[pstricks] How to show a specific point of a function's curve?

[Jean-Côme Charpentier]

Le 23/01/2011 19:33, Herbert Voss a écrit :
> Am 23.01.2011 19:11, schrieb Denis Bitouzé:
>
>> What would be the best way to show the point of the curve (with a qdisk
>> on the point and two parallel lines for its x- and y-values) just by
>> specifying its x-value?

   Argh! Not see the herbert Solution before I post the other message!

>    \qdisk(*3 {x^2/10}){2pt}% or \pnode(*3 {x^2/10}){Fx}

   Didn't know about this * function!  I have just searched string '{*' 
in pstricks, pstricks-add, pst-plot, pst-node, and pst-3d documentation 
and there is nothing about it.  I have the bad feeling I miss something 
somewhere...

   Jean-Côme