diff --git a/R/Clim.R b/R/Clim.R
index caf96cae912d803d65cc70d173a5283e855fc71a..0de6f828e7a921ccd70ae851cf74215181653bcc 100644
--- a/R/Clim.R
+++ b/R/Clim.R
@@ -177,8 +177,8 @@ Clim <- function(exp, obs, time_dim = 'sdate', dat_dim = c('dataset', 'member'),
     outrows_obs <- outrows_exp
 
     for (i in 1:length(pos)) {
-      outrows_exp <- InsertDim(outrows_exp, pos[i], dim(exp)[pos[i]], ncores = ncores)
-      outrows_obs <- InsertDim(outrows_obs, pos[i], dim(obs)[pos[i]], ncores = ncores)
+      outrows_exp <- InsertDim(outrows_exp, pos[i], dim(exp)[pos[i]])
+      outrows_obs <- InsertDim(outrows_obs, pos[i], dim(obs)[pos[i]])
     }
     exp[which(is.na(outrows_exp))] <- NA
     obs[which(is.na(outrows_obs))] <- NA
@@ -331,9 +331,9 @@ Clim <- function(exp, obs, time_dim = 'sdate', dat_dim = c('dataset', 'member'),
 
     # Create initial data set (i.e., only first ftime)
     tmp <- Subset(exp, ftime_dim, 1, drop = 'selected')
-    ini_exp <- InsertDim(tmp, pos_ftime, dim_ftime, ncores = ncores_input) #only first ftime
+    ini_exp <- InsertDim(tmp, pos_ftime, dim_ftime) #only first ftime
     tmp <- Subset(obs, ftime_dim, 1, drop = 'selected')
-    ini_obs <- InsertDim(tmp, pos_ftime, dim_ftime, ncores = ncores_input) #only first ftime
+    ini_obs <- InsertDim(tmp, pos_ftime, dim_ftime) #only first ftime
     #ini_: [sdate, dat_dim, ftime]
     tmp_exp <- Regression(datay = exp, datax = ini_exp, reg_dim = time_dim,
                           na.action = na.omit,
diff --git a/R/Corr.R b/R/Corr.R
index 14f5c581edd2e4a1d676b79fa57c47f46175e9bd..463d5f84e22f9646d04ed089b251aba9f81a4a06 100644
--- a/R/Corr.R
+++ b/R/Corr.R
@@ -228,7 +228,7 @@ Corr <- function(exp, obs, time_dim = 'sdate', dat_dim = 'dataset',
     pos <- which(names(dim(obs)) == comp_dim)
     obs_sub <- Subset(obs, pos, list(limits[1]:limits[2]))
     outrows <- is.na(MeanDims(obs_sub, pos, na.rm = FALSE, ncores = ncores))
-    outrows <- InsertDim(outrows, pos, dim(obs)[comp_dim], ncores = ncores)
+    outrows <- InsertDim(outrows, pos, dim(obs)[comp_dim])
     obs[which(outrows)] <- NA
   }
 
diff --git a/R/InsertDim.R b/R/InsertDim.R
index e2daccbf9cd59727ed874a4e47feca8adeb4c148..950479c44297ce0eb8c96392e5961792da70bfe6 100644
--- a/R/InsertDim.R
+++ b/R/InsertDim.R
@@ -8,8 +8,6 @@
 #'@param lendim An integer indicating the length of the new dimension.
 #'@param name A character string indicating the name for the new dimension. 
 #'  The default value is NULL.
-#'@param ncores An integer indicating the number of cores to use for parallel 
-#'  computation. The default value is NULL.
 #'
 #'@return An array as parameter 'data' but with the added named dimension.
 #'
@@ -20,7 +18,7 @@
 #'
 #'@import multiApply
 #'@export
-InsertDim <- function(data, posdim, lendim, name = NULL, ncores = NULL) {
+InsertDim <- function(data, posdim, lendim, name = NULL) {
 
   # Check inputs 
   ## data
@@ -61,54 +59,24 @@ InsertDim <- function(data, posdim, lendim, name = NULL, ncores = NULL) {
       stop("Parameter 'name' must be a character string.")
     }
   }
-  # ncores
-  if (!is.null(ncores)) {
-    if (!is.numeric(ncores) | ncores %% 1 != 0 | ncores <= 0 |
-      length(ncores) > 1) {
-      stop("Parameter 'ncores' must be a positive integer.")
-    }
-  }
 
   ###############################
   # Calculate InsertDim
+  names(lendim) <- name
 
