/usr/share/octave/packages/nurbs-1.3.13/nrbkntplot.m is in octave-nurbs 1.3.13-4.
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 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 | function nrbkntplot (nurbs)
% NRBKNTPLOT: Plot a NURBS entity with the knots subdivision.
%
% Calling Sequence:
%
% nrbkntplot(nurbs)
%
% INPUT:
%
% nurbs: NURBS curve, surface or volume, see nrbmak.
%
% Example:
%
% Plot the test surface with its knot vector
%
% nrbkntplot(nrbtestsrf)
%
% See also:
%
% nrbctrlplot
%
% Copyright (C) 2011, 2012 Rafael Vazquez
%
% 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/>.
if (nargin < 1)
error ('nrbkntplot: Need a NURBS to plot!');
end
% Default values
light='on';
cmap='summer';
colormap (cmap);
hold_flag = ishold;
if (iscell (nurbs.knots))
if (size (nurbs.knots,2) == 2) % plot a NURBS surface
nsub = 100;
nrbplot (nurbs, [nsub nsub], 'light', light, 'colormap', cmap);
hold on
% And plot the knots
knt1 = unique (nurbs.knots{1}(nurbs.order(1):end-nurbs.order(1)+1));
knt2 = unique (nurbs.knots{2}(nurbs.order(2):end-nurbs.order(2)+1));
p1 = nrbeval (nurbs, {knt1, linspace(knt2(1),knt2(end),nsub)});
p2 = nrbeval (nurbs, {linspace(knt1(1),knt1(end),nsub), knt2});
if (any (nurbs.coefs(3,:)))
% surface in a 3D space
for ii = 1:numel(knt1)
plot3 (squeeze(p1(1,ii,:)), squeeze(p1(2,ii,:)), squeeze(p1(3,ii,:)),'k');
end
for ii = 1:numel(knt2)
plot3 (squeeze(p2(1,:,ii)), squeeze(p2(2,:,ii)), squeeze(p2(3,:,ii)),'k');
end
else
% plain surface
for ii = 1:numel(knt1)
plot (squeeze(p1(1,ii,:)), squeeze (p1(2,ii,:)),'k');
end
for ii = 1:numel(knt2)
plot (p2(1,:,ii),p2(2,:,ii),'k');
end
end
elseif (size (nurbs.knots,2) == 3) % plot a NURBS volume
% Plot the boundaries
bnd = nrbextract (nurbs);
nrbkntplot (bnd(1));
hold on
for iface = 2:6
nrbkntplot (bnd(iface));
end
end
else % plot a NURBS curve
nsub = 1000;
nrbplot (nurbs, nsub);
hold on
% And plot the knots
order = nurbs.order;
p = nrbeval (nurbs, unique (nurbs.knots(order:end-order+1)));
if (any (nurbs.coefs(3,:))) % plot a 3D curve
plot3 (p(1,:), p(2,:), p(3,:), 'rx');
else % plot a 2D curve
plot (p(1,:), p(2,:), 'rx');
end
end
if (~hold_flag)
hold off
end
end
%!demo
%! crv = nrbtestcrv;
%! nrbkntplot(crv)
%! title('Test curve')
%! hold off
%!demo
%! sphere = nrbrevolve(nrbcirc(1,[],0.0,pi),[0.0 0.0 0.0],[1.0 0.0 0.0]);
%! nrbkntplot(sphere);
%! title('Ball and torus - surface construction by revolution');
%! hold on;
%! torus = nrbrevolve(nrbcirc(0.2,[0.9 1.0]),[0.0 0.0 0.0],[1.0 0.0 0.0]);
%! nrbkntplot(torus);
%! hold off
%!demo
%! knots = {[0 0 0 1/2 1 1 1] [0 0 0 1 1 1]...
%! [0 0 0 1/6 2/6 1/2 1/2 4/6 5/6 1 1 1]};
%!
