MATLAB: This code does Not work

b-splinecodenurbs

function [B, id] = nrbbasisfun (points, nrb)
% NRBBASISFUN: Basis functions for NURBS % % Calling Sequence: % % B = nrbbasisfun (u, crv) % B = nrbbasisfun ({u, v}, srf) % [B, N] = nrbbasisfun ({u, v}, srf) % [B, N] = nrbbasisfun (p, srf) % % INPUT: % % u or p(1,:,:) – parametric points along u direction % v or p(2,:,:) – parametric points along v direction % crv – NURBS curve % srf – NURBS surface % % OUTPUT: % % B – Value of the basis functions at the points % size(B)=[numel(u),(p+1)] for curves % or [numel(u)*numel(v), (p+1)*(q+1)] for surfaces % % N – Indices of the basis functions that are nonvanishing at each % point. size(N) == size(B) % % % 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 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<2) ...
    || (nargout>2) ...
    || (~isstruct(nrb)) ...
    || (iscell(points) && ~iscell(nrb.knots)) ...
    || (~iscell(points) && iscell(nrb.knots) && (size(points,1)~=2)) ...
    || (~iscell(nrb.knots) && (nargout>1)) ...
    )
  error('Incorrect input arguments in nrbbasisfun');
end
if (~iscell(nrb.knots))         %%NURBS curve
    [B, id] = nrb_crv_basisfun__ (points, nrb);
elseif size(nrb.knots,2) == 2 %%NURBS surface
  if (iscell(points))
    [v, u] = meshgrid(points{2}, points{1});
    p = [u(:), v(:)]';
  else
    p = points;
  end
    [B, id] = nrb_srf_basisfun__ (p, nrb); 
else                            %%NURBS volume
  error('The function nrbbasisfun is not yet ready for volumes')
end
end
%!demo %! U = [0 0 0 0 1 1 1 1]; %! x = [0 1/3 2/3 1] ; %! y = [0 0 0 0]; %! w = [1 1 1 1]; %! nrb = nrbmak ([x;y;y;w], U); %! u = linspace(0, 1, 30); %! B = nrbbasisfun (u, nrb); %! xplot = sum(bsxfun(@(x,y) x.*y, B, x),2); %! plot(xplot, B) %! title('Cubic Bernstein polynomials') %! hold off
Is there anyone can help me? I'm trying to do the demo above and I'm having eror message. Please help.

Best Answer

The error message means, that the function nrb_crv_basisfun__ is not found. Did you installed it and if so, has the corresponding folder been added to the path?
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