Stuart’s MATLAB Videos

Watch and Learn

This is machine translation

Translated by Microsoft
Mouseover text to see original. Click the button below to return to the English version of the page.

Using logical indexing to plot points meeting a specific criteria only.

Posted by Doug Hull,

If you have a vector of coordinate for a set of points, you might want to differentiate those points. To do that a concept called logical indexing will help you pull out a subset of those points easily. Here is a quick example (See the second video for more details)

 >> L = logical([0 1 0 1])
 
 L =
 
      0     1     0     1
 
 >> a = [1 2 3 4]
 
 a =
 
      1     2     3     4
 
 >> a(L)
 
 ans =
 
      2     4
 

The above video made practical use of logical indexing. The video below shows logical indexing in a more academic treatment.