diff --git a/CHANGELOG b/CHANGELOG
index c55a998..8715cf4 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -1,3 +1,8 @@
+2.1.0 - Thomas J. Leeper
+
+- Added `unf.array()` method. (#18)
+- Added `sort` argument to `unf()` to optionally not sort column UNF hashes. (#18)
+
 2.0.5 - Thomas J. Leeper
 
 - Exported new function `unf_equal()` to better comply with R CMD check.
diff --git a/DESCRIPTION b/DESCRIPTION
index 6de4d3b..c95254e 100644
--- a/DESCRIPTION
+++ b/DESCRIPTION
@@ -1,7 +1,7 @@
 Package: UNF
-Version: 2.0.6
+Version: 2.1.0
 Title: Tools for Creating Universal Numeric Fingerprints for Data
-Date: 2016-08-09
+Date: 2017-05-08
 Authors@R: c(person("Thomas", "Leeper", role = c("aut","cre"),
                     email = "thosjleeper@gmail.com"),
              person("Micah", "Altman", role = c("aut")))
@@ -23,4 +23,4 @@ License: GPL-2
 URL: https://github.com/leeper/UNF
 BugReports: https://github.com/leeper/UNF/issues
 VignetteBuilder: knitr
-RoxygenNote: 5.0.1
+RoxygenNote: 6.0.1
diff --git a/NAMESPACE b/NAMESPACE
index d142bff..af0f27f 100644
--- a/NAMESPACE
+++ b/NAMESPACE
@@ -17,6 +17,7 @@ S3method(as.unfvector,ts)
 S3method(print,UNF)
 S3method(print,UNFtest)
 S3method(print,unfvector)
+S3method(unf,array)
 S3method(unf,data.frame)
 S3method(unf,default)
 S3method(unf,list)
diff --git a/R/unf.R b/R/unf.R
index c0f17cb..4c4e206 100644
--- a/R/unf.R
+++ b/R/unf.R
@@ -2,6 +2,7 @@
 #' @description UNF is a cryptographic hash or signature that can be used to uniquely identify (a version of) a dataset, or a subset thereof.
 #' @param x For \code{unf}, a vector, matrix, dataframe, or list; for \code{unf3}, \code{unf4}, \code{unf5}, a vector. If \code{x} is a dataframe or list with one variable or one vector element, respectively, \code{unf} returns the UNF for the single vector (which is consistent with the Dataverse implementation but ambiguous in the UNF standard). For algorithm versions < 5, all non-numeric vectors are treated as character.
 #' @param version Version of the UNF algorithm. Allowed values are 3, 4, 4.1, 5, and 6. Always use the same version of the algorithm to check a UNF. Default for \code{unf} is 6 and default for \code{unf4} is 4 (but can also be set to 4.1, which is identical except for using SHA256 instead of MD5).
+#' @param sort A logical indicating whether to sort the columns/variables of a matrix or data frame. The default is \code{TRUE}. If \code{FALSE}, column order is respected when calculating the final UNF hash. This can be useful for distinguishing two matrices from one another.
 #' @param digits The number of significant digits for rounding for numeric values. Default is 7L. Must be between 1 and 15.
 #' @param characters The number of characters for truncation. Default is 128L. Must be greater than 1.
 #' @param truncation The number of bits to truncate the UNF signature to. Default is 128L. Must be one of: 128,192,196,256.
@@ -125,32 +126,38 @@ unf.default <- function(x, version = 6, ...) {
 }
 
 #' @export
-unf.data.frame <- function(x, version = 6, ...){
+unf.data.frame <- function(x, version = 6, sort = TRUE, ...){
     if (length(x) == 1) {
         return(unf(x[[1]], version = version, ...))
     }
-    locale <- Sys.getlocale(category="LC_COLLATE")
-    Sys.setlocale(category="LC_COLLATE", "C")
-    on.exit(Sys.setlocale(category="LC_COLLATE", locale))
+    if (isTRUE(sort)) {
+        sort_fun <- sort
+        locale <- Sys.getlocale(category="LC_COLLATE")
+        Sys.setlocale(category="LC_COLLATE", "C")
+        on.exit(Sys.setlocale(category="LC_COLLATE", locale))
+    } else {
+        sort_fun <- function(x) x
+    }
     if (version == 3) {
         vars <- sapply(x, function(i) unf3(i, ...)$unf)
-        out <- unf3(sort(vars), ...)
+        out <- unf3(sort_fun(vars), ...)
     } else if (version == 4) {
         vars <- sapply(x, function(i) unf4(i, ...)$unf)
-        out <- unf4(sort(vars), ...)
+        out <- unf4(sort_fun(vars), ...)
     } else if (version == 4.1) {
         vars <- sapply(x, function(i) unf4(i, version = 4.1, ...)$unf)
-        out <- unf4(sort(vars), version = 4.1, ...)
+        out <- unf4(sort_fun(vars), version = 4.1, ...)
     } else if (version == 5) {
         vars <- sapply(x, function(i) unf5(i, ...)$unf)
-        out <- unf5(sort(vars), ...)
+        out <- unf5(sort_fun(vars), ...)
     } else if (version == 6) {
         vars <- sapply(x, function(i) unf6(i, ...)$unf)
-        out <- unf6(sort(vars), ...)
+        out <- unf6(sort_fun(vars), ...)
     } else {
         stop("Unrecognized UNF version: must be 3, 4, 4.1, 5, or 6.")
     }
     out$variables <- vars
+    attr(out, "sort") <- sort
     return(out)
 }
 
