[R] Removing rows if certain elements are found in character string

[arun]

Hi,
I didn't think about the situation where D comes before T.  I changed my code a little to accommodate that.

dat2<-read.table(text="
1  0000000000D0000000000000000000000000000000000000 0.007368;
2  0000000000d0000000000000000000000000000000000000 0.002456;
3  000000000T00000000000000000000000000000000000000 0.007368;
4  000000000DT0000000000000000000000000000000000000 0.007368;
5  000000000T00000000000000000000000000000000000000 0.002456;
6  000000000Td0000000000000000000000000000000000000 0.002456;
7  00000000T000000000000000000000000000000000000000 0.007368;
8  00000000T0D0000000000000000000000000000000000000 0.007368;
9  00000000T000000000000000000000000000000000000000 0.002456;
10 00000000T0d0000000000000000000000000000000000000 0.002456;
",sep="",header=FALSE)
colnames(dat2)<-c("num","Ch", "count")
dat2[grepl("0T|0Td|0TD",dat2$Ch),]
num                                               Ch     count
3    3 000000000T00000000000000000000000000000000000000 0.007368;
5    5 000000000T00000000000000000000000000000000000000 0.002456;
6    6 000000000Td0000000000000000000000000000000000000 0.002456;
7    7 00000000T000000000000000000000000000000000000000 0.007368;
8    8 00000000T0D0000000000000000000000000000000000000 0.007368;
9    9 00000000T000000000000000000000000000000000000000 0.002456;
10  10 00000000T0d0000000000000000000000000000000000000 0.002456;

A.K.





----- Original Message -----
From: Rui Barradas <ruipbarradas at sapo.pt>
To: Claudia Penaloza <claudiapenaloza at gmail.com>
Cc: r-help at r-project.org
Sent: Monday, July 2, 2012 7:24 PM
Subject: Re: [R] Removing rows if certain elements are found in character string

Hello,

Try regular expressions instead.
In this data.frame, I've changed row nr.4 to have a row with 'D' as 
first non-zero character.

dd <- read.table(text="
ch     count
1  0000000000D0000000000000000000000000000000000000 0.007368
2  0000000000d0000000000000000000000000000000000000 0.002456
3  000000000T00000000000000000000000000000000000000 0.007368
4  000000000DT0000000000000000000000000000000000000 0.007368
5  000000000T00000000000000000000000000000000000000 0.002456
6  000000000Td0000000000000000000000000000000000000 0.002456
7  00000000T000000000000000000000000000000000000000 0.007368
8  00000000T0D0000000000000000000000000000000000000 0.007368
9  00000000T000000000000000000000000000000000000000 0.002456
10 00000000T0d0000000000000000000000000000000000000 0.002456
", header=TRUE)
dd

i1 <- grepl("^([0D]|[0d])*$", dd$ch)
i2 <- grepl("^0*[Dd]", dd$ch)

dd[!i1, ]
dd[!i2, ]
dd[!(i1 | i2), ]


Hope this helps,

Rui Barradas

Em 02-07-2012 23:48, Claudia Penaloza escreveu:
> I would like to remove rows from the following data frame (df) if there are
> only two specific elements found in the df$ch character string (I want to
> remove rows with only "0" & "D" or "0" & "d"). Alternatively, I would like
> to remove rows if the first non-zero element is "D" or "d".
>
>
>                                                   ch     count
> 1  0000000000D0000000000000000000000000000000000000 0.007368;
> 2  0000000000d0000000000000000000000000000000000000 0.002456;
> 3  000000000T00000000000000000000000000000000000000 0.007368;
> 4  000000000TD0000000000000000000000000000000000000 0.007368;
> 5  000000000T00000000000000000000000000000000000000 0.002456;
> 6  000000000Td0000000000000000000000000000000000000 0.002456;
> 7  00000000T000000000000000000000000000000000000000 0.007368;
> 8  00000000T0D0000000000000000000000000000000000000 0.007368;
> 9  00000000T000000000000000000000000000000000000000 0.002456;
> 10 00000000T0d0000000000000000000000000000000000000 0.002456;
>
>
> I tried the following but it doesn't work if there is more than one
> character per string:
>
>> df <- df[!df$ch %in% c("0","D"),]
>> df <- df[!df$ch %in% c("0","d"),]
>
> Any help greatly appreciated,
> Claudia
>
>     [[alternative HTML version deleted]]
>
> ______________________________________________
> R-help at r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
>

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