Add a useful package (from Source forge) for octave

[CreaPhase.git] / octave_packages / nurbs-1.3.6 / numbasisfun.m

diff --git a/octave_packages/nurbs-1.3.6/numbasisfun.m b/octave_packages/nurbs-1.3.6/numbasisfun.m
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+++ b/octave_packages/nurbs-1.3.6/numbasisfun.m
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+function B = numbasisfun (iv, uv, p, U)
+
+% NUMBASISFUN:  List non-zero Basis functions for B-Spline in a given knot-span
+%
+% Calling Sequence:
+% 
+%   N = numbasisfun(i,u,p,U)
+%   
+%    INPUT:
+%   
+%      i - knot span  ( from FindSpan() )
+%      u - parametric point
+%      p - spline degree
+%      U - knot sequence
+%   
+%    OUTPUT:
+%   
+%      N - Basis functions (numel(u)x(p+1))
+%   
+%    Copyright (C) 2009 Carlo de Falco
+%
+%    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 2 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/>.
+
+B = bsxfun (@(a, b) a+b,iv-p, (0:p).').';
+
+end
+
+%!test
+%!  n = 3; 
+%!  U = [0 0 0 1/2 1 1 1]; 
+%!  p = 2; 
+%!  u = linspace (0, 1, 10);  
+%!  s = findspan (n, p, u, U); 
+%!  Bref = [0   0   0   0   0   1   1   1   1   1; ...
+%!          1   1   1   1   1   2   2   2   2   2; ...
+%!          2   2   2   2   2   3   3   3   3   3].';
+%!  B = numbasisfun (s, u, p, U);
+%!  assert (B, Bref)
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