canCoerce              package:methods              R Documentation

Can an Object be Coerced to a Certain S4 Class?

Description:

     Test if an object can be coerced to a given S4 class. Maybe useful
     inside 'if()' to ensure that calling 'as(object, Class)' will find
     a method.

Usage:

     canCoerce(object, Class)

Arguments:

  object: any R object, typically of a formal S4 class.

   Class: an S4 class (see 'isClass').

Value:

     a scalar logical, 'TRUE' if there is a 'coerce' method (as defined
     by 'setAs', e.g.) for the signature '(from = class(object), to =
     Class)'.

See Also:

     'as', 'setAs', 'selectMethod', 'setClass',

Examples:

     m <- matrix(pi, 2,3)
     canCoerce(m, "numeric") # TRUE
     canCoerce(m, "array")   # TRUE

