convert list without same component length to matrix

Hi,
You can also use:
sapply(l,`[`,1:4)
#???? [,1] [,2] [,3] [,4] [,5]
#[1,]??? 1??? 3??? 4??? 2??? 3
#[2,]??? 2??? 4??? 2??? 4??? 5
#[3,]??? 3??? 5??? 5??? 6??? 7
#[4,]??? 7??? 6??? 7??? 3??? 2
A.K.



----- Original Message -----
From: D. Rizopoulos <d.rizopoulos at erasmusmc.nl>
To: Al Ehan <aehan3616 at gmail.com>
Cc: "r-help at r-project.org" <r-help at r-project.org>
Sent: Thursday, November 1, 2012 4:19 AM
Subject: Re: [R] convert list without same component length to matrix

try this:

l <- list(c(1,2,3,7), c(3,4,5,6,3), c(4,2,5,7), c(2,4,6,3,2), c(3,5,7,2))

sapply(l, head, 4)


I hope it helps.

Best,
Dimitris

Hi,

I have this lame question. I want to convert a list (each with varies in
length) to matrix with same row length by eliminating vectors outside the
needed range.
For example:

l<-list(NULL)
l[[1]]=1,2,3.7
l[[2]]=3,4,5,6,3
l[[3]]=4,2,5,7
l[[4]]=2,4,6,3,2
l[[5]]=3,5,7,2


#so say I want to only have 4 rows and 5 column in my matrix (or
data.frame) and eliminating the 5th index value in l[[2]] and l[[4]]
#what is the simplest code would be? I actually have hundreds of the list
components.

thanks

??? [[alternative HTML version deleted]]

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Dimitris Rizopoulos
Assistant Professor
Department of Biostatistics
Erasmus University Medical Center

Address: PO Box 2040, 3000 CA Rotterdam, the Netherlands
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Fax: +31/(0)10/7043014
Web: http://www.erasmusmc.nl/biostatistiek/
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and provide commented, minimal, self-contained, reproducible code.