On Wed, 28 Jan 2004, "Hüsing, Johannes" wrote:
> > From: Prof Brian Ripley [mailto:[EMAIL PROTECTED]
> > On Wed, 28 Jan 2004, "Hüsing, Johannes" wrote:
> > > ?apply for more info. You'll want to know about apply if
> > > you want to avoid loops (which is a good approach).
> >
> > Unfortunately ap
)
[1] 3 2 3
Levels: 1 2 3 4 5 6
Sean
- Original Message -
From: "Sundar Dorai-Raj" <[EMAIL PROTECTED]>
To: "R-help" <[EMAIL PROTECTED]>
Sent: Tuesday, January 27, 2004 3:00 PM
Subject: [R] distance between two matrices
> Hi all,
>Say I have a matrix A
You can try and see if knn1() in the `class' package (part of the VR bundle)
can handle the job in one shot. If not, just do it in chunks of B. For
your example:
> id <- 1:nrow(A)
> knn1(A, B, id)
[1] 3 2 3
Levels: 1 2 3 4 5 6
(I believe it returns factor, but that can easily be converted back
On Wed, 28 Jan 2004, "Hüsing, Johannes" wrote:
> > Hi all,
> >Say I have a matrix A with dimension m x 2 and matrix B with
> > dimension n x 2. I would like to find the row in A that is closest to
> > the each row in B. Here's an example (using a loop):
> >
> > set.seed(1)
> > A <- matrix(r
> From: Prof Brian Ripley [mailto:[EMAIL PROTECTED]
> On Wed, 28 Jan 2004, "Hüsing, Johannes" wrote:
> > ?apply for more info. You'll want to know about apply if
> > you want to avoid loops (which is a good approach).
>
> Unfortunately apply() is a wrapper for a for() loop, so will
> not help muc
Sundar,
Have a look at "knn1" from package "class".
As I understand what you want is
as.integer( knn1(train=A, test=B, cl=1:nrow(A)) )
Best regards
Jens Oehlschlägel
> Say I have a matrix A with dimension m x 2 and matrix B with
> dimension n x 2. I would like to find the row in A that
> Hi all,
>Say I have a matrix A with dimension m x 2 and matrix B with
> dimension n x 2. I would like to find the row in A that is closest to
> the each row in B. Here's an example (using a loop):
>
> set.seed(1)
> A <- matrix(runif(12), 6, 2) # 6 x 2
> B <- matrix(runif(6), 3, 2) # 3 x 2
Thanks to Prof. Ripley, Jens, Roger, and Sean. knn1 is exactly what I'm
looking for.
Thanks again,
Sundar
Prof Brian Ripley wrote:
Sounds like knn classification. See function knn1 in package class.
knn(A, B, 1:nrow(A))
gives the same answers as your loop code, and is just a carefully tuned
On Tue, 27 Jan 2004, Sundar Dorai-Raj wrote:
> Hi all,
>Say I have a matrix A with dimension m x 2 and matrix B with
> dimension n x 2. I would like to find the row in A that is closest to
> the each row in B. Here's an example (using a loop):
>
> set.seed(1)
> A <- matrix(runif(12), 6, 2)
Hi all,
Say I have a matrix A with dimension m x 2 and matrix B with
dimension n x 2. I would like to find the row in A that is closest to
the each row in B. Here's an example (using a loop):
set.seed(1)
A <- matrix(runif(12), 6, 2) # 6 x 2
B <- matrix(runif(6), 3, 2) # 3 x 2
m <- vector("num
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