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  • Voxels from expression

    From Al Greynolds@21:1/5 to All on Fri Apr 30 06:22:49 2021
    Can the new voxels capability display an isosurface of an expression, i.e. a given function of x,y,z?

    Al

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  • From Gavin Buxton@21:1/5 to Al Greynolds on Fri Apr 30 07:08:51 2021
    On Friday, April 30, 2021 at 9:22:50 AM UTC-4, Al Greynolds wrote:
    Can the new voxels capability display an isosurface of an expression, i.e. a given function of x,y,z?

    Al

    Apparently so....

    https://lwn.net/Articles/828761/

    although I've not played around with it. Looks awesome though!

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  • From Al Greynolds@21:1/5 to Gavin Buxton on Fri Apr 30 08:40:34 2021
    On Friday, April 30, 2021 at 7:08:54 AM UTC-7, Gavin Buxton wrote:
    On Friday, April 30, 2021 at 9:22:50 AM UTC-4, Al Greynolds wrote:
    Can the new voxels capability display an isosurface of an expression, i.e. a given function of x,y,z?

    Al
    Apparently so....

    https://lwn.net/Articles/828761/

    although I've not played around with it. Looks awesome though!

    Here's what I'm trying to do:

    R=1
    L=8
    n=2
    h=3
    m=3
    f(x,y,z)=x**2+(y-h*(z/L)**m)**2-(R*(1-(z/L)**n))**2
    set vgrid $wh size 100
    set vxrange [-R:R]
    set vyrange [-R:h+R]
    set vzrange [0:L]
    vfill ?
    splot $wh w isosurface level 0

    Why does vfill require a file or datablock as a source? Why can''t my function f be used as easily as plot and splot allow plotting expressions/functions instead of files or datablocks?

    Al

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  • From Gavin Buxton@21:1/5 to Al Greynolds on Sat May 1 07:02:11 2021
    On Friday, April 30, 2021 at 11:40:35 AM UTC-4, Al Greynolds wrote:
    On Friday, April 30, 2021 at 7:08:54 AM UTC-7, Gavin Buxton wrote:
    On Friday, April 30, 2021 at 9:22:50 AM UTC-4, Al Greynolds wrote:
    Can the new voxels capability display an isosurface of an expression, i.e. a given function of x,y,z?

    Al
    Apparently so....

    https://lwn.net/Articles/828761/

    although I've not played around with it. Looks awesome though!
    Here's what I'm trying to do:

    R=1
    L=8
    n=2
    h=3
    m=3
    f(x,y,z)=x**2+(y-h*(z/L)**m)**2-(R*(1-(z/L)**n))**2
    set vgrid $wh size 100
    set vxrange [-R:R]
    set vyrange [-R:h+R]
    set vzrange [0:L]
    vfill ?
    splot $wh w isosurface level 0

    Why does vfill require a file or datablock as a source? Why can''t my function f be used as easily as plot and splot allow plotting expressions/functions instead of files or datablocks?

    Al

    Hopefully someone else can help, but you used to be able to set terminal as 'table' and output functions to a file. Assuming videos requires discrete points. Hopefully someone has more experience with voxels. Thanks for asking the question though, as I
    didn't this was a new feature!

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  • From Al Greynolds@21:1/5 to All on Tue May 4 06:59:39 2021
    OK I sort of got what i wanted, but had to begrudgingly resort to separately creating a file of point data for vfill. However, even though all inputs are symmetric about the x=0 plane, the resulting isosurface is not. I can provide the script and data
    files if anyones interested.

    Al

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