Add a useful package (from Source forge) for octave

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

diff --git a/octave_packages/nurbs-1.3.6/vecscale.m b/octave_packages/nurbs-1.3.6/vecscale.m
new file mode 100644 (file)
index 0000000..4e050ec
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+++ b/octave_packages/nurbs-1.3.6/vecscale.m
@@ -0,0 +1,65 @@
+function ss = vecscale(vector)
+
+%
+% VECSCALE: Transformation matrix for a scaling.
+% 
+% Calling Sequence:
+% 
+%   ss = vecscale(svec)
+% 
+% INPUT:
+% 
+%   svec    : A vectors defining the scaling along the x,y and z axes.
+%             i.e. [sx, sy, sy]
+%
+% OUTPUT:
+% 
+%   ss     : Scaling Transformation Matrix
+% 
+% Description:
+% 
+%   Returns a (4x4) Transformation matrix for scaling.
+% 
+%   The matrix is:
+% 
+%         [ sx  0   0   0]
+%         [ 0   sy  0   0]
+%         [ 0   0   sz  0]
+%         [ 0   0   0   1]
+% 
+% Example:
+% 
+%   Scale up the NURBS line (0.0,0.0,0.0) - (1.0,1.0,1.0) by 3 along
+%   the x-axis, 2 along the y-axis and 4 along the z-axis.
+% 
+%   line = nrbline([0.0 0.0 0.0],[1.0 1.0 1.0]);
+%   trans = vecscale([3.0 2.0 4.0]);
+%   sline = nrbtform(line, trans);
+% 
+% See also:
+% 
+%    nrbtform
+%
+%    Copyright (C) 2000 Mark Spink, 2007 Daniel Claxton
+%
+%    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/>.
+
+if nargin < 1
+  error('Scaling vector not specified');
+end   
+
+s = [vector(:);0;0];
+ss = [s(1) 0 0 0; 0 s(2) 0 0; 0 0 s(3) 0; 0 0 0 1];
+
+end