Doug's MATLAB Video Tutorials

December 7th, 2009

I like his slow, clear, methodical presentation with great visualizations. It is the first time I have deeply understood some of the volume visualization techniques we have.

• 1 of 9 Definitions for scalar and vector fields.
• 2 of 9 Examples of scalar and vector fields (temperature in a room vs air currents)
• 3 of 9 Displays scatter3 and slice plots.
• 4 of 9 Displays contourslice and isosurface.
• 5 of 9 Making a 3-d plot ‘pretty’ with lighting, shading, interpolation, etc…
• 6 of 9 Displays quiver3 and coneplot
• 7 of 9 Displays and explains streamplot and streamslice
• 8 of 9 Displays and explains streamtubes and streamribbons
• 9 of 9 Unifying example

By Doug Hull

Doug first used MATLAB in 1994, could not figure it out until he got some help in 1995. He is now dedicated to making sure that no one else wastes a year of their life not knowing MATLAB like he did.

15:19 UTC | Posted in Format: Video, Level: Basic | Permalink | 8 Comments »

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8 Responses to “Basics: Volume visualization: 9/9 Unifying example”

1. Vick replied on December 17th, 2009 at 05:52 UTC :
   

   Hey Patrick and Doug, nice wrap-up work. is it possible to put a “wrap-up script” of all the examples (from video 1-9) so one can play with it — im too lazy to type ‘em up..

   Thanks

2. Patrick Kalita replied on December 17th, 2009 at 21:21 UTC :
   

   Hi Vick,

   I’m working on getting the scripts I used to generate the presentation’s images on the File Exchange. Stay tuned…

   -Patrick

3. Patrick Kalita replied on January 5th, 2010 at 15:02 UTC :
   

   The scripts are now available here:

   http://www.mathworks.com/matlabcentral/fileexchange/26263

4. Allen Gary replied on February 16th, 2010 at 17:48 UTC :
   

   Can the flux tubes by made semi-transparent, with transparency dependent on the length of the line of sight through the flux tube?

5. dhull replied on February 16th, 2010 at 19:45 UTC :
   

   Allen,

   You have the ability to set transparency (alpha) on HG objects. The trick is getting the handle to them. Different functions hand back handles at different levels of granularity. You can use whatever algorithm you want to set the different transparency values (constant, or dependent on a function like you mention) are possible.

   The more custom the design, the more you will be hunting around for handles and such though.

   Doug

6. Adam Jones replied on July 13th, 2011 at 11:10 UTC :
   

   Doug, that’s very true, I’ll try to set the different transparency values too.

7. TonoY replied on November 4th, 2012 at 19:48 UTC :
   

   Dear Mr. Doug,

   I saw your videos on – volume visualization as well as -surface plot on nonuniform data. Those were extremely helpful. However, I have a database as follows:

   x(:,1) = longitude
   y(:,2) = latitude
   z(:,3) = depth
   v(:,4) = toxic metal concentration

   The data is irregularly spaced, and as you can see, all data are vector data. From your video, scatter3(x(:),y(:),z(:),[], v(:)) — plots a nice 3D scatter plot with colored metal concentration. But when I want to get a slice out of it as– slice(x, y, z, v, [], [], 30) — it says ‘v’ has to be a 3D array. Since metal concentration is not a function of x, y, and z, it can’t be a 3D array. Moreover, I really don’t understand how ‘interpn’ work, actually I tried and failed. So my straight-forward questions to you:

   1. Is there any way to make v (metal conc.) = a volume of data or 3D array so that I can get a slice or isosurface out of it?
   2. If not, then how can I use the ‘interpn’ to get the ‘v’?

   Please find a small portion of my database here: http://www.mediafire.com/view/?4k2f80yu32yjy23. Thank you in advance for your time and effort to answer my questions.

8. Doug replied on November 19th, 2012 at 16:08 UTC :
   

   Tonyo: Try this one:

   http://blogs.mathworks.com/videos/2010/01/22/advanced-making-a-2d-or-3d-histogram-to-visualize-data-density/

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