-  ## create output dimension
-  if (posdim == 1) { # first dim
-    outdim <- c(lendim, dim(data))
-  } else {
-    if (posdim > length(dim(data))) { # last dim
-      outdim <- c(dim(data), lendim)
-    } else { # middle dim
-    outdim <- c(dim(data)[1:(posdim - 1)], lendim, dim(data)[posdim:length(dim(data))])
-    }
-  }
-
-  ## create output array
-  outvar <- array(dim = c(outdim))
-  ## give temporary names for Apply(). The name will be replaced by data in the end
-  names(dim(outvar)) <- paste0('D', 1:length(outdim))
-  names(dim(outvar))[posdim] <- name
+  ## Put the new dim at the end first
+  data <- array(data, dim = c(dim(data), lendim))
 
-  res <- Apply(list(outvar), 
-               margins = name, 
-               fun = .InsertDim, 
-               val = data,
-               ncores = ncores)$output1
-
-  if (posdim != 1) {
-    if (posdim < length(outdim)) {
-    res <- Reorder(res, c(1:(posdim - 1), length(outdim), posdim:(length(outdim) - 1)))
-    } else {  #posdim = length(outdim)
-        res <- Reorder(res, c(1:(posdim - 1), length(outdim)))
-    }
-  } else {
-      res <- Reorder(res, c(length(outdim), 1:(length(outdim) - 1)))
+  ## Reorder dimension
+  if (posdim == 1) {
+    order <- c(length(dim(data)), 1:(length(dim(data)) - 1))
+    data <- Reorder(data, order)
+  } else if (posdim == length(dim(data))) {  # last dim
+  
+  } else { # middle dim
+    order <- c(1:(posdim - 1), length(dim(data)), posdim:(length(dim(data)) - 1))
+    data <- Reorder(data, order)
   }
 
-  return(res)
-}
-
-.InsertDim <- function(x, val) {
-  x <- val
-  return(x)
+  return(data)
 }
diff --git a/R/RMS.R b/R/RMS.R
index 86d44619ff53302bfd5adfc4af38deb5dc7de4c0..b3c8ad4b016d18cc9f3dfd79ddaeb3bb38ba15b0 100644
--- a/R/RMS.R
+++ b/R/RMS.R
@@ -181,7 +181,7 @@ RMS <- function(exp, obs, time_dim = 'sdate', dat_dim = 'dataset',
     pos <- which(names(dim(obs)) == comp_dim)
     obs_sub <- Subset(obs, pos, list(limits[1]:limits[2]))
     outrows <- is.na(MeanDims(obs_sub, pos, na.rm = FALSE))
-    outrows <- InsertDim(outrows, pos, dim(obs)[comp_dim], ncores = ncores)
+    outrows <- InsertDim(outrows, pos, dim(obs)[comp_dim])
     obs[which(outrows)] <- NA
   }
   
diff --git a/R/Season.R b/R/Season.R
index a1402afc5e952c38f9231c363ac94418a1c492be..d56aa1637fd77204db76061492a7d14fea9e8a87 100644
--- a/R/Season.R
+++ b/R/Season.R
@@ -137,7 +137,7 @@ Season <- function(data, time_dim = 'ftime', monini, moninf, monsup,
                      monini = monini, moninf = moninf, monsup = monsup,
                      method = method, na.rm = na.rm)
         if (length(dim(res)) < length(dim(data))) {
-          res <- InsertDim(res, posdim = 1, lendim = 1, name = time_dim, ncores = ncores)
+          res <- InsertDim(res, posdim = 1, lendim = 1, name = time_dim)
         } else {
           names(dim(res))[1] <- time_dim
         }
diff --git a/man/ACC.Rd b/man/ACC.Rd
index d48d6b8fa01aca912ecd6ca5dfac319d0402a2f5..d1389fdb596ee9a2162723d8c1ce1410f3542b19 100644
--- a/man/ACC.Rd
+++ b/man/ACC.Rd
@@ -4,10 +4,22 @@
 \alias{ACC}
 \title{Compute the anomaly correlation coefficient between the forecast and corresponding observation}
 \usage{
-ACC(exp, obs, dat_dim = "dataset", space_dim = c("lat", "lon"),
-  avg_dim = "sdate", memb_dim = "member", lat = NULL, lon = NULL,
-  lonlatbox = NULL, conf = TRUE, conftype = "parametric",
-  conf.lev = 0.95, pval = TRUE, ncores = NULL)
+ACC(
+  exp,
+  obs,
+  dat_dim = "dataset",
+  space_dim = c("lat", "lon"),
+  avg_dim = "sdate",
+  memb_dim = "member",
+  lat = NULL,
+  lon = NULL,
+  lonlatbox = NULL,
+  conf = TRUE,
+  conftype = "parametric",
+  conf.lev = 0.95,
+  pval = TRUE,
+  ncores = NULL
+)
 }
 \arguments{
 \item{exp}{A numeric array of experimental anomalies with named dimensions.
@@ -141,4 +153,3 @@ PlotACC(res_bootstrap, startDates)
 Joliffe and Stephenson (2012). Forecast Verification: A 
  Practitioner's Guide in Atmospheric Science. Wiley-Blackwell.
 }
-
diff --git a/man/InsertDim.Rd b/man/InsertDim.Rd
index c0dd7d861f1cdd18a025dc01daf3c06b52014f20..7a866a37c2887855ea5d5885f2d23a6569c8fbf2 100644
--- a/man/InsertDim.Rd
+++ b/man/InsertDim.Rd
@@ -4,7 +4,7 @@
 \alias{InsertDim}
 \title{Add a named dimension to an array}
 \usage{
-InsertDim(data, posdim, lendim, name = NULL, ncores = NULL)
+InsertDim(data, posdim, lendim, name = NULL)
 }
 \arguments{
 \item{data}{An array to which the additional dimension to be added.}
@@ -15,9 +15,6 @@ InsertDim(data, posdim, lendim, name = NULL, ncores = NULL)
 
