R help - Dec 2011 - matching using "which"

Dear R users,

I have a very simple query.

I am using the following command, which should give me row no. for the
matching colnames. It works well for matching the colnames but if there is
no column matching it gives me outcome as integer(0) which I am not able to
use in further calculation. It would be very helpful to have some insight.
*
*
*> b <- which(colnames(data)%in%c("X.","X"))*
*> b*
*integer(0)*
*> b>0*
*logical(0)*
*>b<- data[,-b]  # does not work properly*
*
*
Regards
Vikram

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Hi. Here is one approach:

if (length(b)>0) data[,-b] else data

Andrija

On Thu, Dec 8, 2011 at 1:25 PM, Vikram Bahure
<economics.vikram@gmail.com>wrote:
> Dear R users,
>
> I have a very simple query.
>
> I am using the following command, which should give me row no. for the
> matching colnames. It works well for matching the colnames but if there is
> no column matching it gives me outcome as integer(0) which I am not able to
> use in further calculation. It would be very helpful to have some insight.
> *
> *
> *> b <- which(colnames(data)%in%c("X.","X"))*
> *> b*
> *integer(0)*
> *> b>0*
> *logical(0)*
> *>b<- data[,-b]  # does not work properly*
> *
> *
> Regards
> Vikram
>
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>
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