<html><head></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; ">The following code (full tex file attached)<div><br></div><div><blockquote type="cite"><div><span class="Apple-tab-span" style="white-space:pre"><font class="Apple-style-span" color="#000000">        </font></span><font class="Apple-style-span" color="#000000">\begin{pspicture}(-2,-2)(2,3.5)</font></div><div><span class="Apple-tab-span" style="white-space:pre"><font class="Apple-style-span" color="#000000">                </font></span><font class="Apple-style-span" color="#000000">\psset{unit=0.75}</font></div><div><span class="Apple-tab-span" style="white-space:pre"><font class="Apple-style-span" color="#000000">                </font></span><font class="Apple-style-span" color="#000000">\psset{lightsrc=10 20 -30, viewpoint= 50 60 25</font></div><div><span class="Apple-tab-span" style="white-space:pre"><font class="Apple-style-span" color="#000000">                        </font></span><font class="Apple-style-span" color="#000000">rtp2xyz, Decran=50}</font></div><div><span class="Apple-tab-span" style="white-space:pre"><font class="Apple-style-span" color="#000000">                </font></span><font class="Apple-style-span" color="#000000">\psSolid[object=calottesphere,</font></div><div><span class="Apple-tab-span" style="white-space:pre"><font class="Apple-style-span" color="#000000">                                </font></span><font class="Apple-style-span" color="#000000">r=3, ngrid = 12 15,</font></div><div><span class="Apple-tab-span" style="white-space:pre"><font class="Apple-style-span" color="#000000">                                </font></span><font class="Apple-style-span" color="#000000">fillcolor=lightgray,</font></div><div><span class="Apple-tab-span" style="white-space:pre"><font class="Apple-style-span" color="#000000">                                </font></span><font class="Apple-style-span" color="#000000">incolor=white,</font></div><div><span class="Apple-tab-span" style="white-space:pre"><font class="Apple-style-span" color="#000000">                                </font></span><font class="Apple-style-span" color="#000000">theta=30, phi=0,</font></div><div><span class="Apple-tab-span" style="white-space:pre"><font class="Apple-style-span" color="#000000">                                </font></span><font class="Apple-style-span" color="#000000">hollow](0,0,0)%</font></div><div><span class="Apple-tab-span" style="white-space:pre"><font class="Apple-style-span" color="#000000">                </font></span><font class="Apple-style-span" color="#000000">\axesIIID(3,3,3.6)(6,6,5)</font></div><div><span class="Apple-tab-span" style="white-space:pre"><font class="Apple-style-span" color="#000000">                </font></span></div><div><font class="Apple-style-span" color="#000000">%</font><span class="Apple-tab-span" style="white-space:pre"><font class="Apple-style-span" color="#000000">                </font></span><font class="Apple-style-span" color="#000000">\psset{linecolor=lightgray}</font></div><div><span class="Apple-tab-span" style="white-space:pre"><font class="Apple-style-span" color="#000000">                </font></span><font class="Apple-style-span" color="#000000">\multido{\rp=70+10}{4}{%</font></div><div><span class="Apple-tab-span" style="white-space:pre"><font class="Apple-style-span" color="#000000">                        </font></span><font class="Apple-style-span" color="#000000">\multido{\rt=175+10}{13}{%</font></div><div><span class="Apple-tab-span" style="white-space:pre"><font class="Apple-style-span" color="#000000">                                </font></span><font class="Apple-style-span" color="#000000">\vecatThree%</font></div><div><span class="Apple-tab-span" style="white-space:pre"><font class="Apple-style-span" color="#000000">                                        </font></span><font class="Apple-style-span" color="#000000">{3 \rp\space sin \rt\space cos mul mul}</font></div><div><span class="Apple-tab-span" style="white-space:pre"><font class="Apple-style-span" color="#000000">                                        </font></span><font class="Apple-style-span" color="#000000">{3 \rp\space sin \rt\space sin mul mul}</font></div><div><span class="Apple-tab-span" style="white-space:pre"><font class="Apple-style-span" color="#000000">                                        </font></span><font class="Apple-style-span" color="#000000">{3 \rp\space cos mul}</font></div><div><span class="Apple-tab-span" style="white-space:pre"><font class="Apple-style-span" color="#000000">                                        </font></span><font class="Apple-style-span" color="#000000">{1.0 \rp\space sin \rt\space cos mul mul neg}</font></div><div><span class="Apple-tab-span" style="white-space:pre"><font class="Apple-style-span" color="#000000">                                        </font></span><font class="Apple-style-span" color="#000000">{1.0 \rp\space sin \rt\space sin mul mul neg}</font></div><div><span class="Apple-tab-span" style="white-space:pre"><font class="Apple-style-span" color="#000000">                                        </font></span><font class="Apple-style-span" color="#000000">{1.0 \rp\space cos mul neg}</font></div><div><span class="Apple-tab-span" style="white-space:pre"><font class="Apple-style-span" color="#000000">                        </font></span><font class="Apple-style-span" color="#000000">}</font></div><div><span class="Apple-tab-span" style="white-space:pre"><font class="Apple-style-span" color="#000000">                </font></span><font class="Apple-style-span" color="#000000">}</font></div><div><span class="Apple-tab-span" style="white-space:pre"><font class="Apple-style-span" color="#000000">        </font></span><font class="Apple-style-span" color="#000000">\end{pspicture}</font></div></blockquote><div><br></div><div>together with the definition&nbsp;</div><div><blockquote type="cite"><div><span class="Apple-tab-span" style="white-space:pre"><font class="Apple-style-span" color="#000000">        </font></span><font class="Apple-style-span" color="#000000">\newcommand{\vecatThree}[6]{\pstThreeDLine[arrows=-&gt;]%</font></div><div><span class="Apple-tab-span" style="white-space:pre"><font class="Apple-style-span" color="#000000">                </font></span><font class="Apple-style-span" color="#000000">(#1\space, &nbsp;#2\space, &nbsp;#3\space)</font></div><div><span class="Apple-tab-span" style="white-space:pre"><font class="Apple-style-span" color="#000000">                </font></span><font class="Apple-style-span" color="#000000">(#1\space #4\space add, #2\space #5\space add, #3\space #6\space add)</font></div><div><span class="Apple-tab-span" style="white-space:pre"><font class="Apple-style-span" color="#000000">        </font></span><font class="Apple-style-span" color="#000000">}</font></div><div><span class="Apple-tab-span" style="white-space:pre"><font class="Apple-style-span" color="#000000">                </font></span><font class="Apple-style-span" color="#000000">% arrow pinned to (#1,#2,#3) with components (#4,#5,#6) (postscript version)</font></div><div><br></div></blockquote><br></div><div>yields the attached image. &nbsp;Everything is fine, except that I am puzzled by the two gaps in the upper z axis.</div><div>Any explanation?</div><div><br></div><div><br></div><div><br></div><div></div></div></body></html>