[R] String position character replacement

[Petr Savicky]

On Wed, Feb 08, 2012 at 01:30:55PM -0500, Sarah Goslee wrote:
> And here's an alternative solution:
> 
> subchar <- function(string, pos, char="-") {
> 	for(i in pos) {
>    	string <- gsub(paste("^(.{", i-1, "}).", sep=""), "\\1-", string)
> 	}
> 	string
> }

Hi.

Try the following modification.

  subchar2 <- function(string, pos) {
    for(i in pos) {
        substr(string, i, i) <- "-"
    }
    string
  }

  avec <- c("hellohowareyoudoing", "imgoodhowareyou", "goodandyou", "yesimgoodijusttoldyou", "ohyesthatsright")
  alist <- list(c(3, 9), c(3, 4), c(4, 7), c(5,6,7,8,9), c(2,5,7,12))
  sapply(1:length(avec), function(x) subchar2(avec[x], alist[[x]]))

  [1] "he-lohow-reyoudoing"   "im--odhowareyou"       "goo-an-you"           
  [4] "yesi-----ijusttoldyou" "o-ye-t-atsr-ght"      

Hope this helps.

Petr Savicky.