gnuplot-info

[Gnuplot-info] 2D cross-section of 3D plot - possible?

[Paweł R. <go...@gm...>]

Hello,

I'm currently working on some fluid modelling and get a bunch of 4D
data - mostly velocity field in cartesian coordinates.

I'm wondering if it is possible to make a 3D plot of this data by
limiting the range of 4th data column?
For example to plot v(x,z), but only for a certain value of y.

A simpler but essentially the same problem is to make a 2D plot from
3D data - eg. to plot v(z) for a specified value of y.

I know I can make a 3D plot with a range limit for one axis, but it's
still a 3D plot which contains only 2D data, so it's not what I want.

Anyone can help?

greetings,
Paweł

Re: [Gnuplot-info] 2D cross-section of 3D plot - possible?

[Hans-Bernhard B. <HBB...@t-...>]

Paweł Rumian wrote:

> I'm wondering if it is possible to make a 3D plot of this data by
> limiting the range of 4th data column?

No.  gnuplot doesn't contain an isosurface or isovolume extraction 
engine.  We only have an isocurve extractor, i.e. the implementation of 
'set contours'.

> A simpler but essentially the same problem is to make a 2D plot from
> 3D data - eg. to plot v(z) for a specified value of y.

That is something 'set contour' can do for you.

Re: [Gnuplot-info] 2D cross-section of 3D plot - possible?

[Paweł R. <go...@gm...>]

2010/5/26 Hans-Bernhard Bröker <HBB...@t-...>:
> Paweł Rumian wrote:
>
>> I'm wondering if it is possible to make a 3D plot of this data by
>> limiting the range of 4th data column?
>
> No.  gnuplot doesn't contain an isosurface or isovolume extraction engine.
>  We only have an isocurve extractor, i.e. the implementation of 'set
> contours'.
>
>> A simpler but essentially the same problem is to make a 2D plot from
>> 3D data - eg. to plot v(z) for a specified value of y.
>
> That is something 'set contour' can do for you.
>

Thanks a lot!

Paweł