Column order in stacking/unstacking

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Hi:

It would help if you named your variables such that alphanumeric ordering
doesn't disturb your variable ordering. Having been burned by this a few
times, I've learned the basics of sprintf() :) Here's your example
revisited, along with an alternative stacking/unstacking display with
package reshape.

library(reshape)
vnames<- paste('X', sprintf('%02d', c(1, 2, 10)), sep = '')

vnames

[1] "X01" "X02" "X10"

<snip>

You can do this a bit more simply with sprintf:

  vnames <- sprintf("%s%02d", "X", c(1, 2, 10))

Peter Ehlers

Dear Dennis and Peter,
Thank you for the suggestions - they work very well with my example data.

I *think* I've got it up and running using my real data (with 2000 columns)
too, with:

sprintf("%s%04d", "X", c(1:2000))

then the stacking/unstacking operations.

Thanks again for the help

Best wishes,
Matthew

-----Original Message-----
From: Peter Ehlers [mailto:ehlers at ucalgary.ca] 
Sent: 12 March 2011 11:09 AM
To: Dennis Murphy
Cc: Matthew Carroll; r-help at r-project.org
Subject: Re: [R] Column order in stacking/unstacking

Hi:

It would help if you named your variables such that alphanumeric ordering
doesn't disturb your variable ordering. Having been burned by this a few
times, I've learned the basics of sprintf() :) Here's your example
revisited, along with an alternative stacking/unstacking display with
package reshape.

library(reshape)
vnames<- paste('X', sprintf('%02d', c(1, 2, 10)), sep = '')

vnames

[1] "X01" "X02" "X10"

<snip>

You can do this a bit more simply with sprintf:

  vnames <- sprintf("%s%02d", "X", c(1, 2, 10))

Peter Ehlers