Problem Plotting 4D data
2 次查看(过去 30 天)
显示 更早的评论
Hello everyone,
I have a dataset that is result of a 3D Scanner and it's in the format (x,y,z,value) for each point. The value of each point represents the strength of signal received by the antennas. The data is scanned in regular grid, but the values of the points with no signal received from are zero or very small.
Right now I am representing these points with "*" as follows:
for k=1:91
for j=1:101
for i=1:101
if 50<dbstolt(i,j,k)
plot3(i,j,k,'-r*');hold on
end
end
end
end
My original dataset is called dbstolt, I attached a photo for better understanding. http://tinypic.com/r/sawaxt/7
Now I would like to connect these points and make a 3D Surface from them, but I don't know how. Maybe using the function patch? but how do I determine the relation between the points?
Thanks in advance
2 个评论
采纳的回答
Andrew Newell
2011-4-13
You might be able to do it using isosurface with isovalue=50. You'll need to create x,y,z matrices using meshgrid.
6 个评论
Andrew Newell
2011-4-14
As well as Sean de's suggestion, you could try playing with lighting and colormap to improve your result.
更多回答(2 个)
Sean de Wolski
2011-4-14
The problem you're seeing is that the area of the edges is significant compared to the area of the faces. You could try either lowering the edgealpha or setting the edgecolor to none:
patch(fv,'edgecolor','none');%no edges
patch(fv,'edgealpha',0.2); %20% transparency in the edges.
2 个评论
Sean de Wolski
2011-4-14
It uses a marching cubesesque approach. Marching cubes as an algorithm was proprietary until 2006ish so Mathworks developed something similar for the isosurface function. I don't if they've since changed it and I don't know the details about its mechanisms. Steve Eddins would be the one to ask about that. See his blog here:
http://blogs.mathworks.com/steve/
As far as the colors. If you want the edges to show but not be black, you could set them to a slightly darker shade of the facecolor so they're still noticeable but don't interfere as much.
Ps. I'm also interested in the workings of the isosurface function, but I haven't delved into it.
Saeed68gm
2011-5-18
3 个评论
Asadullah
2012-7-17
Hey Saeed,
If you are interested to apply marching cubes algorithm to your data set then pls visit http://www.mathworks.com/matlabcentral/fileexchange/32506-marching-cubes
Sagar
2015-3-9
I am having a similar issue, I have similar scanner data and all I want is to show all the values in 3d space using the isosurface. How can I do? If I don't specify ISO value what exactly does it give? Do I need to use other 3d plot functions? Please suggest what is the best way to plot my x,y,z,value data in 3d space in a nice way. Thanks, -Sagar
-Sagar
另请参阅
产品
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!