[pstricks] help about frenet frame
Herbert Voss
Herbert.Voss at FU-Berlin.DE
Sat Dec 20 22:30:51 CET 2008
Aydin USTUN schrieb:
> Dear all,I am trying to plot the tangent, normal, and bi-normal unit vectors at several points along the space curve. I applied the following code, but the tangent and bi-normal unit vectors point to the incorrect directions. I could not find that where is the problem? Please help.Thanks,Aydin\documentclass[12pt]{article} % A. Ustun 19.10.2006\usepackage[latin5]{inputenc}\usepackage{pst-3dplot}\SpecialCoor\pagestyle{empty}\begin{document}\psset{arrowlength=2.5,arrowinset=0,unit=2}\begin{pspicture}(0,0)(4,4)%\psgrid(-3,-3)(3,3)\psset{Alpha=70,Beta=30}\pstThreeDCoor[linecolor=gray,linewidth=1pt,xMin=0,yMin=0,zMin=0,xMax=3,yMax=3.1,zMax=2.5]\parametricplotThreeD[plotstyle=curve,xPlotpoints=200](0,840){ t cos t sin t 300 div}% unit tangent vector: e1\parametricplotThreeD[plotstyle=line,arrows={->},xPlotpoints=2,yPlotpoints=4,linecolor=red](0,1)(0,660){% f0 t df/dt 1/||df/dt|| f0+t*e1 %%%%%%%%% % %%%%%%
%%% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%% %%%%%%% u cos t u sin neg 1 1 300 div 2 exp add sqrt div mul add % for x u sin t u cos 1 1 300 div 2 exp add sqrt div mul add % for y u 300 div t 1 300 div 1 1 300 div 2 exp add sqrt div mul add % for z}% unit normal vector: e2\parametricplotThreeD[plotstyle=line,arrows={->},xPlotpoints=2,yPlotpoints=4,linecolor=blue](0,1)(0,660){% f0 t de1/dt f0+t*e2 %%%%%%%%% % %%%%%%%%% %%%%%%% u cos t u cos neg mul add % for x u sin t u sin neg mul add % for y u 300 div t 0 mul add % for z}% unit tangent vector: e3\parametricplotThreeD[plotstyle=line,arrows={->},xPlotpoints=2,yPlotpoints=4,linecolor=green](0,1)(0,660){% f0 t e1xe2 1/||df/dt|| f0+t*e1 %%%%%%%%% % %%%%%%%%% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%% %%%%%%% u cos t
u sin 300 div 1 1 300 div 2 exp add sqrt div mul add % for x u sin t u cos 300 div neg 1 1 300 div 2 exp add sqrt div mul add % for y u 300 div t 1 1 1 300 div 2 exp add sqrt div mul add % for z}\end{pspicture}\end{document}
please insert line breaks into your code. It is very difficult to
see the command lines.
I do not really understand your problem. In the starting point the
tangent is parallel to the y-axis, the normal vector parrallel to
the z-axis and the bi normal anti parallel to the x-axis. What is wrong
with this directions?
Herbert
More information about the PSTricks
mailing list