<html><head></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><div><div></div><div>Note that despite the change in viewpoint (the only change between the three pspictures the output appears identical.</div><div><br></div><div>I wanted to ask about this, so I tried to create a minimal example by taking out all the package calls that seemed irrelevant, and wrote the package calls for pst in the order</div><div>once dictated to me by Herbert (to avoid another conflict). That resulted in this code:</div><div><br></div><div>*************************************************************************************************************************************************************</div><div><div>\documentclass[11pt]{article}</div><div>%\usepackage{pstricks, pst-plot, pst-math, pst-3dplot}</div><div>%\usepackage{pst-grad, pst-func, pst-text}</div><div>%\usepackage{pstricks-add}</div><div>%\usepackage{pst-3d}</div><div>\usepackage{pst-solides3d, pst-3dplot, pst-math,pstricks-add}</div><div>\usepackage{pst-3d}</div><div><br></div><div>\title{Brief Article}</div><div>\author{The Author}</div><div>%\date{} % Activate to display a given date or no date</div><div><br></div><div>\begin{document}</div><div>\maketitle</div><div>%</div><div><span class="Apple-tab-span" style="white-space:pre"> </span>\begin{figure}[htbp]</div><div><span class="Apple-tab-span" style="white-space:pre"> </span>\begin{center}</div><div>%<span class="Apple-tab-span" style="white-space:pre"> </span>\begin{pspicture}(-2,-2)(2,2)</div><div>%<span class="Apple-tab-span" style="white-space:pre"> </span>\psline{<->}(-1.5,0)(1.5,0)\uput[r](1.5,0){$x$}</div><div>%<span class="Apple-tab-span" style="white-space:pre"> </span>\psline{<->}(0,-1.5)(0,1.5)\uput[u](0,1.5){$y$}</div><div>%<span class="Apple-tab-span" style="white-space:pre"> </span>\parametricplot[plotpoints=200]{0}{360}{%</div><div>%<span class="Apple-tab-span" style="white-space:pre"> </span>1 t 3 mul cos 0.2 mul add t 2 mul cos mul</div><div>%<span class="Apple-tab-span" style="white-space:pre"> </span>1 t 3 mul cos 0.2 mul add t 2 mul sin mul</div><div>%<span class="Apple-tab-span" style="white-space:pre"> </span>}</div><div>%<span class="Apple-tab-span" style="white-space:pre"> </span>\end{pspicture}</div><div><span class="Apple-tab-span" style="white-space:pre"> </span>\begin{pspicture}(-2,-2)(2,2)</div><div><span class="Apple-tab-span" style="white-space:pre"> </span>\psset{viewpoint=1 1 1}</div><div><span class="Apple-tab-span" style="white-space:pre"> </span>\pstThreeDCoor[xMax=2.0, yMax=2.0, zMax=2.0]</div><div><span class="Apple-tab-span" style="white-space:pre"> </span>\parametricplotThreeD[xPlotpoints=200, hiddenLine=true](0,360){%</div><div><span class="Apple-tab-span" style="white-space:pre"> </span>1 t 3 mul cos 0.2 mul add t 2 mul cos mul</div><div><span class="Apple-tab-span" style="white-space:pre"> </span>1 t 3 mul cos 0.2 mul add t 2 mul sin mul</div><div><span class="Apple-tab-span" style="white-space:pre"> </span>t 3 mul sin</div><div><span class="Apple-tab-span" style="white-space:pre"> </span>}</div><div><span class="Apple-tab-span" style="white-space:pre"> </span>\end{pspicture}</div><div><span class="Apple-tab-span" style="white-space:pre"> </span>\qquad</div><div><span class="Apple-tab-span" style="white-space:pre"> </span>\begin{pspicture}(-2,-2)(2,2)</div><div><span class="Apple-tab-span" style="white-space:pre"> </span>\psset{viewpoint=0.5 0.5 1}</div><div><span class="Apple-tab-span" style="white-space:pre"> </span>\pstThreeDCoor[xMax=2.0, yMax=2.0, zMax=2.0]</div><div><span class="Apple-tab-span" style="white-space:pre"> </span>\parametricplotThreeD[xPlotpoints=200, hiddenLine=true](0,360){%</div><div><span class="Apple-tab-span" style="white-space:pre"> </span>1 t 3 mul cos 0.2 mul add t 2 mul cos mul</div><div><span class="Apple-tab-span" style="white-space:pre"> </span>1 t 3 mul cos 0.2 mul add t 2 mul sin mul</div><div><span class="Apple-tab-span" style="white-space:pre"> </span>t 3 mul sin</div><div><span class="Apple-tab-span" style="white-space:pre"> </span>}</div><div><span class="Apple-tab-span" style="white-space:pre"> </span>\end{pspicture}</div><div><span