[pstricks] computed coordinates

[Zbigniew Nitecki]

I want to draw a series of concentric ellipses with successively larger axes.  The following

			\begin{pspicture}(-3,-2.5)(3,3)
				\multido{\rc=0+0.5}{9}{\psellipse[linecolor=green](\rc,\rc\space 2 div)}
			\end{pspicture}

yields the error message

! Illegal unit of measure (pt inserted).
<to be read again> 
                   2
l.24 ...pse[linecolor=green](\rc,\rc\space 2 div)}

What is missing, since if instead I had written \psellipse(2,1) I would not have gotten this message?


Zbigniew Nitecki
Department of Mathematics
Tufts University
Medford, MA 02155

telephones:
Office    (617)627-3843
Dept.    (617)627-3234
Dept. fax    (617)627-3966
http://www.tufts.edu/~znitecki/

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