[pstricks] graph like-Thomae function

[Michael Sharpe]

On Sep 24, 2011, at 2:27 PM, Hamed Al-Sulami wrote:

> Hi all,
>  
> I try to imetate the code for Thomae function to graph like Thomae function F(p/q)=sin(1/sqrt(q)).
> What I got does not look right and I'm not sure what did I do wrong.
>  
> Here is my try
>  
> \documentclass{article}
> \usepackage{pstricks-add}
> \usepackage{multido}
> \makeatletter
> \def\psThomae{\pst at object{psThomae}}
> \def\psThomae at i(#1,#2)#3{%
>   \addbefore at par{dotsize=1pt}
>   \begin at ClosedObj
>   \addto at pscode{
>     1 1 #3 {
>       dup
>       /ipSave ED % save loop value
>       /ip ED  % dito
>       1 1 #3 {  
>         dup  
>         /iqSave ED % sabve loop value
>         /iq ED  % dito
>         {
>           iq 0 le { exit } if
>           ip iq mod
>           /ip iq def
>           /iq ED
>         } loop
>         ip 1 eq {
>           /xVal ipSave iqSave div def
>           xVal #1 ge { xVal #2 le {
>             \psk at dotsize
>             \@nameuse{psds@\psk at dotstyle}
>             \pst at usecolor\pslinecolor xVal 1 iqSave sqrt  div RadtoDeg sin \tx at ScreenCoor                
>             2 copy moveto Dot } if } if
>         } if
>       } for
>     } for
>   }%
>   \end at ClosedObj%
> }
> \makeatother
> \begin{document}
> \begin{center}
>    \psset{unit=4cm,dotsize=1pt 0}
>    \begin{pspicture}(2.5,1.5)
>      \psaxes{->}(0,0)(2.5,1.5)
>      \psThomae(0,2){300}
>    \end{pspicture}
> \end{center}
> \end{document}
>  
>  
> Thanks a lot
>  

I don't see any problem with this. With your variant, the smallest non-zero value the function can take is close to 1/\sqrt{300} \approx 0.06, and the graph bears this out.

Michael