Hi Pradip,

It is easier to use subset().  Check ?subset for some examples and pay
special attention to the "select" parameter.  By the way, do not call your data
"df" as it is already a function.

Best,
Jorge.-


On Sat, Nov 24, 2012 at 1:55 PM, Muhuri, Pradip (SAMHSA/CBHSQ) <> wrote:

>
> Hello,
>
> I have two very basic questions (console attached):
>
> 1) What am I getting an error message for  # 5 and # 7 ?
> 2) How to fix the code?
>
> I would appreciate receiving your help.
>
> Thanks,
>
> Pradip Muhuri
>
>
>
> ###### Reproducible Example  #####
>
> N <- 100
> set.seed(13)
> df<-data.frame(matrix(sample(c(1:10),N, replace=TRUE),ncol=5))
>
> keep_var <- c("X1", "X2")
> drop_var <- c("X3", "X4", "X5")
>
>
> df[df$X1>=8,] [,1:2]                   #1
> df[df$X1>=8,] [,-c(3,4,5)]             #2
> df[df$X1>=8,] [,c(-3,-4,-5)]           #3
> df[df$X1>=8,] [,c("X1", "X2")]         #4
> df[df$X1>=8,] [,-c("X3", "X4", "X5")]  #5  DOES NOT WORK
> df[df$X1>=8,] [,keep_var]              #6
> df[df$X1>=8,] [, !drop_var]            #7   DOES NOT WORK
>
> ______________________________________________
> 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.
>

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