 \item{name}{A character string indicating the name for the new dimension. 
 The default value is NULL.}
-
-\item{ncores}{An integer indicating the number of cores to use for parallel 
-computation. The default value is NULL.}
 }
 \value{
 An array as parameter 'data' but with the added named dimension.
diff --git a/man/PlotACC.Rd b/man/PlotACC.Rd
index 1dbd7cf6579e33460c0c79f83ad5731914ebd8cb..cd2b35729db4cdb4d2cabb7005ea7340b6f783a3 100644
--- a/man/PlotACC.Rd
+++ b/man/PlotACC.Rd
@@ -4,11 +4,27 @@
 \alias{PlotACC}
 \title{Plot Plumes/Timeseries Of Anomaly Correlation Coefficients}
 \usage{
-PlotACC(ACC, sdates, toptitle = "", sizetit = 1, ytitle = "",
-  limits = NULL, legends = NULL, freq = 12, biglab = FALSE,
-  fill = FALSE, linezero = FALSE, points = TRUE, vlines = NULL,
-  fileout = NULL, width = 8, height = 5, size_units = "in", res = 100,
-  ...)
+PlotACC(
+  ACC,
+  sdates,
+  toptitle = "",
+  sizetit = 1,
+  ytitle = "",
+  limits = NULL,
+  legends = NULL,
+  freq = 12,
+  biglab = FALSE,
+  fill = FALSE,
+  linezero = FALSE,
+  points = TRUE,
+  vlines = NULL,
+  fileout = NULL,
+  width = 8,
+  height = 5,
+  size_units = "in",
+  res = 100,
+  ...
+)
 }
 \arguments{
 \item{ACC}{An ACC array with with dimensions:\cr
@@ -106,4 +122,3 @@ PlotACC(res, startDates)
 PlotACC(res_bootstrap, startDates)
  }
 }
-
diff --git a/tests/testthat/test-InsertDim.R b/tests/testthat/test-InsertDim.R
index c4d3226ff66a795cf937fb21431f5158e6835028..f3cfab801f33fd29e44e805ae65d6f8c52d9dad7 100644
--- a/tests/testthat/test-InsertDim.R
+++ b/tests/testthat/test-InsertDim.R
@@ -42,14 +42,14 @@ test_that("1. Input checks", {
   InsertDim(1:10, posdim = 1, lendim = 1, name = 1),
   "Parameter 'name' must be a character string."
   )
-  expect_error(
-  InsertDim(1:10, posdim = 1, lendim = 1, ncores = 'a'),
-  "Parameter 'ncores' must be a positive integer."
-  )
-  expect_error(
-  InsertDim(1:10, posdim = 1, lendim = 1, ncores = 0),
-  "Parameter 'ncores' must be a positive integer."
-  )
+#  expect_error(
+#  InsertDim(1:10, posdim = 1, lendim = 1, ncores = 'a'),
+#  "Parameter 'ncores' must be a positive integer."
+#  )
+#  expect_error(
+#  InsertDim(1:10, posdim = 1, lendim = 1, ncores = 0),
+#  "Parameter 'ncores' must be a positive integer."
+#  )
 
 })