fast code

tmp <- data.frame(x1=c(3,4,6.5,20,35), x2=c(3.1,4.2,5,24,38) )
attach(tmp)

tmp$x3 <- sapply( x2, function(val) max(x1[x1<val]) )

tmp

-----Original Message-----
From: Pantelis Andreou [mailto:pan at mathstat.dal.ca]
Sent: Friday, December 06, 2002 1:21 PM
To: Janusz Kawczak
Cc: r-help at stat.math.ethz.ch
Subject: Re: [R] fast code


Hello again,
here is an example
x1      x2      x3
3       3.1     3
4       4.2     4
6.5     5	4
20      24	20
35      38	35


On Fri, 6 Dec 2002, Janusz Kawczak wrote:

Example would help!

On Fri, 6 Dec 2002, Pantelis Andreou wrote:

Date: Fri, 6 Dec 2002 14:09:22 -0400 (AST)
From: Pantelis Andreou <pan at mathstat.dal.ca>
To: r-help at stat.math.ethz.ch
Subject: [R] fast code

Hello again,
I think I made a mistake discribing the problem.
I have two column vectors x1 and x2 both in increasing order.
I need a column vector x3 such that
the jth entry of x3 is the maximum ith entry x1 which is smaller
than the jth entry of x2.
Regards,
Pantelis