Control over Tracing
DESCRIPTION:
Controls the tracing of functions.
USAGE: 
trace.on(on=T)


std.trace()
std.xtrace()


sys.trace()
OPTIONAL ARGUMENTS:
on:
logical flag used to control whether tracing is activated or not.
VALUE:
sys.trace returns a vector of character strings naming the functions currently being traced.
SIDE EFFECTS:
std.trace and std.xtrace print the call made to the function being traced.

trace.on controls whether tracing is on or off by means of the .Traceon object in the session database.

DETAILS:
Functions std.trace and std.xtrace are the default tracer functions used by trace on entry and exit to the traced function. These standard minimal trace functions just print a message describing the call. You can use these functions as models to create your own tracing functions.
SEE ALSO:
trace , debugger .
EXAMPLES: 
sys.trace() # view which functions are currently traced