Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Plotting 3D data

  1. Dec 9, 2007 #1
    I have a set of 3D data (i.e. a large file where each row contains three spatial coordinates) and I'd like to get a nice, smooth 3D object out of it. The objects are not surfaces, so it's not just plotting a function (i.e. to every (x,y) there exists more than one z).

    Does anyone have an idea which (freeware) application can deal with this kind of stuff? Thanks in advance.
     
  2. jcsd
  3. Dec 9, 2007 #2

    robphy

    User Avatar
    Science Advisor
    Homework Helper
    Gold Member

    Are you merely looking to effectively plot "pixels" or "voxels"?
    To get something "smooth" out of a collection of points, you probably have to provide some kind of interpolation scheme.
     
  4. Dec 9, 2007 #3
    Well, let's say I have some 1000 points which form (or should form) a ball, for example. What I want to get is a nice, smooth 3D ball. Is that possible?
     
  5. Dec 9, 2007 #4

    robphy

    User Avatar
    Science Advisor
    Homework Helper
    Gold Member

    You can try to run it through some kind of averaging scheme.
    You could do a surface fit to a sphere to determine the center and radius.
     
  6. Dec 9, 2007 #5
    yeah, but those objects are pretty crazy and really far away from spheres.
    what kind of averaging schemes do you mean?
     
  7. Dec 9, 2007 #6

    robphy

    User Avatar
    Science Advisor
    Homework Helper
    Gold Member

    What "objects" are you talking about?
    Didn't you just ask about a ball (whose surface is a sphere)?

    Here are some examples of interpolation:
    http://en.wikipedia.org/wiki/Interpolation
     
  8. Dec 9, 2007 #7
    :rolleyes:
    The ball was just an example. The objects that I'm working with are much complicated.

    I'm not really sure if interpolation is what I'm searching for.
     
  9. Dec 9, 2007 #8

    robphy

    User Avatar
    Science Advisor
    Homework Helper
    Gold Member

    How many points are you talking about?
    For a simple platform to get a first look at the data,
    try http://www.vpython.org
    to plot pixels (as boxes) in 3-D.
     
  10. Dec 9, 2007 #9
    It's about 30x30x30 points, more or less.
     
  11. Dec 9, 2007 #10

    robphy

    User Avatar
    Science Advisor
    Homework Helper
    Gold Member

    First try my suggestion above.
    If your points describe a surface, you could try some algorithm that triangulates it [which guesses how the sampled-points are possibly connected], then another algorithm that tries to find a smooth approximation of it... to be rendered on a finer grid.
     
  12. Sep 21, 2009 #11
    hi,
    i want to plot a set of 3-D data.
    i have 3 spatial co-ordinates (x, y, z) and then a physical quantity i have measured.
    Is there a straight forward free plotting package i could use to plot this data?

    thanks!
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?



Similar Discussions: Plotting 3D data
Loading...