%! coefs = [-1.0000 -0.9734 -0.7071 1.4290 1.0000 3.4172
%! 0 2.4172 0 0.0148 -2.0000 -1.9734
%! 0 2.0000 4.9623 9.4508 4.0000 2.0000
%! 1.0000 1.0000 0.7071 1.0000 1.0000 1.0000
%! -0.8536 0 -0.6036 1.9571 1.2071 3.5000
%! 0.3536 2.5000 0.2500 0.5429 -1.7071 -1.0000
%! 0 2.0000 4.4900 8.5444 3.4142 2.0000
%! 0.8536 1.0000 0.6036 1.0000 0.8536 1.0000
%! -0.3536 -4.0000 -0.2500 -1.2929 1.7071 1.0000
%! 0.8536 0 0.6036 -2.7071 -1.2071 -5.0000
%! 0 2.0000 4.4900 10.0711 3.4142 2.0000
%! 0.8536 1.0000 0.6036 1.0000 0.8536 1.0000
%! 0 -4.0000 0 0.7071 2.0000 5.0000
%! 1.0000 4.0000 0.7071 -0.7071 -1.0000 -5.0000
%! 0 2.0000 4.9623 14.4142 4.0000 2.0000
%! 1.0000 1.0000 0.7071 1.0000 1.0000 1.0000
%! -2.5000 -4.0000 -1.7678 0.7071 1.0000 5.0000
%! 0 4.0000 0 -0.7071 -3.5000 -5.0000
%! 0 2.0000 6.0418 14.4142 4.0000 2.0000
%! 1.0000 1.0000 0.7071 1.0000 1.0000 1.0000
%! -2.4379 0 -1.7238 2.7071 1.9527 5.0000
%! 0.9527 4.0000 0.6737 1.2929 -3.4379 -1.0000
%! 0 2.0000 6.6827 10.0711 4.0000 2.0000
%! 1.0000 1.0000 0.7071 1.0000 1.0000 1.0000
%! -0.9734 -1.0000 -0.6883 0.7071 3.4172 1.0000
%! 2.4172 0 1.7092 -1.4142 -1.9734 -2.0000
%! 0 4.0000 6.6827 4.9623 4.0000 0
%! 1.0000 1.0000 0.7071 0.7071 1.0000 1.0000
%! 0 -0.8536 0 0.8536 3.5000 1.2071
%! 2.5000 0.3536 1.7678 -1.2071 -1.0000 -1.7071
%! 0 3.4142 6.0418 4.4900 4.0000 0
%! 1.0000 0.8536 0.7071 0.6036 1.0000 0.8536
%! -4.0000 -0.3536 -2.8284 1.2071 1.0000 1.7071
%! 0 0.8536 0 -0.8536 -5.0000 -1.2071
%! 0 3.4142 7.1213 4.4900 4.0000 0
%! 1.0000 0.8536 0.7071 0.6036 1.0000 0.8536
%! -4.0000 0 -2.8284 1.4142 5.0000 2.0000
%! 4.0000 1.0000 2.8284 -0.7071 -5.0000 -1.0000
%! 0 4.0000 10.1924 4.9623 4.0000 0
%! 1.0000 1.0000 0.7071 0.7071 1.0000 1.0000
%! -4.0000 -2.5000 -2.8284 0.7071 5.0000 1.0000
%! 4.0000 0 2.8284 -2.4749 -5.0000 -3.5000
%! 0 4.0000 10.1924 6.0418 4.0000 0
%! 1.0000 1.0000 0.7071 0.7071 1.0000 1.0000
%! 0 -2.4379 0 1.3808 5.0000 1.9527
%! 4.0000 0.9527 2.8284 -2.4309 -1.0000 -3.4379
%! 0 4.0000 7.1213 6.6827 4.0000 0
%! 1.0000 1.0000 0.7071 0.7071 1.0000 1.0000
%! -1.0000 -0.9734 0.2071 2.4163 1.0000 3.4172
%! 0 2.4172 -1.2071 -1.3954 -2.0000 -1.9734
%! 2.0000 4.0000 7.0178 6.6827 2.0000 0
%! 1.0000 1.0000 1.0000 0.7071 1.0000 1.0000
%! -0.8536 0 0.3536 2.4749 1.2071 3.5000
%! 0.3536 2.5000 -0.8536 -0.7071 -1.7071 -1.0000
%! 1.7071 4.0000 6.3498 6.0418 1.7071 0
%! 0.8536 1.0000 0.8536 0.7071 0.8536 1.0000
%! -0.3536 -4.0000 0.8536 0.7071 1.7071 1.0000
%! 0.8536 0 -0.3536 -3.5355 -1.2071 -5.0000
%! 1.7071 4.0000 6.3498 7.1213 1.7071 0
%! 0.8536 1.0000 0.8536 0.7071 0.8536 1.0000
%! 0 -4.0000 1.2071 3.5355 2.0000 5.0000
%! 1.0000 4.0000 -0.2071 -3.5355 -1.0000 -5.0000
%! 2.0000 4.0000 7.0178 10.1924 2.0000 0
%! 1.0000 1.0000 1.0000 0.7071 1.0000 1.0000
%! -2.5000 -4.0000 -0.5429 3.5355 1.0000 5.0000
%! 0 4.0000 -1.9571 -3.5355 -3.5000 -5.0000
%! 2.0000 4.0000 8.5444 10.1924 2.0000 0
%! 1.0000 1.0000 1.0000 0.7071 1.0000 1.0000
%! -2.4379 0 -0.0355 3.5355 1.9527 5.0000
%! 0.9527 4.0000 -1.4497 -0.7071 -3.4379 -1.0000
%! 2.0000 4.0000 9.4508 7.1213 2.0000 0
%! 1.0000 1.0000 1.0000 0.7071 1.0000 1.0000];
%! coefs = reshape (coefs, 4, 4, 3, 9);
%! horseshoe = nrbmak (coefs, knots);
%! nrbkntplot (horseshoe);
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