Doug’s MATLAB Video Tutorials

February 3rd, 2010

Win a MATLAB t-shirt for a ten question survey

It has been a while since the last survey of MATLAB video watchers. This is a good time to think about what can be done to make these videos more valuable.

Click here to take survey

One in twenty survey takers will win. The survey will be open for one week, the winners notified by e-mail. The results will be summarized in a future blog post.


In a completely unrelated note:

We have set up a Virtual Career Fair to recruit Graduate Students for The MathWorks. We will be hosting this event on February 4th, from 11 AM – 7PM. Our goal is to get over 2,000 graduate students to log into this event and learn more about us and working here! During the event, we will have live engineers and managers to chat with about the technical support opportunities.

Check it out here.

January 29th, 2010

Advanced: Speeding up an enumerated string search in a data mining application

This week, I am going to cover a technique that I used to speed up a data mining application that had a search through enumerated strings looking for all the matches. Using this technique of substituting numeric values for the strings, I was able to see a twenty fold speed increase.
Also, my colleague Scott thought that people interested in this video should check out categorical arrays in the statistics toolbox.

January 22nd, 2010

Advanced: making a 2d or 3d histogram to visualize data density

This short video makes a 2d histogram as an alternative to plotting data points and visually estimating where the most data is.

January 15th, 2010

Basics: Dialogapalooza- a look at many predefined dialogs

Very often MATLAB user will write in and we figure out that they are trying to reinvent a dialog that already exists. I quickly go through and show the most useful dialogs from this list.

January 8th, 2010

Basics: Refactoring a switchyard into a formula

This short video shows how a switchyard of if/elseif statements was converted to a simple formula. Testing of this refactoring was also done.

December 31st, 2009

Basics: Finding a subset of a matrix

Imagine you have a matrix, and you want to make a subset of that matrix that has only the rows that have a 2 in the first column. This is how you would do that.

December 17th, 2009

Advanced: Loading, filtering and displaying geographic data with the Mapping Toolbox.

This short video uses the Mapping Toolbox to load in the state boundaries in a given area and display them on a special map axis. Random points are also generated and filtered based on their location.

December 11th, 2009

Advanced: Making a sweeping slice through volume of data.

A MATLAB user recently asked how we could make a visualization similar to this one.

I was a little surprised that we were able to do the visualization, with interactivity in less that 15 lines of code.

%%
d = flow; d = shiftdim(d,2);
x = 25;
y = 26;
z = 21.59561;
v =  3.22068;

h = slice(d,x,y,z)
d(:,:,z:end) = nan;
isosurface(d,-v)

set(h,'edgeColor','none')
axis equal
zlim([0 size(d,3)])
colormap spring

This video makes use of cell mode to get the interactivity. You can see how something like this could be done with a GUI to get the interactivity that you might want.

If you like this kind of thing, Slice-o-matic, will be good for you.

December 7th, 2009

Basics: Volume visualization: 9/9 Unifying example

This short video is the final of a series of nine that talks about volume visualization. Patrick gave this talk internally to help technical support engineers understand capabilities of MATLAB for volume visualization.

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.

November 30th, 2009

Basics: Volume visualization: 8/9 Displays and explains streamtubes and streamribbons

This short video is the eigth of a series of nine that talks about volume visualization. Patrick gave this talk internally to help technical support engineers understand capabilities of MATLAB for volume visualization.

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.


Doug Hull is a proud MathWorker who is on a mission to help you with MATLAB.

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These postings are the author's and don't necessarily represent the opinions of The MathWorks.