[R] "7:9, 12:14" in dataframe to c(7:9, 12:14)

[Petr Pikal]

Hi

I knew I encountered it somewhere. Looking into my archives gave me 
an answer of similar question by Prof.Ripley

So here you are

df[eval(parse(text=paste("c(",df2[2,"g"], ")"))),]

?eval
?parse

HTH
Petr



On 1 Jan 2006 at 23:27, Mikkel Grum wrote:

Date sent:      	Sun, 1 Jan 2006 23:27:00 -0800 (PST)
From:           	Mikkel Grum <mi2kelgrum at yahoo.com>
To:             	r-help at stat.math.ethz.ch
Subject:        	[R] "7:9, 12:14" in dataframe to c(7:9, 12:14)

> I want to do something like df[df$b %in% df2[i, 2], ] 
> where df$b is a numeric vector and df2[i, 2] is a
> factor with 
> levels like "7:9, 12:14". For example:
> 
> a <- c(paste("A", 1:10, sep = ""), paste("B", 1:10,
> sep = ""))
> b <- 1:20
> df <- as.data.frame(cbind(a, b))
> df$b <- as.numeric(levels(df$b))[as.integer(df$b)]
> 
> f <- c("X", "Y", "Z")
> g <- c("1:6", "7:9, 12:14", "18")
> df2 <- as.data.frame(cbind(f, g))
> 
> i <- 2
> df[df$b %in% df2[i, 2], ] # or
> df[df$b %in% levels(df2)[as.integer(df2[i, 2])], ] #
> this is the closest I've got
> 
> The results I want is given by 
> > df[df$b %in% c(7:9, 12:14), ]
>     a  b
> 7  A7  7
> 8  A8  8
> 9  A9  9
> 12 B2 12
> 13 B3 13
> 14 B4 14
> 
> Can it be done?
> 
> Mikkel Grum
> 
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Petr Pikal
petr.pikal at precheza.cz