/usr/share/octave/packages/geometry-1.7.0/geom2d/createCircle.m is in octave-geometry 1.7.0-1build1.
This file is owned by root:root, with mode 0o644.
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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 | ## 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{circle} = } createCircle (@var{p1}, @var{p2}, @var{p3})
## @deftypefnx {Function File} {@var{circle} = } createCircle (@var{p1}, @var{p2})
## Create a circle from 2 or 3 points.
##
## Creates the circle passing through the 3 given points.
## C is a 1x3 array of the form: [XC YX R].
##
## When two points are given, creates the circle whith center @var{p1} and passing
## throuh the point @var{p2}.
##
## Works also when input are point arrays the same size, in this case the
## result has as many lines as the point arrays.
##
## Example
##
## @example
## # Draw a circle passing through 3 points.
## p1 = [10 15];
## p2 = [15 20];
## p3 = [10 25];
## circle = createCircle(p1, p2, p3);
## figure; hold on; axis equal; axis([0 50 0 50]);
## drawPoint([p1 ; p2; p3]);
## drawCircle(circle);
## @end example
##
## @seealso{circles2d, createDirectedCircle}
## @end deftypefn
function circle = createCircle(varargin)
if nargin == 2
# inputs are the center and a point on the circle
p1 = varargin{1};
p2 = varargin{2};
x0 = p1(:,1);
y0 = p1(:,2);
r = hypot((p2(:,1)-x0), (p2(:,2)-y0));
elseif nargin == 3
# inputs are three points on the circle
p1 = varargin{1};
p2 = varargin{2};
p3 = varargin{3};
# compute circle center
line1 = medianLine(p1, p2);
line2 = medianLine(p1, p3);
point = intersectLines(line1, line2);
x0 = point(:, 1);
y0 = point(:, 2);
# circle radius
r = hypot((p1(:,1)-x0), (p1(:,2)-y0));
end
# create array for returning result
circle = [x0 y0 r];
endfunction
%!shared privpath
%! privpath = [fileparts(which('geom2d_Contents')) filesep() 'private'];
%!test
%! addpath (privpath,'-end')
%! p1 = [10 15];
%! p2 = [15 20];
%! p3 = [10 25];
%! exp = [10 20 5];
%! circle = createCircle(p1, p2, p3);
%! assertEqual(exp, circle);
%! circle = createCircle(p3, p1, p2);
%! assertEqual(exp, circle);
%! circle = createCircle(p2, p3, p1);
%! assertEqual(exp, circle);
%! rmpath (privpath);
%!test
%! addpath (privpath,'-end')
%! p1 = [10 15];
%! p2 = [15 20];
%! p3 = [10 25];
%! exp = [10 20 5];
%! p1 = [p1; p1+10; p1+20; p1-5];
%! p2 = [p2; p2+10; p2+20; p2-5];
%! p3 = [p3; p3+10; p3+20; p3-5];
%! exp = repmat(exp, 4, 1) + [0 0 0;10 10 0;20 20 0;-5 -5 0];
%! circle = createCircle(p1, p2, p3);
%! assertEqual(exp, circle);
%! circle = createCircle(p3, p1, p2);
%! assertEqual(exp, circle);
%! circle = createCircle(p2, p3, p1);
%! assertEqual(exp, circle);
%! rmpath (privpath);
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