--- a/NEWS	Tue Jun 19 09:37:03 2018 -0400
+++ b/NEWS	Tue Jun 19 09:18:44 2018 -0700
@@ -5,6 +5,11 @@
     or "skew" to calculate the symmetric or skew-symmetric property
     of a matrix.  Performance has also been increased.
 
+ ** The issorted function now uses a direction option of "ascend" or
+    "descend" to make it compatible with both the sort function and
+    with Matlab.  Change all uses of "ascending" and "descending" in
+    existing code to the new options.
+
  ** Figure graphic objects have a new property "Number" which is
     read-only and will return the handle (number) of the figure.
     However, if the property "IntegerHandle" has been set to "off" then

--- a/libinterp/corefcn/data.cc	Tue Jun 19 09:37:03 2018 -0400
+++ b/libinterp/corefcn/data.cc	Tue Jun 19 09:18:44 2018 -0700
@@ -6756,14 +6756,14 @@
 
   std::string mode = arg.xstring_value ("issorted: MODE must be a string");
 
-  if (mode == "ascending")
+  if (mode == "ascend")
     smode = ASCENDING;
-  else if (mode == "descending")
+  else if (mode == "descend")
     smode = DESCENDING;
   else if (mode == "either")
     smode = UNSORTED;
   else
-    error (R"(issorted: MODE must be "ascending", "descending", or "either")");
+    error (R"(issorted: MODE must be "ascend", "descend", or "either")");
 
   return smode;
 }
@@ -6847,18 +6847,18 @@
 %!assert (! issorted (uv))
 %!assert (issorted (sv'))
 %!assert (! issorted (uv'))
-%!assert (issorted (sm, "rows", "ascending"))
-%!assert (! issorted (um, "rows", "ascending"))
-%!assert (issorted (sv, "ascending"))
-%!assert (! issorted (uv, "ascending"))
-%!assert (issorted (sv', "ascending"))
-%!assert (! issorted (uv', "ascending"))
-%!assert (! issorted (sm, "rows", "descending"))
-%!assert (issorted (flipud (sm), "rows", "descending"))
-%!assert (! issorted (sv, "descending"))
-%!assert (issorted (fliplr (sv), "descending"))
-%!assert (! issorted (sv', "descending"))
-%!assert (issorted (fliplr (sv)', "descending"))
+%!assert (issorted (sm, "rows", "ascend"))
+%!assert (! issorted (um, "rows", "ascend"))
+%!assert (issorted (sv, "ascend"))
+%!assert (! issorted (uv, "ascend"))
+%!assert (issorted (sv', "ascend"))
+%!assert (! issorted (uv', "ascend"))
+%!assert (! issorted (sm, "rows", "descend"))
+%!assert (issorted (flipud (sm), "rows", "descend"))
+%!assert (! issorted (sv, "descend"))
+%!assert (issorted (fliplr (sv), "descend"))
+%!assert (! issorted (sv', "descend"))
+%!assert (issorted (fliplr (sv)', "descend"))
 %!assert (! issorted (um, "rows", "either"))
 %!assert (! issorted (uv, "either"))
 %!assert (issorted (sm, "rows", "either"))