# arrowhead ,,in the middle'' of the line (arc) in psmatrix

E. Krishnan ekmath at md5.vsnl.net.in
Sun Dec 3 18:12:06 CET 2000

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On Sat, 2 Dec 2000, Jan Krupa wrote:

> -----------------------------------------------------------------------------
> This is the PSTricks mailing list, devoted to discussions about computational
> graphics in (La)TeX using the PSTricks package from Timothy van Zandt.
> For help using this mailing list, see instructions at the end of message.
> -----------------------------------------------------------------------------
>
>
> Q1:
> I would like to draw in diagram a line (or curve or arc)
> which connects two nodes and  the line (or curve) is to be with
> arrowhead not at the end (or beginning) of the line (or curve)
> but in the middle of the line, more precisely somewhere between
> the beginning and the end of the line (arc).
> I use %\psmatrix  and %\ncline and %\ncarc
> e.g. node1 ---->---- node2
>
> It is easy to draw such line or arc with arrowhead in the middle
> outside psmatrix but I need them in diagram so I need to use
> e.g. psmatrix.
>
> Q2: How to set different rowsep and colsep for different
> part of psmatrix? E.g.
> rowsep between 1st and 2nd row is 2cm but between 2nd and 3rd is 3cm.
> Similar for column.
>
>
> Jan

A quick solution for the first problem seems to be to insert an empty node
in between with a small negative nodesep such as

\begin{psmatrix}
a&\pnode{x}&b
\ncline[arrows=->]{1,1}{1,2}
\ncline[nodesep=-1pt]{1,2}{1,3}
\end{psmatrix}

As for the second problem, a separation of 1cm. between the first two rows
and a separation of 3cm. between the second row and the third can be got
by inserting some empty rows. For example,

\begin{psmatrix}[rowsep=1cm]
a&b\\
&&\\
c&d\\
&&\\
&&\\
e&f
\end{psmatrix}

Krishnan

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