Creates or tests for objects of type
|object to be coerced or tested.|
|further arguments passed to or from other methods.|
as.numeric is a generic function, but methods must be written for
as.double, which it calls.
is.numeric is generic: you can write methods to handle specific classes of objects, see InternalMethods.
Note that factors are false for
is.numeric since there is a
numeric creates a real vector of the specified length. The elements of the vector are all equal to
as.numeric attempts to coerce its argument to a numeric type (either integer or real).
as.numeric for factors yields the codes underlying the factor levels, not the numeric representation of the labels.
has no single precision data type. All real numbers are stored in double precision format.
Becker, R. A., Chambers, J. M. and Wilks, A. R. (1988) The New S Language. Wadsworth \& Brooks/Cole.