Printing has no effect on the model’s log probability function. Its sole purpose is the side effect (i.e., an effect not represented in a return value) of arguments being printed to whatever the standard output stream is connected to (e.g., the terminal in command-line Stan or the R console in RStan).
(T1 x1,..., TN xN)
Print the values denoted by the arguments x1 through xN on the output message stream. There are no spaces between items in the print, but a line feed (LF; Unicode U+000A; C++ literal
'\n') is inserted at
the end of the printed line. The types
TN can be any of
Stan’s built-in numerical types or double quoted strings of characters
Available since 2.1