[R] String manipulation and formatting

[Gabor Grothendieck]

In thinking about this some more it can be substantially simplified.
We don't need f at all -- we can just use repx and we don't need
any backreferences either since we can repeatedly apply the
numeric pattern.  This reduces it to a two line body:

library(gsubfn)
xify <- function(fmt) {
   repx <- function(n) paste(rep("X", n), collapse = "")
   as.vector(gsubfn("[[:digit:]]+", repx, as.character(fmt)))
}

xify(5.2) # XXXXX.XX
xify(5)   # XXXXX


On 7/17/06, Gabor Grothendieck <ggrothendieck at gmail.com> wrote:
> First we define repx(n) to produce n X's.  This
> simple function is used subsequently.  f is a
> function that takes 4 strings which represent the
> entire string and the three backreferenced substrings
> in the subsequent gsub pattern and does the paste.
> x1 will represent the part before the dot and x3 after
> the dot. x2 represents the dot plus x3 and is not used.
> Finally we run gsubfn using the appropriate regex pattern.
>
> library(gsubfn)
> xify <- function(fmt) {
>   repx <- function(n) paste(rep("X", n), collapse = "")
>   f <- function(x, x1= "", x2 = "", x3 = "")
>     if (x3 == "") repx(x1) else paste(repx(x1), ".", repx(x3), sep = "")
>   as.vector(gsubfn("^([[:digit:]]+)(.([[:digit:]])|)", f, as.character(fmt)))
> }
>
> xify(5.2) # XXXXX.XX
> xify(5)   # XXXXX
>
>
> On 7/17/06, Bashir Saghir (Aztek Global) <Saghir.Bashir at ucb-group.com> wrote:
> > I'm trying to write a simple function that does the following:
> >
> >  [command] xify(5.2)
> >  [output] XXX.XX
> >
> >  [command] xify(3)
> >  [output] XXX
> >
> > Any simple solutions (without using python/perl/unix script/...)?
> >
> > Thanks,
> > Saghir
> >
> >
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