Hi, Simon:

On 2/29/2012 10:04 AM, Simon Urbanek wrote:
On Feb 29, 2012, at 12:37 PM, Spencer Graves wrote:

Hello, All:


      What can people tell me about converting back slashes to forward slashes 
in character strings?


That's it's trivially done with

gsub("\\", "/", x, fixed=TRUE)

Where x is the character string (and I suppose you are aware of it since you 
are using it below).

      It does not work for me.  Consider the following:


> x <- 'c:\Users\'
Error: '\U' used without hex digits in character string starting "c:\U"


This is one reason I needed to use "scan". Even if I could get past this, consider the following:


> x <- '\t'
> gsub('\\', '/', x, fixed=TRUE)
[1] "\t"


It seems far from trivial, which is why I wrote this function and am looking for a better one.


      Thanks for the reply.


      Spencer

The rest of this e-mail makes absolutely no sense to me -- what exactly are you 
taking about? What else do you want to achieve?

Cheers,
Simon






      Several years ago, Prof. Ripley provided a solution, which I lost and 
have not been able to find.


      Below please find a function to do this.  I do not find this very satisfactory, however, because it uses 
"scan" and therefore operates on an input not a character string.  Unless someone suggests something better, 
I plan to add this to the "sos" package and issue a new release very soon.  (The new release is needed, 
because the RSiteSearch capability has been modified in a way that breaks the current "findFn" core of 
"sos".)


      Thanks,
      Spencer

back2forwardslash<- function (nmax = 1, pattern = "\\", replacement = "/") {
    x<- scan(what = character(), quote = pattern, nmax = nmax)
    x.<- gsub(pattern, replacement, x, fixed = TRUE)
    paste(x., collapse = " ")
}

(x<- back2forwardslash())
c:\Users\

# nmax must be one more than the number of embedded blanks
(x3<- back2forwardslash(3))
c:\u\a b\c d


--
Spencer Graves, PE, PhD
President and Chief Technology Officer
Structure Inspection and Monitoring, Inc.
751 Emerson Ct.
San José, CA 95126
ph:  408-655-4567
web:  www.structuremonitoring.com

______________________________________________
R-devel@r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-devel


______________________________________________
R-devel@r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-devel



--
Spencer Graves, PE, PhD
President and Chief Technology Officer
Structure Inspection and Monitoring, Inc.
751 Emerson Ct.
San José, CA 95126
ph:  408-655-4567
web:  www.structuremonitoring.com

______________________________________________
R-devel@r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-devel

Reply via email to