Message-ID: <61bkcv4hqepnl5evk8eubbvudqekfhdadv@4ax.com>
Date: 2003-05-20T15:58:36Z
From: Duncan Murdoch
Subject: Extending %*%
In-Reply-To: <te2jcvkqn8uq9it881386oqi1n4j8ncakh@4ax.com>
On Mon, 19 May 2003 21:56:24 -0400, you wrote in message
<te2jcvkqn8uq9it881386oqi1n4j8ncakh@4ax.com>:
>I have lists of matrices stored in various ways. I'd like to extend
>%*% to work on these. Is this possible, or should I create my own new
>operator?
In answer to my own question: yes, it's possible, using the S4
classes and methods. It would look something like this:
setClass("special", representation(m = "list"))
setMethod("%*%",
signature(x = "special", y="special"),
function(x,y)
new("special",
m = mapply("%*%", x@m, y@m, SIMPLIFY=FALSE))
)
A1 <- A2 <- A3 <- B1 <- B2 <- B3 <- diag(c(2,3))
A <- new("special", m = list(A1, A2, A3))
B <- new("special", m = list(A1, A2, A3))
A %*% B
(Thanks Uwe for the compact expression to implement the method!)
Duncan Murdoch