--- a/scripts/ode/odeget.m	Sun Oct 04 22:18:54 2015 -0700
+++ b/scripts/ode/odeget.m	Mon Oct 05 11:59:18 2015 -0700
@@ -18,79 +18,71 @@
 ## <http://www.gnu.org/licenses/>.
 
 ## -*- texinfo -*-
-## @deftypefn  {Function File} {@var{option} =} odeget (@var{ode_opt}, @var{field})
-## @deftypefnx {Function File} {@var{option} =} odeget (@var{ode_opt}, @var{field}, @var{default})
+## @deftypefn  {Function File} {@var{val} =} odeget (@var{ode_opt}, @var{field})
+## @deftypefnx {Function File} {@var{val} =} odeget (@var{ode_opt}, @var{field}, @var{default})
 ##
 ## Query the value of the property @var{field} in the ODE options structure
 ## @var{ode_opt}.
 ##
-## If this function is called with two input arguments and the first input
-## argument @var{ode_opt} is of type structure array and the second input
-## argument @var{field} is of type string then return the option value
-## @var{res} that is specified by the option name @var{field} in the ODE
-## option structure @var{ode_opt}.
+## If called with two input arguments and the first input argument @var{ode_opt}
+## is a structure and the second input argument @var{field} is a string then
+## return the option value @var{val} that is specified by the option name
+## @var{field} in the ODE option structure @var{ode_opt}.
 ##
-## Optionally if this function is called with a third input argument then
-## return the default value @var{default} if @var{field} is not set in the
-## structure @var{ode_opt}.
+## If called called with an optional third input argument then return the
+## default value @var{default} if @var{field} is not set in the structure
+## @var{ode_opt}.
 ## @seealso{odeset}
 ## @end deftypefn
 
+## FIXME: 4th input argument 'opt' is undocumented.
+
 ## Note: 2006-10-22, Thomas Treichl
 ##   We cannot create a function of the form odeget (@var{odestruct},
 ##   @var{name1}, @var{name2}) because we would get a mismatch with
 ##   the function form 1 like described above.
 
-function res = odeget (ode_opt, field, default, opt)
+function val = odeget (ode_opt, field, default = [], opt)
 
-  ## Check number and types of input arguments
-  if (nargin == 1)
-    error ("OdePkg:InvalidArgument",
-           "input arguments number must be at least 2")
+  if (nargin == 1 || nargin > 4)
+    print_usage ();
   endif
 
+  ## Shortcut for empty options structures
   if (isempty (ode_opt))
-    if (nargin == 2)
-      res = [];
-      return
+    if (nargin < 3)
+      val = [];
+    else
+      val = default;
     endif
-    res = default;
-    return
+    return;
   endif
 
   if (! isstruct (ode_opt))
-    error ("OdePkg:InvalidArgument",
-           "first input argument must be a valid ODE_STRUCT.");
-  endif
-
-  if (! ischar (field))
-    error ("OdePkg:InvalidArgument",
-           "second input argument must be a string.");
-  endif
-
-  if (nargin == 2)
-    default = [];
+    error ("odeget: ODE_OPT must be a valid ODE_STRUCT");
+  elseif (! ischar (field))
+    error ("odeget: FIELD must be a string");
   endif
 
-  if ((nargin == 4)
-      && strcmp (lower (deblank (opt)), "fast"))
-    if (isfield (ode_opt, field))
-      res = ode_opt.(field);
-    else
-      res = default;
-    endif
-    return
+  if (nargin == 4 && strcmpi (opt, "fast"))
+    try
+      val = ode_opt.(field);
+    catch
+      val = default;
+    end_try_catch
+    return;
   endif
 
-  if ((nargin == 4)
-      && strcmp (lower (deblank (opt)), "fast_not_empty"))
-    if (isfield (ode_opt, field)
-        && ! isempty (ode_opt.(field)) )
-      res = ode_opt.(field);
-    else
-      res = default;
-    endif
-    return
+  if (nargin == 4 && strcmpi (opt, "fast_not_empty"))
+    try
+      val = ode_opt.(field);
+      if (isempty (val))
+        val = default;
+      endif
+    catch
+      val = default;
+    end_try_catch
+    return;
   endif
 
