/usr/share/octave/packages/geometry-1.7.0/geom2d/crackPattern2.m is in octave-geometry 1.7.0-1build1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 | ## Copyright (C) 2004-2011 David Legland <david.legland@grignon.inra.fr>
## Copyright (C) 2004-2011 INRA - CEPIA Nantes - MIAJ (Jouy-en-Josas)
## Copyright (C) 2012 Adapted to Octave by Juan Pablo Carbajal <carbajal@ifi.uzh.ch>
## All rights reserved.
##
## 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 AUTHOR 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.
## -*- texinfo -*-
## @deftypefn {Function File} {@var{e} = } crackPattern2 (@var{box}, @var{points}, @var{alpha})
## Create a (bounded) crack pattern tessellation
##
## E = crackPattern2(BOX, POINTS, ALPHA)
## create a crack propagation pattern wit following parameters :
## - pattern is bounded by area BOX which is a polygon.
## - each crack originates from points given in POINTS
## - directions of each crack is given by a [NxM] array ALPHA, where M is
## the number of rays emanating from each seed/
## - a crack stop when it reaches another already created crack.
## - all cracks stop when they reach the border of the frame, given by box
## (a serie of 4 points).
## The result is a collection of edges, in the form [x1 y1 x2 y2].
##
## E = crackPattern2(BOX, POINTS, ALPHA, SPEED)
## Also specify speed of propagation of each crack.
##
##
## See the result with :
## figure;
## drawEdge(E);
##
## @seealso{drawEdge}
## @end deftypefn
function edges = crackPattern2(box, points, alpha, varargin)
if ~isempty(varargin)
speed = varargin{1};
else
speed = ones(size(points, 1), 1);
end
# Compute line equations for each initial crack.
# The 'Inf' at the end correspond to the position of the limit.
# If an intersection point is found with another line, but whose position
# is after this value, this means that another crack stopped it before it
# reach the intersection point.
NP = size(points, 1);
lines = zeros(0, 5);
for i=1:size(alpha, 2)
lines = [lines; points speed.*cos(alpha(:,i)) speed.*sin(alpha(:,i)) Inf*ones(NP, 1)];
end
NL = size(lines, 1);
# initialize lines for borders, but assign a very high speed, to be sure
# borders will stop all cracks.
dx = (box([2 3 4 1],1)-box([1 2 3 4],1))*max(speed)*5;
dy = (box([2 3 4 1],2)-box([1 2 3 4],2))*max(speed)*5;
# add borders to the lines set
lines = [lines ; createLine(box, dx, dy) Inf*ones(4,1)];
edges = zeros(0, 4);
while true
modif = 0;
# try to update each line
for i=1:NL
# initialize first point of edge
edges(i, 1:2) = lines(i, 1:2);
# compute intersections with all other lines
pi = intersectLines(lines(i,:), lines);
# compute position of all intersection points on the current line
pos = linePosition(pi, lines(i,:));
# consider points to the right (positive position), and sort them
indr = find(pos>1e-12 & pos~=Inf);
[posr, indr2] = sort(pos(indr));
# look for the closest intersection to the right
for i2=1:length(indr2)
# index of intersected line
il = indr(indr2(i2));
# position of point relative to intersected line
pos2 = linePosition(pi(il, :), lines(il, :));
# depending on the sign of position, tests if the line2 can
# stop the current line, or if it was stopped before
if pos2>0
if pos2<abs(posr(i2)) && pos2<lines(il, 5)
if lines(i, 5) ~= posr(i2)
edges(i, 3:4) = pi(il,:);
lines(i, 5) = posr(i2);
modif = 1;
end
break;
end
end
end # end processing of right points of the line
end # end processing of all lines
# break the infinite loop if no more modification was made
if ~modif
break;
end
end
# add edges of the surronding box.
edges = [edges ; box(1,:) box(2,:) ; box(2,:) box(3,:); ...
box(3,:) box(4,:) ; box(4,:) box(1,:) ];
endfunction
|