[pstricks] recursion

[Robert Salvador]

Good evening everybody!
 
I want to do a recursive calculation in a LaTeX-document with following
PSTricks drawing. So I have defined a variable
\def\x{0.0 }
Now I want to assign a new value to this variable (within a \whildo
loop). This new value is calculated from the old one like (simplyfied):
\def\x{\x 1 add }
But this doesn't work (TeX capacity exceeded!)
 
I tried to fix the problem using a second variable
 
\def\x{0.0 }
\whiledo{ ... }
\let\temp\x
\def\x{\temp  1 add }
% now pstricks drawing ...
}
Doesn't work neither!
 
Has anybody an idea what to do?
 
Many thanks in advance!
Robert