@@ -160,8 +167,13 @@ unf.list <- function(x, version = 6, ...) {
 }
 
 #' @export
-unf.matrix <- function(x, version = 6, ...) {
-    unf(as.data.frame(x), version = version, ...)
+unf.matrix <- function(x, version = 6, sort = TRUE, ...) {
+    unf(as.data.frame(x), version = version, sort = sort, ...)
+}
+
+#' @export
+unf.array <- function(x, version = 6, sort = TRUE, ...) {
+    unf(as.data.frame(x), version = version, sort = sort, ...)
 }
 
 #' @export
diff --git a/man/UNF-package.Rd b/man/UNF-package.Rd
index 8935218..f745e6c 100644
--- a/man/UNF-package.Rd
+++ b/man/UNF-package.Rd
@@ -2,8 +2,8 @@
 % Please edit documentation in R/UNF-package.R
 \docType{package}
 \name{UNF-package}
-\alias{UNF}
 \alias{UNF-package}
+\alias{UNF}
 \title{Tools for creating universal numeric fingerprints for data}
 \description{
 Computes a univeral numeric fingerprint of data objects.
@@ -21,11 +21,10 @@ A UNF differs from an ordinary file checksum in several important ways:
   \item \emph{UNFs are strongly tamper resistant.} Any accidental or intentional changes to data values will change the resulting UNF. Most file checksums and descriptive statistics detect only certain types of changes.
 }
 }
-\author{
-Thomas J. Leeper and Micah Altman.
-}
 \seealso{
 \code{\link{unf}} \code{\link{\%unf\%}}
 }
+\author{
+Thomas J. Leeper and Micah Altman.
+}
 \keyword{package}
-
diff --git a/man/as.unfvector.Rd b/man/as.unfvector.Rd
index 9e09cf3..20278bb 100644
--- a/man/as.unfvector.Rd
+++ b/man/as.unfvector.Rd
@@ -20,10 +20,9 @@ Standardize a vector according to UNF specifications
 \details{
 The UNF specifications describes how to coerce all R data types to a standardized character representation. This S3 method exposes that coercion functionality.
 }
-\author{
-Thomas J. Leeper (\email{thosjleeper@gmail.com})
-}
 \seealso{
 \code{\link{unf}}, \code{\link{unf6}}, \code{\link{\%unf\%}}
 }
-
+\author{
+Thomas J. Leeper (\email{thosjleeper@gmail.com})
+}
diff --git a/man/equal.Rd b/man/equal.Rd
index d7423c4..4ba37ca 100644
--- a/man/equal.Rd
+++ b/man/equal.Rd
@@ -35,11 +35,10 @@ unf_equal(a, b, digits = 3)
 
 unf(a) \%unf\% "UNF6:aKW4lAFNBH8vfrnrDbQZjg=="
 
-}
-\author{
-Thomas J. Leeper
 }
 \seealso{
 \code{\link{unf}}
 }
-
+\author{
+Thomas J. Leeper
+}
diff --git a/man/signifz.Rd b/man/signifz.Rd
index 2a274c4..5ceef76 100644
--- a/man/signifz.Rd
+++ b/man/signifz.Rd
@@ -23,11 +23,10 @@ Rounding toward zero assures that \code{signifz(signifz(x,digits=m),digits=n)} =
 signif(pi,digits=5)
 signifz(pi,digits=5)
 
-}
-\author{
-Micah Altman
 }
 \seealso{
 \code{\link[base]{signif}}, \code{\link{unf}}
 }
-
+\author{
+Micah Altman
+}
diff --git a/man/unf.Rd b/man/unf.Rd
index 7b4129a..58d4c45 100644
--- a/man/unf.Rd
+++ b/man/unf.Rd
@@ -58,6 +58,8 @@ unf6(x, digits = 7L, characters = 128L, truncation = 128L,
 
 \item{complex_as_character}{A logical indicating whether to format raw vectors as character. If \code{TRUE}, UNF should match Dataverse UNFv5 implementation. If \code{FALSE}, complex numbers are formatted as \code{A,iB}.}
 
+\item{sort}{A logical indicating whether to sort the columns/variables of a matrix or data frame. The default is \code{TRUE}. If \code{FALSE}, column order is respected when calculating the final UNF hash. This can be useful for distinguishing two matrices from one another.}
+
 \item{\ldots}{Additional arguments passed to specific algorithm functions. Ignored.}
 }
 \value{
@@ -152,4 +154,3 @@ Data Citation Synthesis Group. 2013. Declaration of Data Citation Principles [DR
 \seealso{
 \code{\link{\%unf\%}}
 }
-