Hi,
I apologize for this repeat posting, which I first posted yesterday. I would
appreciate any hints on solving this problem:
I have two matrices A (m x 2) and B (n x 2), where m and n are large
integers (on the order of 10^4). I am looking for an efficient way to
create another matrix, W
sage -
From: "Ravi Varadhan" <[EMAIL PROTECTED]>
To:
Sent: Thursday, February 01, 2007 4:10 PM
Subject: [R] Need help writing a faster code
> Hi,
>
>
>
> I apologize for this repeat posting, which I first posted yesterday.
> I would
> appreciate any hints o
Hi
> A <- matrix(runif(10),ncol=2)
> B <- matrix(runif(10),ncol=2)
> g <- function(i4){theta <- atan2( (i4[4]-i4[2]),(i4[3]-i4[1]))
+ return(theta + 2*pi*(theta<0))}
> apply(A,1,function(x){apply(B,1,function(y){g(c(x,y))})})
[,1] [,2] [,3][,4] [,5]
[1,] 1.17
ssage-
From: Dimitris Rizopoulos [mailto:[EMAIL PROTECTED]
Sent: Thursday, February 01, 2007 10:33 AM
To: Ravi Varadhan
Cc: r-help@stat.math.ethz.ch
Subject: Re: [R] Need help writing a faster code
the following seems to be a first improvement:
m <- 2000
n <- 5000
A <- matrix(rnorm(2
Varadhan
Cc: r-help@stat.math.ethz.ch
Subject: Re: [R] Need help writing a faster code
the following seems to be a first improvement:
m <- 2000
n <- 5000
A <- matrix(rnorm(2*m), ncol=2)
B <- matrix(rnorm(2*n), ncol=2)
W1 <- W2 &l
