[pstricks] ArrowInside {pstricks-add}

[Michael Sharpe]

On Oct 28, 2009, at 12:49 PM, Scourat Mikita wrote:

> Hi everybody.
> I've got some questions about pstricks-add. About arrows inside  
> objects.
> Does "ArrowInside" and the related options work with \psplot or  
> \psellipse (etc)? If not, how to draw a plot with lots of inside  
> arrows?
> [I've got such a code: \psellipse 
> [linewidth=1pt,nodesep=1pt,ArrowInside=->,ArrowInsideNo=1](0,0) 
> (0.73,0.4). And it doesn't work...]

It appears from the pstricks-add documentation that ArrowInside works  
so far only with \psline, \psbezier and their close relatives. The  
following example shows how you could get similar functionality in any  
curve, with a little additional work. You will need the pst-nodeExtras  
package at

http://math.ucsd.edu/~msharpe/pst-nodeExtras.zip

\documentclass[dvips]{amsart}
\usepackage[dvipsnames]{pstricks}
\usepackage{pst-all}
\usepackage{pst-nodeExtras}
\pagestyle{empty}
\begin{document}
\thispagestyle{empty}
\begin{pspicture}[showgrid=true](-.5,-.5)(8.5,4.5)
\def\myfn{4+4*cos(t) |2+2*sin(t)}% ellipse
\curvepnodes[plotpoints=50]{0}{3.145}\myfn{P}%defines nodes P0..P49  
along curve
\psset{linewidth=1pt,arrowscale=2}
\parametricplot[algebraic]{0}{3.145}\myfn
\psline[ArrowInside=->](P24)(P25)%half way
\end{pspicture}
\end{document}

Michael