Add a useful package (from Source forge) for octave

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

diff --git a/octave_packages/nurbs-1.3.6/kntuniform.m b/octave_packages/nurbs-1.3.6/kntuniform.m
new file mode 100644 (file)
index 0000000..2e6df46
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+++ b/octave_packages/nurbs-1.3.6/kntuniform.m
@@ -0,0 +1,52 @@
+% KNTUNIFORM: generate uniform open knot vectors in the reference domain.
+%
+%   [csi, zeta] = kntuniform (num, degree, regularity)
+%
+% INPUT:
+%     
+%     num:        number of breaks (in each direction)
+%     degree:     polynomial degree (in each direction)
+%     regularity: global regularity (in each direction)
+%
+% OUTPUT:
+%
+%     csi:  knots
+%     zeta: breaks = knots without repetitions
+% 
+% Copyright (C) 2009, 2010 Carlo de Falco
+% Copyright (C) 2011 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 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/>.
+
+function [csi, zeta] = kntuniform (num, degree, regularity)
+  
+  if (numel(num)~=numel(degree) || numel(num)~=numel(regularity))
+    error('kntuniform: num, degree and regularity must have the same length')
+  else
+    for idim=1:numel(num)
+      zeta{idim} = linspace (0, 1, num(idim));
+      rep  = degree(idim) - regularity(idim);
+      if (rep > 0)
+        csi{idim}  = [zeros(1, degree(idim)+1-rep)...
+          reshape(repmat(zeta{idim}, rep, 1), 1, []) ones(1, degree(idim)+1-rep)];
+      else
+        error ('kntuniform: regularity requested is too high')
+      end
+    end
+    if (numel(num) == 1)
+      csi = csi{1};
+      zeta = zeta{1};
+    end
+  end
+end