R help - Jul 2010 - sort file names in numerical order

Hello,

I get some file names by list.files().
These names are in alphabetical order.
I want to change it to logical numeric order.
Example:
> fileNames <- c("A10", "A1", "A2",
"B1", "B2", "B10")
> sort(fileNames)
[1] "A1"  "A10" "A2"  "B1" 
"B10" "B2"
I want to have:
"A1"  "A2" "A10" "B1" "B2"
"B10"

Is this possible?

Kind regards,

Sebastian

library(gtools)
?mixedorder 


--- On Sat, 7/17/10, Sebastian Gibb <lists at sebastiangibb.de> wrote:
> From: Sebastian Gibb <lists at sebastiangibb.de>
> Subject: [R] sort file names in numerical order
> To: r-help at r-project.org
> Received: Saturday, July 17, 2010, 4:31 AM
> Hello,
> 
> I get some file names by list.files().
> These names are in alphabetical order.
> I want to change it to logical numeric order.
> Example:
> > fileNames <- c("A10", "A1", "A2",
"B1", "B2",
> "B10")
> > sort(fileNames)
> [1] "A1"? "A10" "A2"? "B1"?
"B10" "B2"
> I want to have:
> "A1"? "A2" "A10" "B1"
"B2" "B10"
> 
> Is this possible?
> 
> Kind regards,
> 
> Sebastian
> 
> ______________________________________________
> 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.
>

On Sat, Jul 17, 2010 at 4:31 AM, Sebastian Gibb <lists at
sebastiangibb.de> wrote:
> Hello,
>
> I get some file names by list.files().
> These names are in alphabetical order.
> I want to change it to logical numeric order.
> Example:
>> fileNames <- c("A10", "A1", "A2",
"B1", "B2", "B10")
>> sort(fileNames)
> [1] "A1" ?"A10" "A2" ?"B1"
?"B10" "B2"
> I want to have:
> "A1" ?"A2" "A10" "B1"
"B2" "B10"
>
> Is this possible?
>
The code for mixsort which does that type of sorting can be found on this page:

  http://gsubfn.googlecode.com

and gtools has a mixedsort function.

thanks a lot, it works.

you wrote:
> library(gtools)
> ?mixedorder
> 
> --- On Sat, 7/17/10, Sebastian Gibb <lists at sebastiangibb.de>
wrote:
> > From: Sebastian Gibb <lists at sebastiangibb.de>
> > Subject: [R] sort file names in numerical order
> > To: r-help at r-project.org
> > Received: Saturday, July 17, 2010, 4:31 AM
> > Hello,
> > 
> > I get some file names by list.files().
> > These names are in alphabetical order.
> > I want to change it to logical numeric order.
> > 
> > Example:
> > > fileNames <- c("A10", "A1",
"A2", "B1", "B2",
> > 
> > "B10")
> > 
> > > sort(fileNames)
> > 
> > [1] "A1"  "A10" "A2"  "B1" 
"B10" "B2"
> > I want to have:
> > "A1"  "A2" "A10" "B1"
"B2" "B10"
> > 
> > Is this possible?
> > 
> > Kind regards,
> > 
> > Sebastian
> > 
> > ______________________________________________
> > 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.

> I get some file names by list.files().
> These names are in  alphabetical order.
> I want to change it to logical numeric  order.
> Example:
> > fileNames <- c("A10", "A1", "A2",
"B1", "B2",  "B10")
> > sort(fileNames)
> [1] "A1"  "A10" "A2"  "B1"  
"B10" "B2"
> I want to have:
> "A1"  "A2" "A10" "B1"
"B2" "B10"
> 
> Is  this possible?
Greetings.  I see that you've gotten an elegant solution to your problem.
I've appended a poor-man's solution, which I generated more for my own
edification than for yours.

-- Mike


## modified file names, changed to exhibit sorting on letters
fileNames <- c("A10", "B10", "A1",
"A2", "B1", "B2"); fileNames

## use regular expressions to pick off letters, numbers
fnLet <- gsub("(^[^0-9]+).*$", "\\1", fileNames); fnLet
fnNum <- gsub("^[^0-9]+(.*)$", "\\1", fileNames); fnNum

## need to force numeric sorting of the numbers
fnNum <- as.numeric(fnNum)

## find the order of the numbers, for later use in subsetting
fnNumOrd <- order(fnNum); fnNumOrd

## pack all the relevant information into a data frame, then select from that
fnPieces <- data.frame(fnLet, fnNum, fileNames, stringsAsFactors=FALSE);
fnPieces

## partial sort by numbers only (gives new df)
dfPartialSort <- fnPieces[fnNumOrd, ]; dfPartialSort

## find the order of the names, then select from new df with that
fnLetOrd <- order(dfPartialSort[, 1]); fnLetOrd
dfFullSort <- dfPartialSort[fnLetOrd, ]; dfFullSort

## the file names have "gone along for the ride", so pick them off now
sortedFileNames <- dfFullSort$fileNames; sortedFileNames