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

[Herbert Voss]

Am 24.01.2011 10:30, schrieb 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...

page 19 in http://mirror.ctan.org/graphics/pstricks/base/doc/pst-news08.pdf

it is defined in pstricks.tex

Herbert