~/Documents/logistic1 sample data file=~/Documents/

These compile and sample. But how do I modify to set cores and threads, following the Reduce Sum: A Minimal Example case study ? How can I time things ?

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in CmdStan, you need to run the make command to compile everything with threading on - if you’re using the CmdStan 2.23 release, the easiest way to do this is:

make clean-all
make STAN_THREADS=TRUE my_model

to time things, use the linux time command -

time my_model sample yada yada yada

there’s no control for cores - since CmdStan runs a single chain, with threading on, it’ll use all available cores - @wds15 or @rok_cesnovar - is this correct?

That is correct.