diff --git a/R/RMSSS.R b/R/RMSSS.R
index 4f115d3cdb68433e53dcc3a903bbea6e1c1de02d..5967bd00ebcead4a20a80382b445187484058a28 100644
--- a/R/RMSSS.R
+++ b/R/RMSSS.R
@@ -13,11 +13,15 @@
 #'The p-value is optionally provided by an one-sided Fisher test.\cr
 #'
 #'@param exp A named numeric array of experimental data which contains at least
-#'  two dimensions for memb_dim and time_dim.
+#'  two dimensions for memb_dim and time_dim. It can also be a vector with the 
+#'  same length as 'obs', then the vector will automatically be 'time_dim' and 
+#'  'memb_dim' will be 1.
 #'@param obs A named numeric array of observational data which contains at least
 #'  two dimensions for memb_dim and time_dim. The dimensions should be the same 
 #'  as paramter 'exp' except the length of 'memb_dim' dimension. The order of 
-#'  dimension can be different.
+#'  dimension can be different. It can also be a vector with the same length as
+#'  'exp', then the vector will automatically be 'time_dim' and 'memb_dim' will
+#'  be 1.
 #'@param memb_dim A character string indicating the name of member (nobs/nexp) 
 #'  dimension. The default value is 'member'.
 #'@param time_dim A character string indicating the name of dimension along  
@@ -62,9 +66,19 @@ RMSSS <- function(exp, obs, time_dim = 'sdate', memb_dim = 'member',
   if (!is.numeric(exp) | !is.numeric(obs)) {
     stop("Parameter 'exp' and 'obs' must be a numeric array.")
   }
-  if (is.null(dim(exp)) | is.null(dim(obs))) {
-    stop(paste0("Parameter 'exp' and 'obs' must be at least two dimensions ",
-                "containing time_dim and memb_dim."))
+  if (is.null(dim(exp)) & is.null(dim(obs))) {  #is vector
+    if (length(exp) == length(obs)) {
+      exp <- array(exp, dim = c(length(exp), 1))
+      names(dim(exp)) <- c(time_dim, memb_dim)
+      obs <- array(obs, dim = c(length(obs), 1))
+      names(dim(obs)) <- c(time_dim, memb_dim)
+    } else {
+    stop(paste0("Parameter 'exp' and 'obs' must be array with as least two ",
+                "dimensions time_dim and memb_dim, or vector of same length."))
+    }
+  } else if (is.null(dim(exp)) | is.null(dim(obs))) {
+    stop(paste0("Parameter 'exp' and 'obs' must be array with as least two ",
+                "dimensions time_dim and memb_dim, or vector of same length."))
   }
   if(any(is.null(names(dim(exp))))| any(nchar(names(dim(exp))) == 0) |
      any(is.null(names(dim(obs))))| any(nchar(names(dim(obs))) == 0)) {
diff --git a/man/RMSSS.Rd b/man/RMSSS.Rd
index 3b9c1be48f6aee17c4ce51c11a01f8dca28f3559..0939a94730c08ec0e297064dcdccdd9f61d85297 100644
--- a/man/RMSSS.Rd
+++ b/man/RMSSS.Rd
@@ -9,12 +9,16 @@ RMSSS(exp, obs, time_dim = "sdate", memb_dim = "member", pval = TRUE,
 }
 \arguments{
 \item{exp}{A named numeric array of experimental data which contains at least
-two dimensions for memb_dim and time_dim.}
+two dimensions for memb_dim and time_dim. It can also be a vector with the 
+same length as 'obs', then the vector will automatically be 'time_dim' and 
+'memb_dim' will be 1.}
 
 \item{obs}{A named numeric array of observational data which contains at least
 two dimensions for memb_dim and time_dim. The dimensions should be the same 
 as paramter 'exp' except the length of 'memb_dim' dimension. The order of 
-dimension can be different.}
+dimension can be different. It can also be a vector with the same length as
+'exp', then the vector will automatically be 'time_dim' and 'memb_dim' will
+be 1.}
 
 \item{time_dim}{A character string indicating the name of dimension along
 which the RMSSS are computed. The default value is 'sdate'.}
diff --git a/tests/testthat/test-RMSSS.R b/tests/testthat/test-RMSSS.R
index 9242d6dd8b1a94332f258c3f2df5f9352a56e565..7d5cc8d4223b2b0f1007e16d62a35ce561e91602 100644
--- a/tests/testthat/test-RMSSS.R
+++ b/tests/testthat/test-RMSSS.R
@@ -19,6 +19,12 @@ context("s2dv::RMSSS tests")
  set.seed(4)
  obs2 <- array(rnorm(60), dim = c(dat = 1, sdate = 10, member = 1, lat = 2, lon = 3))
 
+ # case 3: vector
+ set.seed(5)
+ exp3 <- rnorm(10)
+ set.seed(6)
+ obs3 <- rnorm(10)
+
 ##############################################
 
 test_that("1. Input checks", {
@@ -33,11 +39,11 @@ test_that("1. Input checks", {
   )
   expect_error(
   RMSSS(c(1:10), c(2:4)),
-  paste0("Parameter 'exp' and 'obs' must be at least two dimensions ",
-                "containing time_dim and memb_dim.")
+  paste0("Parameter 'exp' and 'obs' must be array with as least two dimensions ",
+         "time_dim and memb_dim, or vector of same length.")
   )
   expect_error(
-  RMSSS(array(1:10, dim = c(2, 5)), array(1:4, dim = c(2, 2))),
+  RMSSS(array(1:10, dim = c(2, 5)), array(1:10, dim = c(2, 5))),
   "Parameter 'exp' and 'obs' must have dimension names."
   )
   expect_error(
@@ -81,7 +87,7 @@ test_that("1. Input checks", {
 })
 
 ##############################################
-test_that("1. Output checks: case 1", {
+test_that("2. Output checks: case 1", {
 
   res1_1 <- RMSSS(exp1, obs1, time_dim = 'time', memb_dim = 'memb')
   expect_equal(
@@ -118,7 +124,7 @@ test_that("1. Output checks: case 1", {
 
 
 ##############################################
-test_that("2. Output checks: case 2", {
+test_that("3. Output checks: case 2", {
 
   expect_equal(
     dim(RMSSS(exp2, obs2)$rmsss),
@@ -139,4 +145,17 @@ test_that("2. Output checks: case 2", {
 
 ##############################################
 
+test_that("4. Output checks: case 3", {
+
+  expect_equal(
+    dim(RMSSS(exp3, obs3)$rmsss),
+    c(nexp = 1, nobs = 1)
+  )
+  expect_equal(
+  as.vector(RMSSS(exp3, obs3)$rmsss),
+  -0.6289915,
+  tolerance = 0.00001
+  )
+
 
+})