Error message in sjSDM if pytorch not available

[florianhartig]

Hi, I just tried this out, if you run

com = simulate_SDM(env = 3L, species = 5L, sites = 100L)
model = sjSDM(Y = com$response,env = com$env_weights, iter = 10L)

you without pytorch (luckily, I can do this, as I still haven't updated), I get

 Error in reticulate::py_is_null_xptr(fa) : object 'fa' not found 
3.
reticulate::py_is_null_xptr(fa) at utils.R#84
2.
check_module() at sjSDM.R#58
1.
sjSDM(Y = com$response, env = com$env_weights, iter = 10L) 

whereas a good error message would say "pytorch not installed". I would just do the startup check also in sjSDM to check if the requirements are there.

[MaximilianPi]

> library(sjSDM)
PyTorch not found
1) Use install_sjSDM() to install Pytorch and conda automatically
2) Installation trouble shooting guide: ?installation_help
3) If 1) and 2) did not help, please create an issue on github (see ?install_diagnostic) 
> com = simulate_SDM(env = 3L, species = 5L, sites = 100L)
> 
> model = sjSDM(Y = com$response,env = com$env_weights, iter = 10L)
PyTorch not found
1) Use install_sjSDM() to install Pytorch and conda automatically
2) Installation trouble shooting guide: ?installation_help
3) If 1) and 2) did not help, please create an issue on github (see ?install_diagnostic) 
 Error: PyTorch not installed