is.loaded
returns a logical value stating if the given object is
currently loaded into S-PLUS.
The symbol functions return the symbol that would be associated with a name.
is.loaded(symbol) symbol.C(name) symbol.For(name) symbol.S(name)
symbol.C
or
symbol.For
.
is.loaded
function returns a logical value: it is
TRUE
if the symbol is found
in the S-PLUS symbol table and
FALSE
otherwise.
The
symbol.C
function returns the symbol that would be produced by a C function named
name
.
The
symbol.For
function
returns the symbol that would be produced by a Fortran subroutine
named
name
.
The
symbol.S
function
returns the symbol that would be produced by an old-S function
named
name
.
These functions are mainly useful for writing S-PLUS functions that will
automatically dynamically link code if it is not loaded already.
The
symbol.S
function is no longer useful.
if(!is.loaded(symbol.C("mbol"))) dyn.open("/usr/mabel/mbol.so") .C("mbol",as.double(x),as.integer(length(x)))