Having trouble understanding this syntax for R

Question

I have been given following code for R, but I am having trouble understanding what it is doing. In fact I can not even run it in R because of its syntax. I assume the syntax is for lower level code behind R. If someone could help explain what's happening here and translate this into executable R code that would be very helpful.

soft_thresholding = function(x,a){
  result  a)]  a)] - a
  result[which(x < -a)] = x[which(x < -a)] + a
  return(result)}

Answer 1

Here is a summary of the findings. This is not a definite answer but could help the questioner.

1. If one uses wordpress, then x <- a will look like x < -a. Check this URL that confirms this assumption
2. Upon further online search with the function name in the question "soft_thresholding", shows that this function is probably attempting to do soft thresholding defined here .
3. Some more online searching about soft thresholding lands on a CRAN package that is present here .
4. Further deepdive into the r folder in the package binaries shows the following.

soft.threshold <- function(x,sumabs=1) 
return(soft(x, BinarySearch(x,sumabs)))

5. The function above seems very close to the code in the question.
6. Furthermore, the soft.threshold function uses another internal function BinarySearch that looks like this.

BinarySearch <-
function(argu,sumabs){
  if(norm2(argu)==0 || sum(abs(argu/norm2(argu)))<=sumabs) return(0)
  lam_max = max(abs(argu))
  lam1      <- 0
  lam2      <- lam_max
  iter <- 1
  while(iter < 500){
    su <- soft(argu,(lam1+lam2)/2)
    if(sum(abs(su/norm2(su)))<sumabs){
      lam2 <- (lam1+lam2)/2
    } else {
      lam1 <- (lam1+lam2)/2
    }
    if((lam2-lam1)/lam1 < 1e-10){
      if (lam2 != lam_max){
        return(lam2)
      }else{
        return(lam1)
      }
    }
    iter <- iter+1
  }
  warning("Didn't quite converge")
  return((lam1+lam2)/2)
}

7. This recursive research leads one to believe that the function is perhaps attempting to mimic the function soft.threshold in the CRAN package "RGCCA"

Hope it helps