--- a
+++ b/inst/km2nm.m
@@ -0,0 +1,34 @@
+## Copyright (C) 2014 Eugenio Gianniti <eugenio.gianniti@mail.polimi.it>
+##
+## This program is free software; you can redistribute it and/or modify it
+## under the terms of the GNU General Public License as published by
+## the Free Software Foundation; either version 3 of the License, or (at
+## your option) any later version.
+##
+## This program is distributed in the hope that it will be useful, but
+## WITHOUT ANY WARRANTY; without even the implied warranty of
+## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+## General Public License for more details.
+##
+## You should have received a copy of the GNU General Public License
+## along with this program; see the file COPYING.  If not, see
+## <http://www.gnu.org/licenses/>.
+
+## -*- texinfo -*-
+## @deftypefn {Function File} {} km2nm (@var{km})
+## Convert kilometers into nautical miles.
+##
+## @seealso{km2sm, nm2km, nm2sm, sm2km, sm2nm}
+## @end deftypefn
+
+## Author: Eugenio Gianniti <eugenio.gianniti@mail.polimi.it>
+
+function nm = km2nm (km)
+  if (nargin != 1)
+    print_usage ();
+  endif
+  persistent ratio = unitsratio ("nautical mile", "kilometer");
+  nm = km * ratio;
+endfunction
+
+%!assert (km2nm(1.852),1)