Hi,
A function calculates the absolute difference between the two largest values
of each row of a matrix, as shown in the following example code:
cx - matrix(runif(15),5)
cy - t( apply(cx, 1, order, decreasing=TRUE) )
cz - rep(0, nrow(cx))
for( i in 1:nrow(cx) ) cz[i] - abs(diff(cx[i,
On Tue, 2007-01-09 at 16:10 -0500, Christos Hatzis wrote:
Hi,
A function calculates the absolute difference between the two largest values
of each row of a matrix, as shown in the following example code:
cx - matrix(runif(15),5)
cy - t( apply(cx, 1, order, decreasing=TRUE) )
cz -
Thanks, Marc.
This is what I was trying to do but could not get it to work.
-Christos
-Original Message-
From: Marc Schwartz [mailto:[EMAIL PROTECTED]
Sent: Tuesday, January 09, 2007 4:32 PM
To: [EMAIL PROTECTED]
Cc: 'R-help'
Subject: Re: [R] A vectorization question
On Tue, 2007-01
Welcome Christos.
Note that my first example can actually be simplified to:
apply(mat, 1, function(x) -diff(sort(x, decreasing = TRUE)[1:2]))
Since we really just need to negate the difference, rather than take the
abs().
The advantage of this approach is that the two max values will always
again.
-Christos
-Original Message-
From: Marc Schwartz [mailto:[EMAIL PROTECTED]
Sent: Tuesday, January 09, 2007 5:07 PM
To: [EMAIL PROTECTED]
Cc: 'R-help'
Subject: RE: [R] A vectorization question
Welcome Christos.
Note that my first example can actually be simplified to:
apply(mat
