custom function in R to replace outliers by quartile method -

i have created function in r detect , replace outliers quartile method in r. function working extremely slow large dataset. dataset 1,000,000 rows , 250 columns. numeric.

replaceoutliers3 <- function(x, strength,replacewithna,na.rm = true, ...) {   totalcols<-ncol(x)   totalrows<- nrow(x)    (col in 1:totalcols)   {     cat("starting col ...",col)     cat("\n")     quantiles <- quantile( x[,col], probs=c(.25, .75 ), na.rm= na.rm, ...)     if(strength ==1 )     {       h<-1.5 * iqr(x[,col], na.rm = na.rm)     }     else if(strength ==2)     {       h<-3 * iqr(x[,col], na.rm = na.rm)     }     else     {       stop("please provide correct strength : 1 mild , 2 strong")     }      lowerthresh<-quantiles[1] - h     upperthresh<-quantiles[2] + h      if(replacewithna)     {       (row in 1:totalrows)       {         if(x[row, col] < lowerthresh)         {           x[row, col] <- na         }         if(x[row, col] > upperthresh)         {           x[row, col] <- na         }       }     }     else     {       (row in 1:totalrows)       {         cat("starting row ...",row)         cat("\n")         if(x[row, col] < lowerthresh)         {           x[row, col] <- lowerthresh         }         if(x[row, col] > upperthresh)         {           x[row, col] <- upperthresh         }       }     }     cat("column completed :",col)   }   return(x) } 

i know code crude. can 1 please me code faster version apply , dplyr etc