>>>>> "Robin" == Robin Hankin <[EMAIL PROTECTED]>
>>>>> on Thu, 28 Jun 2007 13:38:32 +0100 writes:
Robin> I am having difficulty using signature(). I have one
Robin> virtual class (onion) and two nonvirtual classes
Robin> (quaternion and octonion). containing onion.
Robin> I want to define three distinct sets of arithmetic
Robin> operations: one for onion-onion, one for onion-real,
Robin> and one for real-onion [this is more computationally
Robin> efficient than coercing reals to onions and then
Robin> using onion-onion operations].
Robin> Executing the following code gives an error [R-2.5.0]
Robin> at the first call to setMethod():
Robin> Error in match.call(fun, fcall) : unused argument(s)
Robin> (o1 = "onion", o2 = "onion")
Robin> Why is this,
you are not free to call your arguments whatever you like:
The generic function prescribes the signature,
in the case of Arith,
its (e1, e2)
Robin> and what would the List suggest is Best Practice here?
use the correct signature :-)
Regards,
Martin
Robin> setClass("onion", representation = "VIRTUAL" )
Robin> setClass("quaternion", representation =
Robin> representation(x="matrix"), prototype =
Robin> list(x=matrix(numeric(),0,4)), contains = "onion" )
Robin> setClass("octonion", representation =
Robin> representation(x="matrix"), prototype =
Robin> list(x=matrix(numeric(),0,8)), contains = "onion" )
Robin> ".onion.onion.arith" <- function(o1,o2){stop("OO not
Robin> implemented")} ".onion.real.arith" <-
Robin> function(o,r){stop("OR not implemented")}
Robin> ".real.onion.arith" <- function(r,o){stop("RO not
Robin> implemented")}
Robin> setMethod("Arith", signature (o1="onion",o2="onion"
Robin> ), .onion.onion.arith) setMethod("Arith",
Robin> signature(o="onion",r="ANY" ), .onion.real.arith)
Robin> setMethod("Arith", signature(r="ANY",o="onion" ),
Robin> .real.onion.arith)
Robin> -- Robin Hankin Uncertainty Analyst National
Robin> Oceanography Centre, Southampton European Way,
Robin> Southampton SO14 3ZH, UK tel 023-8059-7743
Robin> ______________________________________________
Robin> R-devel@r-project.org mailing list
Robin> https://stat.ethz.ch/mailman/listinfo/r-devel
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