X-Git-Url: https://git.creatis.insa-lyon.fr/pubgit/?p=CreaPhase.git;a=blobdiff_plain;f=octave_packages%2Fgeometry-1.5.0%2Fgeom2d%2FvectorNorm.m;fp=octave_packages%2Fgeometry-1.5.0%2Fgeom2d%2FvectorNorm.m;h=6ba1c6205f3f75c2e86b122bfaf3288f0a6a8ef0;hp=0000000000000000000000000000000000000000;hb=f5f7a74bd8a4900f0b797da6783be80e11a68d86;hpb=1705066eceaaea976f010f669ce8e972f3734b05 diff --git a/octave_packages/geometry-1.5.0/geom2d/vectorNorm.m b/octave_packages/geometry-1.5.0/geom2d/vectorNorm.m new file mode 100644 index 0000000..6ba1c62 --- /dev/null +++ b/octave_packages/geometry-1.5.0/geom2d/vectorNorm.m @@ -0,0 +1,114 @@ +%% Copyright (c) 2011, INRA +%% 2007-2011, David Legland +%% 2011 Adapted to Octave by Juan Pablo Carbajal +%% +%% All rights reserved. +%% (simplified BSD License) +%% +%% Redistribution and use in source and binary forms, with or without +%% modification, are permitted provided that the following conditions are met: +%% +%% 1. Redistributions of source code must retain the above copyright notice, this +%% list of conditions and the following disclaimer. +%% +%% 2. Redistributions in binary form must reproduce the above copyright notice, +%% this list of conditions and the following disclaimer in the documentation +%% and/or other materials provided with the distribution. +%% +%% THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" +%% AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE +%% IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE +%% ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE +%% LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR +%% CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF +%% SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS +%% INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN +%% CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) +%% ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE +%% POSSIBILITY OF SUCH DAMAGE. +%% +%% The views and conclusions contained in the software and documentation are +%% those of the authors and should not be interpreted as representing official +%% policies, either expressed or implied, of copyright holder. + +%% -*- texinfo -*- +%% @deftypefn {Function File} {@var{nm} = } vectorNorm (@var{v}) +%% @deftypefnx {Function File} {@var{nm} = } vectorNorm (@var{v},@var{n}) +%% Compute norm of a vector, or of a set of vectors +%% +%% Without extra arguments, returns the euclidean norm of vector V. +%% Optional argument @var{n} specifies the norm to use. N can be any value +%% greater than 0. +%% @table @samp +%% @item N=1 +%% City lock norm. +%% @item N=2 +%% Euclidean norm. +%% @item N=inf +%% Compute max coord. +%% @end table +%% +%% When @var{v} is a MxN array, compute norm for each vector of the array. +%% Vector are given as rows. Result is then a Mx1 array. +%% +%% Example +%% +%% @example +%% n1 = vectorNorm([3 4]) +%% n1 = +%% 5 +%% +%% n2 = vectorNorm([1, 10], inf) +%% n2 = +%% 10 +%% @end example +%% +%% @seealso{vectors2d, vectorAngle} +%% @end deftypefn + +function n = vectorNorm(v, varargin) + + % size of vector + dim = size(v); + + % extract the type of norm to compute + d = 2; + if ~isempty(varargin) + d = varargin{1}; + end + + if d==2 + % euclidean norm: sum of squared coordinates, and take square root + if dim(1)==1 || dim(2)==1 + n = sqrt(sum(v.*v)); + else + n = sqrt(sum(v.*v, 2)); + end + elseif d==1 + % absolute norm: sum of absolute coordinates + if dim(1)==1 || dim(2)==1 + n = sum(abs(v)); + else + n = sum(abs(v), 2); + end + elseif d==inf + % infinite norm: uses the maximal corodinate + if dim(1)==1 || dim(2)==1 + n = max(v); + else + n = max(v, [], 2); + end + else + % Other norms, use explicit but slower expression + if dim(1)==1 || dim(2)==1 + n = power(sum(power(v, d)), 1/d); + else + n = power(sum(power(v, d), 2), 1/d); + end + end + +endfunction + +%!assert (5, vectorNorm ([3 4])) +%!assert(10, vectorNorm ([1, 10], inf)) +