# 3D figure with pst-3Dplot

I'm trying to plot a simple math function in 3D using the package pst-3dplot. The function is z = 1/(1+a*exp(-b*y)) * (c * (1 - exp(d*x)) * (1 - exp(e*(x-f)))).

I tried the following:

\def\PsEuler{2.71828182846}
\psset{xunit=0.5cm,yunit=0.5cm}
\begin{pspicture}(-5,0)(10,10)
\psset{Beta=15,nameX=$x_1$,nameY=$x_2$,nameZ=$x_3$}
\pstThreeDCoor[IIIDticks,IIIDlabels,xMin=0,xMax=120,yMin=0,yMax=1,zMin=0,zMax=12,Dx=1,Dy=0.01,Dz=1]
\infixtoRPN{ 1/(1+300*\PsEuler^(-10*y)) * (11.06 * (1 - \PsEuler^(-0.214*x)) * (1 - \PsEuler^(0.02667*(x-113)))) }
\psplotThreeD[yPlotpoints=50,xPlotpoints=50,hiddenLine=true](0,120)(0,1){\RPN}
\end{pspicture}


The function is correctly shown between [0,1] on the y-axis, but I didn't succeed in streching the y-axis. I have 10 units in both the x-z axis and 1 unit in the y-axis and the function looks like very "crushed" in this direction. I tried the Dy = 0.1 in order to "strech" the y-axis and plot 10 units of values 0.1. It doesn't work. If I set

\psplotThreeD[...](0,120)(0,10){\RPN}


it plots the function on the y-axis from 0 to 1 (step 0.1) but the function is not correctly drawn (in fact the result is the function between [0,10] in the y-axis but with an incorrect y-scale).

I double checked the function with Matlab and it is correctly plotted. Any suggestions would be greatly appreciated.

it makes more sense to use pst-solides3dif you want hidden lines. For a better view I choosed 10*x and y/10 for the coordinates. The x/y-values for the function are divided/multiplied to get the (0...120)(0...1) interval

\documentclass[pstricks]{standalone}
\usepackage{pst-solides3d}
\begin{document}

\psset{viewpoint=30 50 10 rtp2xyz,Decran=15}

\begin{pspicture}(-6.5,-5)(5,7)
\psSurface[algebraic,ngrid=0.2 0.2 ](0,0)(12,10){
1/(1+300*Euler^(-y))*(11.06*(1 -Euler^(-2.14*x))*(1-Euler^(0.02667*(10*x-113))))}
\end{pspicture}

\end{document} the same with axes:

\documentclass[pstricks]{standalone}
\usepackage{pst-solides3d}
\begin{document}
\psset{viewpoint=40 60 10 rtp2xyz,Decran=15}

\begin{pspicture}(-6,-5)(5,6)
\psSurface[algebraic,ngrid=0.25 0.25,axesboxed,Zmax=10 ](0,0)(12,10){
1/(1+300*Euler^(-y))*(11.06*(1 -Euler^(-2.14*x))*(1-Euler^(0.02667*(10*x-113))))}
\end{pspicture}

\end{document} • Great, very impressive. Did not knew pst-solides3d but sounds very good. Thanks for the tip – Grasshoper Mar 25 '13 at 18:23