Use the set_cmdstan_path() function to tell CmdStanR where the
CmdStan installation in located. Once the path has been set,
cmdstan_path() will return the full path to the CmdStan installation and
cmdstan_version() will return the CmdStan version number. See Details
for how to avoid manually setting the path in each R session.
set_cmdstan_path(path = NULL)
cmdstan_path()
cmdstan_version(error_on_NA = TRUE)(string) The full file path to the CmdStan installation. If
NULL (the default) then the path is set to the default path used by
install_cmdstan() if it exists.
(logical) Should an error be thrown if CmdStan is not
found. The default is TRUE. If FALSE, cmdstan_version() returns
NULL.
A string. Either the file path to the CmdStan installation or the CmdStan version number.
CmdStan version string if available. If CmdStan is not found and
error_on_NA is FALSE, cmdstan_version() returns NULL.
Before the package can be used it needs to know where the CmdStan installation is located. When the package is loaded it tries to help automate this to avoid having to manually set the path every session:
If the environment variable "CMDSTAN" exists at load time
then its value will be automatically set as the default path to CmdStan for
the R session. If the environment variable "CMDSTAN" is set, but a valid
CmdStan is not found in the supplied path, the path is treated as a top
folder that contains CmdStan installations. In that case, the CmdStan
installation with the largest version number will be set as the path to
CmdStan for the R session.
If no environment variable is found when loaded but any directory in the
form ".cmdstan/cmdstan-[version]" (e.g., ".cmdstan/cmdstan-2.23.0"),
exists in the user's home directory (Sys.getenv("HOME"), not the current
working directory) then the path to the cmdstan with the largest version
number will be set as the path to CmdStan for the R session. This is the
same as the default directory that install_cmdstan() would use to install
the latest version of CmdStan.
It is always possible to change the path after loading the package using
set_cmdstan_path(path).