[R] R-help: grep in for loop using index - doesn't work

[baptiste auguie]

Hi,

your example is quite messy (neither reproducible or minimal). I think  
you could try the following,


> mdf <- data.frame(1:3)
> names(mdf) <- "147"
>
> i <- 147
>
> mdf[ as.character(i) ]


Hope this helps,

baptiste


On 11 Mar 2009, at 22:34, Mohan Singh wrote:

> Hi everyone
>
>
>
>  I am trying to use grep in a for loop to compare a string value. It  
> works
> if I use the actual index value but when I use the for loop index, it
> doesn't work. Any suggestions plz.
>
>
>
> Here is the code:
>
>
>
> data <- read.table(file="Sigmoid.csv", head=FALSE, sep=",");
>
>
>
> c1 <- data$V1
>
> c2 <- data$V2
>
> c3 <- data$V3
>
>
>
> c1data <- data.frame(c1);
>
> c2data <- data.frame(c2);
>
> c3data <- data.frame(c3);
>
>
>
> #this works
>
> p <- grep("QueryItem",c1data["147",],value=FALSE,fixed=FALSE)
>
> print(p) # print 1
>
>
>
> #doesn't work
>
> i<-147
>
> p1 <- grep("QueryItem",c1data["i",],value=FALSE,fixed=FALSE)
>
> print(p1) # prints 0
>
>
>
> for(i in 137:270) {
>
>  print(i)
>
>  p <- grep("QueryItem",c1data["i",],value=FALSE,fixed=FALSE)
>
>  p2 <- p
>
>  print(p2)
>
>  if(length(p)>0) { print(p) }
>
> }
>
>
>
>
> 	[[alternative HTML version deleted]]
>
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_____________________________

Baptiste Auguié

School of Physics
University of Exeter
Stocker Road,
Exeter, Devon,
EX4 4QL, UK

Phone: +44 1392 264187

http://newton.ex.ac.uk/research/emag