The stan version is in form of major.minor.patch; the
first version is 1.0.0, indicating major version 1, minor version
0 and patch level 0. Functionality only changes with minor versions
and backward compatibility will only be affected by major versions.
Usage
stan_version()
Arguments
Value
A character string giving the version of Stan used in this version of RStan.
References
The Stan Development Team
Stan Modeling Language User's Guide and Reference Manual.
http://mc-stan.org/.