milton ruser wrote:
> Hi Maura,
>
> It is not "elegant" but may work.
>
>
> actual.string<- "12345abcdefgh12345abcdefgh"
> actual.string
> actual.string<-paste(substr(actual.string,
> nchar(actual.string),nchar(actual.string)),
> substr(actual.string, 1,nchar(actual.string)-1), sep="")
> actual.string
>
>
> #in a looping
>
> actual.string<- "12345abcdefgh12345abcdefgh"
> number.buffers<-10
> my.buffers<-actual.string
> for (i in 1:number.buffers)
> {
> actual.string<-paste(substr(actual.string,
> nchar(actual.string),nchar(actual.string)),
> substr(actual.string, 1,nchar(actual.string)-1), sep="")
> my.buffers<-c(my.buffers, actual.string)
> }
> my.buffers
>
>
not sure if this is what you want, but it might provide a hint:
circularize = function(string) {
name = deparse(substitute(string))
index = 0
length = nchar(string)
rm(list=name, envir=parent.frame())
makeActiveBinding(
name,
function(value, ...)
if (missing(value)) {
index <<- index %% length + 1
if (index == 1) string
else paste(
substr(string, index, length),
substr(string, 1, index-1),
sep='') }
else
stop(sprintf('cannot assign to circularized string
"%s"', name)),
parent.frame()) }
string = 'foo'
circularize(string)
string
# "foo"
string
# "oof"
string
# "ofo"
string
# "foo"
# ...
> Ciao,
>
> milton
> brazil=toronto
> On Sun, May 24, 2009 at 1:09 PM, <mau...@alice.it> wrote:
>
>
>> Some wavelet analysis experts have implemented periodic boundary conditions
>> for signals.
>> I need to implement a circular buffer. Something like:
>> "12345abcdefgh12345abcdefgh"
>> so that at each step the riightmost element is moved to the leftmost index
>> and everything else is properly shifted:
>> "h12345abcdefgh12345abcdefg", "gh12345abcdefgh12345abcdef", ....
>>
>> My implementation (still debugging) seems to start working but is terribly
>> clumsy.
>> I am sure that some expert can suggest a more elegant solution,
>> Thank you.
>> Maura
>>
>>
>>
>> tutti i telefonini TIM!
>>
>>
>> [[alternative HTML version deleted]]
>>
>> ______________________________________________
>> R-help@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<http://www.r-project.org/posting-guide.html>
>> and provide commented, minimal, self-contained, reproducible code.
>>
>>
>
> [[alternative HTML version deleted]]
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