Hello,
Try this:
idx<-sapply(file,function(x) all(unique(x)==1))
file[!idx]
#? V2 V3 V4 V6 V7 V8 V9
#1? 0? 2? 2? 1? 5? 1? 1
#2? 0? 2? 2? 1? 5? 1? 1
#3? 0? 2? 2? 2? 5? 2? 2
#4? 0? 2? 2? 1? 5? 1? 1
#5? 0? 2? 2? 0? 5? 0? 2
#6? 0? 2? 2? 1? 5? 1? 0
A.K.
----- Original Message -----
From: Kate Dresh <dreshkate at gmail.com>
To: r-help at r-project.org
Cc:
Sent: Friday, August 24, 2012 8:11 PM
Subject: [R] remove column
*Hi all,*
I'm trying to filter a file through the columns. This file below is a
example of my data frame. My true data frame has seven hundred thousand
columns and 500 hundred lines. I need to identify and to remove all columns
that all elements equal a number 1. In this my case, columns were deleted
are number 1,5 and 10.
file <-read.table(text="
1? 0? 2? 2? 1? 1? 5? 1? 1? 1
1? 0? 2? 2? 1? 1? 5? 1? 1? 1
1? 0? 2? 2? 1? 2? 5? 2? 2? 1
1? 0? 2? 2? 1 1? 5? 1? 1? 1
1? 0 2? 2? 1? 0? 5? 0? 2? 1
1? 0? 2 2? 1? 1? 5? 1? 0? 1
",sep="",header=FALSE)
the result after the filter will be
0? 2? 2? 1? 5? 1? 1
0? 2? 2? 1? 5? 1? 1
0? 2? 2? 2? 5? 2? 2
0? 2? 2? 1? 5? 1? 1
0? 2? 2? 0? 5? 0? 2
0? 2? 2? 1? 5? 1? 0
I used this commands idlength<-sapply(file,function(x) length(unique(x))
),
but came an error message:
caught segfault ***
address 0x4, cause 'memory not mapped'
*My question: is it possible to remove the all columns from above file
to *achieve* the desired result?*
* *
* **Thank you for help*
Kate Dresh
??? [[alternative HTML version deleted]]
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