Keywords: Tubular neighborhood.png Illustration of en Tubular neighborhood Made with en Matlab Oleg Alexandrov 03 01 1 June 2007 UTC Public domain Created with MATLAB Source code MATLAB <source lang matlab > illustration of tubular neighborhood function main f inline 'sin x ' 'x' ; will construct a tubular neighborhood of this curve a 0; b 2 pi; N 100; X linspace a b N ; consider N points in the interval a b Y f X ; the curve ll 3; length of lines perpendicular to the curve lls 0 3; smaller subsegments thin_line 2; thick_line 4; will draw lines perpendicular to the graph of Y f X at points separted by length of 'spacing' spacing 0 033; M floor spacing N ; colors red 0 867 0 06 0 14; blue 0 129 205/256; green 0 200 70/256; figure 1 ; clf; hold on; axis equal; axis off; plot the lines for k 1 N p k-1 M+2; if p > N break; end the normal to the curve at X p Y p Normal - Y p+1 -Y p-1 X p+1 -X p-1 ; Normal Normal/norm Normal ; plot X p -ll Normal 1 X p +ll Normal 1 Y p -ll Normal 2 Y p +ll Normal 2 'color' green 'linewidth' thin_line plot X p -lls Normal 1 X p +lls Normal 1 Y p -lls Normal 2 Y p +lls Normal 2 'color' red 'linewidth' 0 7 thick_line end plot the curve plot X Y 'linewidth' thick_line ; saveas gcf 'Tubular_neighborhood eps' 'psc2' </source> Images with Matlab source code tubular neighborhood Files by User Oleg Alexandrov from en wikipedia math |