diff --git a/NAMESPACE b/NAMESPACE
index d75f824..c1a7cea 100644
--- a/NAMESPACE
+++ b/NAMESPACE
@@ -1 +1,2 @@
 exportPattern("^[[:alpha:]]+")
+importFrom("stats", "quantile")
diff --git a/R/meanimpute.R b/R/meanimpute.R
index cc7cf5e..2fc9634 100644
--- a/R/meanimpute.R
+++ b/R/meanimpute.R
@@ -1,6 +1,5 @@
 #' Meanimputation
+#' @param x A vector
 #' @export
 meanimpute <- function(x) {
-  x[is.na(x)] <- mean(x, na.rm = TRUE)
-  x
-}
+  x[is.na(x)] <- mean(x, na.rm = TRUE)
\ No newline at end of file
diff --git a/R/transformlog.R b/R/transformlog.R
new file mode 100644
index 0000000..f0018ac
--- /dev/null
+++ b/R/transformlog.R
@@ -0,0 +1,8 @@
+transform_log<- function(x){
+  if (x<0) stop("Negative input not allowed")
+  if (x==0) stop("Input 0 not allowed")
+  if (!is.numeric(x)) stop("Not numeric input not allowed")
+  if (is.null(x)) stop("NULL input not allowed")
+  
+  log(x)
+}
diff --git a/R/windsorize.R b/R/windsorize.R
index b4e15e6..b961541 100644
--- a/R/windsorize.R
+++ b/R/windsorize.R
@@ -1,10 +1,20 @@
 #' Windsorize
 #'
 #' Do some windsorization.
+#' @param x A numerical vector.
+#' @param p Quantile value for outliers removal
+#' @examples  
+#' windsorize(c(5,10,15,50))
 #' @export
 windsorize <- function(x, p = .90) {
-  q <- quantile(x, p)
-  x[x >= q] <- q
+  if (length(x) == 0)
+    { stop("Not allowed the use of an empty vector!")}
+  if (all(is.na(x))) 
+    { stop("Not allowed the use of a vector containing only NA!")}
+
+  q <- quantile(x, probs=c(1-p,p) , na.rm = TRUE)
+  x[x >= q[2] ] <- q[2]
+  x[x <= q[1] ] <- q[1]
   x
 }