X-Git-Url: https://git.creatis.insa-lyon.fr/pubgit/?p=CreaPhase.git;a=blobdiff_plain;f=octave_packages%2Fgeometry-1.5.0%2Fgeom2d%2FcreateBasisTransform.m;fp=octave_packages%2Fgeometry-1.5.0%2Fgeom2d%2FcreateBasisTransform.m;h=312da94e3328af8103a85869f3ba008fe4b002b5;hp=0000000000000000000000000000000000000000;hb=c880e8788dfc484bf23ce13fa2787f2c6bca4863;hpb=1705066eceaaea976f010f669ce8e972f3734b05 diff --git a/octave_packages/geometry-1.5.0/geom2d/createBasisTransform.m b/octave_packages/geometry-1.5.0/geom2d/createBasisTransform.m new file mode 100644 index 0000000..312da94 --- /dev/null +++ b/octave_packages/geometry-1.5.0/geom2d/createBasisTransform.m @@ -0,0 +1,108 @@ +%% Copyright (c) 2011, INRA +%% 2010-2011, David Legland +%% 2011 Adapted to Octave by Juan Pablo Carbajal +%% +%% All rights reserved. +%% (simplified BSD License) +%% +%% Redistribution and use in @var{source} and binary forms, with or without +%% modification, are permitted provided that the following conditions are met: +%% +%% 1. Redistributions of @var{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{T} = } createBasisTransfrom (@var{@var{target}}) +%% @deftypefnx {Function File} {@var{T} = } createBasisTransfrom (@var{@var{source}}, @var{@var{target}}) +%% Compute matrix for transforming a basis into another basis +%% +%% With only one input arguemnt, assumes the @var{source} is the standard (Oij) basis, with origin at (0,0), +%% first direction vector equal to (1,0) and second direction vector +%% equal to (0,1). Otherwise @var{@var{source}} specifies the @var{source} basis. +%% +%% Both @var{source} and @var{target} represent basis, in the following form: +%% [x0 y0 ex1 ey1 ex2 ey2] +%% [y0 y0] is the origin of the basis, [ex1 ey1] is the first direction +%% vector, and [ex2 ey2] is the second direction vector. +%% +%% The result @var{T} is a 3-by-3 matrix such that a point expressed with +%% coordinates of the first basis will be represented by new coordinates +%% @code{P2 = transformPoint(P1, @var{T})} in the @var{target} basis. +%% +%% Example +%% @example +%% % standard basis transform +%% src = [0 0 1 0 0 1]; +%% % @var{target} transform, just a rotation by atan(2/3) followed by a scaling +%% tgt = [0 0 .75 .5 -.5 .75]; +%% % compute transform +%% trans = createBasisTransform(src, tgt); +%% % transform the point (.25,1.25) into the point (1,1) +%% p1 = [.25 1.25]; +%% p2 = transformPoint(p1, trans) +%% ans = +%% 1 1 +%% @end example +%% +%% @seealso{transforms2d} +%% @end deftypefn + +function transfo = createBasisTransform(source, target) + + % init basis transform to identity + t1 = eye(3); + t2 = eye(3); + + if nargin==2 + % from source to reference basis + t1(1:2, 1) = source(3:4); + t1(1:2, 2) = source(5:6); + t1(1:2, 3) = source(1:2); + else + % if only one input, use first input as target basis, and leave the + % first matrix to identity + target = source; + end + + % from reference to target basis + t2(1:2, 1) = target(3:4); + t2(1:2, 2) = target(5:6); + t2(1:2, 3) = target(1:2); + + % compute transfo + % same as: transfo = inv(t2)*t1; + transfo = t2\t1; + +endfunction + +%!demo +%! % standard basis transform +%! src = [0 0 1 0 0 1]; +%! % target transform, just a rotation by atan(2/3) followed by a scaling +%! tgt = [0 0 .75 .5 -.5 .75]; +%! % compute transform +%! trans = createBasisTransform(src, tgt); +%! % transform the point (.25,1.25) into the point (1,1) +%! p1 = [.25 1.25]; +%! p2 = transformPoint(p1, trans) +