[pstricks] another confusion about \parametricplotThreeD

[Herbert Voss]

Am 02.01.2012 16:20, schrieb Nitecki, Zbigniew H.:
> Thanks---I had forgotten whether the previous example had been \parametricplotThreeD or just \parametricplot.
> The example I sent this time did not have the extra jul (I wanted t^2, not t^3).
>
> In any case, unless I am being very blind, my real question in this post is different:  why is the green curve,
> coded as
> \parametricplotThreeD[linecolor=green](-3,3){%
> t
> 0
> t dup t mul 36 add sqrt 3 div

your code is wrong! you have with
t dup t mul => t t t mul
three t!

If you want t² then use
t dup mul => t t
or
t t mul
or as I already pointed out "t 2 exp"
or, which is easier to prevent such errors

\parametricplotThreeD[linecolor=green,algebraic](-3,3){%
   t | 0 | sqrt(t^2+36)/3 }

Herbert