class="Apple-tab-span" style="white-space:pre"> </span>\qquad</div><div><span class="Apple-tab-span" style="white-space:pre"> </span>\begin{pspicture}(-2,-2)(2,2)</div><div><span class="Apple-tab-span" style="white-space:pre"> </span>\psset{viewpoint=0.1 0.1 1}</div><div><span class="Apple-tab-span" style="white-space:pre"> </span>\pstThreeDCoor[xMax=2.0, yMax=2.0, zMax=2.0]</div><div><span class="Apple-tab-span" style="white-space:pre"> </span>\parametricplotThreeD[xPlotpoints=200, hiddenLine=true](0,360){%</div><div><span class="Apple-tab-span" style="white-space:pre"> </span>1 t 3 mul cos 0.2 mul add t 2 mul cos mul</div><div><span class="Apple-tab-span" style="white-space:pre"> </span>1 t 3 mul cos 0.2 mul add t 2 mul sin mul</div><div><span class="Apple-tab-span" style="white-space:pre"> </span>t 3 mul sin</div><div><span class="Apple-tab-span" style="white-space:pre"> </span>}</div><div><span class="Apple-tab-span" style="white-space:pre"> </span>\end{pspicture}</div><div><span class="Apple-tab-span" style="white-space:pre"> </span>\caption{The Trefoil}</div><div><span class="Apple-tab-span" style="white-space:pre"> </span>\label{fig:bracelet}</div><div><span class="Apple-tab-span" style="white-space:pre"> </span>\end{center}</div><div><span class="Apple-tab-span" style="white-space:pre"> </span>\end{figure}</div><div><span class="Apple-tab-span" style="white-space:pre"> </span></div><div>\end{document}</div></div><div><br></div><div>***************************************************************************************************************************************</div><div><br></div><div>But running this produced the error</div><div><br></div><div><blockquote type="cite"><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; font: normal normal normal 10px/normal Monaco; ">! Undefined control sequence.</div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; font: normal normal normal 10px/normal Monaco; ">\XC@usec@lor ...\expandafter \c@lor@to@ps #1#2\@@ </div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; font: normal normal normal 10px/normal Monaco; "> \else \expandafter \expand...</div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; font: normal normal normal 10px/normal Monaco; ">l.29 <span class="Apple-tab-span" style="white-space:pre"> </span>\parametricplotThreeD</div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; font: normal normal normal 10px/normal Monaco; "> [xPlotpoints=200, hiddenLine=true](0,360){%</div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; font: normal normal normal 10px/normal Monaco; ">? </div></blockquote></div><div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; font: normal normal normal 10px/normal Monaco; "><br></div></div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; font: normal normal normal 10px/normal Monaco; "><font class="Apple-style-span" face="Helvetica" size="3"><span class="Apple-style-span" style="font-size: 12px;">The only change between the two versions was some erasing of commented stuff and changing the package calls.</span></font></div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; font: normal normal normal 10px/normal Monaco; "><font class="Apple-style-span" face="Helvetica" size="3"><span class="Apple-style-span" style="font-size: 12px;"><br></span></font></div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; font: normal normal normal 10px/normal Monaco; "><font class="Apple-style-span" face="Helvetica" size="3"><span class="Apple-style-span" style="font-size: 12px;">So I have two questions:</span></font></div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; font: normal normal normal 10px/normal Monaco; "><font class="Apple-style-span" face="Helvetica" size="3"><span class="Apple-style-span" style="font-size: 12px;">1. Why does the second version result in \parametricplotThreeD being undefined?</span></font></div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; font: normal normal normal 10px/normal Monaco; "><font class="Apple-style-span" face="Helvetica" size="3"><span class="Apple-style-span" style="font-size: 12px;">2. Why does viewpoint have no effect in my first version?</span></font></div><div>
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