Add a useful package (from Source forge) for octave

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

diff --git a/octave_packages/miscellaneous-1.1.0/normr.m b/octave_packages/miscellaneous-1.1.0/normr.m
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+## 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} = } normr (@var{M})
+## Normalize the rows of a matrix to a length of 1 and return the matrix.
+##
+## @example
+##   M=[1,2; 3,4];
+##   normr(M)
+##
+##   ans =
+##
+##   0.44721   0.89443
+##   0.60000   0.80000
+##
+## @end example
+## @seealso{normc}
+## @end deftypefn
+
+function X = normr(M)
+  if (1 != nargin)
+    print_usage;
+  endif
+  
+  norm = sqrt(sum(M .* conj(M),2));
+  X = diag(1./norm) *  M;
+endfunction
+
+%% test for real and complex matrices
+%!test
+%! M = [1,2; 3,4];
+%! expected = [0.447213595499958, 0.894427190999916; 0.6, 0.8];
+%! assert(normr(M), expected, eps);
+
+%!test
+%! M = [i,2*i; 3*I,4*I];
+%! expected = [0.447213595499958*I, 0.894427190999916*I; 0.6*I, 0.8*I];
+%! assert(normr(M), expected, eps);
+
+%!test
+%! M = [1+2*I, 3+4*I; 5+6*I, 7+8*I];
+%! expected = [0.182574185835055 + 0.365148371670111i, 0.547722557505166 + 0.730296743340221i
+%!             0.379049021789452 + 0.454858826147342i, 0.530668630505232 + 0.606478434863123i];
+%! assert(normr(M), expected, 10*eps);
+
+%% test error/usage handling
+%!error <normr> normr();