R help - Jan 2010 - Is there a quicker way to drop a data frame column than setting it to NULL?

If I want to drop columns x, y, z from dataframe df, is there a better
alternative to

df$x = NULL
df$y = NULL
df$z = NULL

There are sufficiently many columns remaining to make 

df = subset(df, select = c(a,b,c,d[etc]))

cumbersome.

Thank you.
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Dimitri Shvorob wrote:
> If I want to drop columns x, y, z from dataframe df, is there a better
> alternative to
> 
> df$x = NULL
> df$y = NULL
> df$z = NULL
> 
> There are sufficiently many columns remaining to make 
> 
> df = subset(df, select = c(a,b,c,d[etc]))
> 
> cumbersome.
You can use subset with the select argument specifying
which variables to omit:

df = subset(df, select = !names(df) %in% c('x', 'y',
'z'))

or just

df[!names(df) %in% c('x', 'y', 'z')]

  -Peter Ehlers
> 
> Thank you.
-- 
Peter Ehlers
University of Calgary

Try:

subset(df, select = - c(x, y, z))

On Sun, Jan 24, 2010 at 6:58 AM, Dimitri Shvorob
<dimitri.shvorob at gmail.com> wrote:
>
> If I want to drop columns x, y, z from dataframe df, is there a better
> alternative to
>
> df$x = NULL
> df$y = NULL
> df$z = NULL
>
> There are sufficiently many columns remaining to make
>
> df = subset(df, select = c(a,b,c,d[etc]))
>
> cumbersome.
>
> Thank you.
> --
> View this message in context:
http://n4.nabble.com/Is-there-a-quicker-way-to-drop-a-data-frame-column-than-setting-it-to-NULL-tp1288617p1288617.html
> Sent from the R help mailing list archive at Nabble.com.
>
> ______________________________________________
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> PLEASE do read the posting guide
http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
>

Hello,

You can always use

df <- subset( df, select = -c(x, y, z) )

Best regards,

Carlos J. Gil Bellosta
http://www.datanalytics.com

Dimitri Shvorob wrote:
> If I want to drop columns x, y, z from dataframe df, is there a better
> alternative to
> 
> df$x = NULL
> df$y = NULL
> df$z = NULL
> 
> There are sufficiently many columns remaining to make 
> 
> df = subset(df, select = c(a,b,c,d[etc]))
> 
> cumbersome.
> 
> Thank you.