Add a useful package (from Source forge) for octave

[CreaPhase.git] / octave_packages / miscellaneous-1.1.0 / normc.m

diff --git a/octave_packages/miscellaneous-1.1.0/normc.m b/octave_packages/miscellaneous-1.1.0/normc.m
new file mode 100644 (file)
index 0000000..931a496
--- /dev/null
+++ b/octave_packages/miscellaneous-1.1.0/normc.m
@@ -0,0 +1,61 @@
+## Copyright (C) 2011 Thomas Weber <tweber@debian.org>
+##
+## 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; if not, see <http://www.gnu.org/licenses/>.
+
+## -*- texinfo -*-
+## @deftypefn {Function File} {@var{x} =} normc (@var{M})
+## Normalize the columns of a matrix to a length of 1 and return the matrix.
+##
+## @example
+##   M=[1,2; 3,4];
+##   normc(M)
+##
+##   ans =
+##
+##   0.31623   0.44721
+##   0.94868   0.89443
+##
+## @end example
+## @seealso{normr}
+## @end deftypefn
+
+function X = normc(M)
+  if (1 != nargin)
+    print_usage;
+  endif
+
+  X = normr(M.').';
+endfunction
+
+%% test for real and complex matrices
+%!test
+%! M = [1,2; 3,4];
+%! expected = [0.316227766016838, 0.447213595499958;
+%!             0.948683298050514, 0.894427190999916];
+%! assert(normc(M), expected, eps);
+
+%!test
+%! M = [i,2*i; 3*I,4*I];
+%! expected = [0.316227766016838*I, 0.447213595499958*I;
+%!             0.948683298050514*I, 0.894427190999916*I];
+%! assert(normc(M), expected, eps);
+
+%!test
+%! M = [1+2*I, 3+4*I; 5+6*I, 7+8*I];
+%! expected = [0.123091490979333 + 0.246182981958665i, 0.255376959227625 + 0.340502612303499i;
+%!             0.615457454896664 + 0.738548945875996i, 0.595879571531124 + 0.681005224606999i];
+%! assert(normc(M), expected, 10*eps);
+
+%% test error/usage handling
+%!error <normc> normc();