check is a generic function that tests the validity of a given
object.
Usage
check(object, ...)
Arguments
object
an object to be tested for validity.
...
further arguments to be passed to the particular
dispatched function.
Details
check tests if a given object meets the formal requirements of
being a valid object of its class. If the test fails, additional
warnings should be provided, giving some information why the test failed.
Value
returns TRUE if object passes the validity test for the
specific class and FALSE otherwise.
Note
R's dispatching mechanism determines the class of a given object
and then calls the function check.<class-name>. If no specific
check function is found, check.default is called. The
function check.default does not make much sense, for the
purpose of check is to test the validity for a specific
class. Hence, check.default simply returns FALSE
together with a warning message that no specific
check.<class-name> function was found.
The dispatching mechanism has immediately two consequences:
a class specific check routine need not to check
whether the object belongs to the class itself, because if it would
not, the function would not have been called.
if no specific check routine is found, the result for a
call of check will be FALSE, since in this case the
default function is called which will return FALSE in any case.