Many thanks, I didn't think at a parametric curve.
Loïc
Le mercredi 23 juillet 2008 à 00:15 +0200, HansBernhard Bröker a
écrit :
> Loïc wrote:
>
> > set table "out"
> > set xrange [0:10] reverse
> > plot x**2
>
> [...]
>
> > Hence, x are in increasing mode, and not decreasing as I wish.
> >
> > Is it a bug ?
>
> No. There's no promise of the range reversal affecting sampling order.
> It affects the relation between coordinates and positions on a graph,
> not the order in which those positions are visited. That ordering is
> generally unimportant, since you couldn't spot the difference in the
> resulting image anyway.
>
> The table driver makes that a bit mor complicated, of course. But, like
> with so many problems, parametric mode helps:
>
> gnuplot> set table ; set parametric ; set samples 15
> gnuplot> f_x(t) = 10  t
> gnuplot> plot [0:10] f_x(t), f_x(t)**2
>
> #Curve 0 of 1, 15 points
> #x y type
> 10 100 i
> 9.28571 86.2245 i
> 8.57143 73.4694 i
> 7.85714 61.7347 i
> 7.14286 51.0204 i
> 6.42857 41.3265 i
> 5.71429 32.6531 i
> 5 25 i
> 4.28571 18.3673 i
> 3.57143 12.7551 i
> 2.85714 8.16327 i
> 2.14286 4.59184 i
> 1.42857 2.04082 i
> 0.714286 0.510204 i
> 0 0 i
>
>