   ## check if the given struct is a valid OdePkg struct
@@ -110,43 +102,44 @@
   while (1)
     pos = fuzzy_compare (field, options);
 
-    if (size (pos, 1) == 0) # no matching for the given option
+    if (isempty (pos))  # no match for the given option
       if (nargin == 2)
-        error ("OdePkg:InvalidArgument",
-               "invalid property. No property found with name '%s'.", field);
+        error ("odeget: invalid property. No property found with name '%s'",
+               field);
       endif
       warning ("odeget:NoExactMatching",
                "no property found with name '%s'. ",
                "Assuming default value.", field);
-      res = default;
-      return
+      val = default;
+      return;
     endif
 
-    if (size (pos, 1) == 1) # one matching
+    if (rows (pos) == 1)  # one matching
       if (! strcmp (lower (deblank (field)),
                     lower (deblank (options(pos,:)))) )
-        warning ("OdePkg:InvalidArgument",
+        warning ("odeget:InvalidArgument",
                  "no exact matching for '%s'. ",
-                 "Assuming you was intending '%s'.",
+                 "Assuming you were intending '%s'.",
                  field, deblank (options(pos,:)));
       endif
-      res = ode_opt.(deblank (options(pos,:)));
-      if (isempty (res))
-        res = default;
-        return
+      val = ode_opt.(deblank (options(pos,:)));
+      if (isempty (val))
+        val = default;
       endif
-      return
+      return;
     endif
 
+    ## FIXME: Do we really need interactive selection?
+    ##        Matlab doesn't appear to offer this.
     ## if there are more matching, ask the user to be more precise
-    warning ("OdePkg:InvalidArgument", ...
+    warning ("OdePkg:InvalidArgument",
              "no exact matching for '%s'. %d possible fields were found.",
-             field, size (pos, 1));
-    for j = 1:(size (pos, 1))
-      fprintf ("%s\n", deblank (options(pos(j),:)));
+             field, rows (pos));
+    for j = 1:(rows (pos))
+      printf ("%s\n", deblank (options(pos(j),:)));
     endfor
     do
-      fprintf ("Please insert field name again.\n");
+      printf ("Please insert field name again.\n");
       field = input ("New field name: ");
     until (ischar (field))
   endwhile
@@ -156,22 +149,23 @@
 
 %!demo
 %! # Return the manually changed value RelTol of the OdePkg options
-%! # strutcure A.  If RelTol wouldn't have been changed then an
+%! # structure A.  If RelTol wouldn't have been changed then an
 %! # empty matrix value would have been returned.
 %!
 %! A = odeset ("RelTol", 1e-1, "AbsTol", 1e-2);
 %! odeget (A, "RelTol", [])
 
-%! ## Turn off output of warning messages for all tests, turn them on
-%! ## again if the last test is called
-%!  warning ("off", "OdePkg:InvalidArgument");
-%!test assert (odeget (odeset (), "RelTol"), []);
-%!test assert (odeget (odeset (), "RelTol", 10), 10);
-%!test assert (odeget (odeset (), "Stats"), []);
-%!test assert (odeget (odeset (), "Stats", "on"), "on");
-%!test assert (odeget (odeset (), "AbsTol", 1.e-6, "fast"), []);
-%!test assert (odeget (odeset (), "AbsTol", 1.e-6, "fast_not_empty"), 1.e-6);
-%!test assert (odeget (odeset (), "AbsTol", 1e-9), 1e-9);
-%!
-%!  warning ("on", "OdePkg:InvalidArgument");
+%!test
+%! wstate = warning ("off", "OdePkg:InvalidArgument");
+%! unwind_protect
+%!   assert (odeget (odeset (), "RelTol"), []);
+%!   assert (odeget (odeset (), "RelTol", 10), 10);
+%!   assert (odeget (odeset (), "Stats"), []);
+%!   assert (odeget (odeset (), "Stats", "on"), "on");
+%!   assert (odeget (odeset (), "AbsTol", 1e-6, "fast"), []);
+%!   assert (odeget (odeset (), "AbsTol", 1e-6, "fast_not_empty"), 1e-6);
+%!   assert (odeget (odeset (), "AbsTol", 1e-9), 1e-9);
+%! unwind_protect_cleanup
+%!   warning (wstate);
+%! end_unwind_protect