<html><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; ">
Jurgen et al,<div><br></div><div>I would not pick points P and Q that lie on the boundary. So I would want the arrows at the end of the lines where the lines exit on a boundary of the grid.</div><div><br></div><div>When I teach, I tell the students that the arrow has the same meaning as the ellipses at the end of this sequence:</div><div><br></div><div>1, 3, 5, 7, ...</div><div><br></div><div>They mean "etcetera." The arrow at the end of the line means much the same thing. Enough of the pattern has been established so that you can intuit the rest of the behavior of the function. For example, it moves up and to the right indefinitely.</div><div><br></div><div>This type of instruction comes in handy when discussing the domain and range of functions from a graphical viewpoint with the students. We do a number of examples where we have segments, rays, and lines, and they have different effects on the domain (or range).</div><div><br></div><div>For example, see the discussion on Domain and Range in the Intermediate Algebra Text we wrote for our students:</div><div><br></div><div><a href="http://msenux.redwoods.edu/IntAlgText/chapter2/section3.pdf">http://msenux.redwoods.edu/IntAlgText/chapter2/section3.pdf</a></div><div><br></div><div>D.</div><div><br></div><div><br><div><div>On Dec 29, 2008, at 12:17 PM, Juergen Gilg wrote:</div><br class="Apple-interchange-newline"><blockquote type="cite"> <font face="Myriad Pro">Dear Arnold,<br> <br> where should appear the arrowheads, if the line ends in: (-5,-5), (-5,5), (5,-5), (-5,5) in the 4 CORNERS of your grid??? <br> Inmidst of the circlepoint = not visible, due to the radius of the circle...<br> <br> Just a general question: Why do you like to have arrowheads in a functionplot? Any didactial aspects? I am definitely not used to that. To show that the line does not end at that point?<br> <br> I always imagine when having an arrowhead, that there is a DIRECTION... Just to widen my horizon of didactics.<br> <br> Regard,<br> <br> Juergen<br> <br> </font><br> David Arnold wrote: <blockquote cite="mid:1420E242-210E-446A-9D44-1739B44DAADE@suddenlink.net" type="cite">Jurgen, <div><br> </div> <div>Good ideas here. I would not thought of this solution.</div> <div><br> </div> <div>One point: At my end, the lines don't have arrows at each end. They're line segments.</div> <div><br> </div> <div>Is there a fix for this?</div> <div><br> </div> <div>D.</div> <div><br> </div> <br> <hr size="4" width="90%"><br> <div><br> <div> <div>On Dec 29, 2008, at 11:55 AM, Juergen Gilg wrote:</div> <br class="Apple-interchange-newline"> <blockquote type="cite"> Dear David,<br> <br> couldn't solve the problem with 2 arrowhead at the end of the lines drawn, however the rest should work fine.<br> <blockquote cite="mid:75312BDB-3C9E-4889-BB03-F935A656FE73@suddenlink.net" type="cite"> <pre wrap="">Looking for ideas.
</pre> </blockquote> <pre class="moz-signature" cols="65"><font color="#003300">\documentclass{article}
\usepackage{pstricks,pstricks-add}
\begin{document}
\pagestyle{empty}
\newcommand{\DaveArnold}[4]{%
\psset{unit=0.5}
\begin{pspicture}(-6,-6)(6,6)
\psgrid[gridcolor=lightgray,gridlabels=0pt,subgriddiv=1](0,0)(-5,-5)(5,5)
\psaxes[labels=none,ticks=none]{->}(0,0)(-5.5,-5.5)(5.5,5.5)
\Cnode[radius=0.1cm,fillstyle=solid,fillcolor=blue,linecolor=blue](#1,#2){A}
\Cnode[radius=0.1cm,fillstyle=solid,fillcolor=blue,linecolor=blue](#3,#4){B}
\psclip{\psframe[linestyle=none](-5,-5)(5,5)}
\ncline[nodesep=10cm,linecolor=blue]{<->}{A}{B}
\endpsclip
\uput[0](5.5,0){$x$}
\uput[90](0,5.5){$y$}
\end{pspicture}
\resetOptions
}
\DaveArnold{1}{2}{-3}{5}
%First Argument x-Koordinate Point A
%Second Argument y-Koordinate Point A
%Third Argument x-Koordinate Point B
%Fourth Argument y-Koordinate Point B
\DaveArnold{-1}{-2}{3}{3}
\DaveArnold{-5}{-5}{1}{2}
%NO PROBLEM to so produce vertical and horizontal lines as well.
\end{document} </font>
</pre> <br> Regards,<br> <br> Juergen<br> <div style="margin: 0px;">_______________________________________________</div> <div style="margin: 0px;">PSTricks mailing list</div> <div style="margin: 0px;"><a moz-do-not-send="true" href="mailto:PSTricks@tug.org">PSTricks@tug.org</a></div> <div style="margin: 0px;"><a moz-do-not-send="true" href="http://tug.org/mailman/listinfo/pstricks">http://tug.org/mailman/listinfo/pstricks</a></div> </blockquote> </div> <br> </div> <pre wrap=""><hr size="4" width="90%">_______________________________________________
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</pre> </blockquote> <br> <pre class="moz-signature" cols="65">--
Jürgen Gilg
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-------------------------------------
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