--- a/scripts/general/gradient.m
+++ b/scripts/general/gradient.m
@@ -88,7 +88,7 @@
   if (isvector (m))
     ## make a row vector.
     transposed = (size (m, 2) == 1);
-    m = m(:)';
+    m = m(:).';
   endif
 
   nd = ndims (m);
@@ -259,6 +259,34 @@
 %! assert (all(dU(:)==2));
 
 %!test
+%! [Y,X,Z,U] = ndgrid (2:2:8,1:5,4:4:12,3:5:30);
+%! [dX,dY,dZ,dU] = gradient (X+j*X);
+%! assert (all(dX(:)==1+1j));
+%! assert (all(dY(:)==0));
+%! assert (all(dZ(:)==0));
+%! assert (all(dU(:)==0));
+%! [dX,dY,dZ,dU] = gradient (Y-j*Y);
+%! assert (all(dX(:)==0));
+%! assert (all(dY(:)==2-j*2));
+%! assert (all(dZ(:)==0));
+%! assert (all(dU(:)==0));
+%! [dX,dY,dZ,dU] = gradient (Z+j*1);
+%! assert (all(dX(:)==0));
+%! assert (all(dY(:)==0));
+%! assert (all(dZ(:)==4));
+%! assert (all(dU(:)==0));
+%! [dX,dY,dZ,dU] = gradient (U-j*1);
+%! assert (all(dX(:)==0));
+%! assert (all(dY(:)==0));
+%! assert (all(dZ(:)==0));
+%! assert (all(dU(:)==5));
+%! assert (size_equal(dX, dY, dZ, dU, X, Y, Z, U));
+%! [dX,dY,dZ,dU] = gradient (U, 5.0);
+%! assert (all(dU(:)==1));
+%! [dX,dY,dZ,dU] = gradient (U, 1.0, 2.0, 3.0, 2.5);
+%! assert (all(dU(:)==2));
+
+%!test
 %! x = 0:10;
 %! f = @cos;
 %! df_dx = @(x) -sin (x);