R help - Jun 2009 - subsetting data frame using a vector of column names / values

Hello

I have a data frame d with columns "var1", "var2",
"var3"

Then I have two vectors:
columns <- c("var2", "var3")
values <- c(0, 1)


Is there a compact way to subset the data frame
using these two vectors and get the result equivalent to:

select (d, var2==0 & var3==1)  ?

Thank You

Blazej

Try this:

subset(d, eval(parse(text = paste(paste(columns, values, sep = "=="),
collapse = " & "))))

On Wed, Jun 24, 2009 at 9:16 AM, Blazej Krzeminski <bkrzem@gmail.com>
wrote:
> Hello
>
> I have a data frame d with columns "var1", "var2",
"var3"
>
> Then I have two vectors:
> columns <- c("var2", "var3")
> values <- c(0, 1)
>
>
> Is there a compact way to subset the data frame
> using these two vectors and get the result equivalent to:
>
> select (d, var2==0 & var3==1)  ?
>
> Thank You
>
> Blazej
>
> ______________________________________________
> R-help@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.
>


-- 
Henrique Dallazuanna
Curitiba-Paraná-Brasil
25° 25' 40" S 49° 16' 22" O

	[[alternative HTML version deleted]]

Hi

r-help-bounces at r-project.org napsal dne 24.06.2009 14:16:15:
> Hello
> 
> I have a data frame d with columns "var1", "var2",
"var3"
> 
> Then I have two vectors:
> columns <- c("var2", "var3")
> values <- c(0, 1)
> 
> 
> Is there a compact way to subset the data frame
> using these two vectors and get the result equivalent to:
> 
> select (d, var2==0 & var3==1)  ?
The first part, to select columns seems to be straightforward

d[,columns]

the second part is a bit trickier e.g.

ind = which(rowSums(mapply("%in%", d[,columns], values))>1)
d[ind, columns]

shall give you the result

Regards
Petr

> 
> Thank You
> 
> Blazej
> 
> ______________________________________________
> 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.