Category: Matlab obscure functions

• Obscure Matlab features #4 – Writing help

  Keeping code undocumented now might save you a few minutes, but it will undoubtedly cause you pain and misery when you do revisions 6 months from now. As you surely know, Matlab’s built-in help function parses comments immediately following the function byline and outputs these comments in the command window. It has a couple of…

  October 13, 2011

• Obscure Matlab features #3: progress reports with publish

  Neurophysiology experiments can generate tons of data. In the initial stages of a project, you can easily become overwhelmed with the results of preliminary analyses. It’s a good idea to collect together the results of these analyses into a single document. This can make it easier to peruse the results with others in your lab,…

  September 4, 2011

• The joy of object-oriented programming in Matlab

  Matlab has had support for full object oriented programming (OOP) since 2008a. Those with an OOP background (say, in Java, C# or Python) will find Matlab’s OOP features to be fairly complete. These include: Pass-by-reference semantics via subclassing the handle class Instance methods and static methods Full selection of access control for methods, properties (public,…

  August 21, 2011

• Coarse-grained parallelism in Matlab with parfor

  Previously, I discussed how you can take advantage of multiple cores in C. In day-to-day research, however, it’s more common to work with high-level languages like Matlab and Python. Although Matlab has been multithreaded for several years now, it’s not very good at maximally using all the cores in a computer. You can verify this…

  June 29, 2011

• Obscure Matlab features #2: linear indexing, sub2ind, ind2sub

  Matlab supports 3 forms of indexing matrices. There is the familiar range indexing that selects a submatrix within a larger matrix: This is also called sub-indexing. There is also logical indexing: These two methods are fairly expressive, yet there are a certain number of operations which are awkward or impossible to perform with these. Let’s…

  June 12, 2011

• Obscure Matlab function #1: bsxfun

  Here’s a first in what might become a regular feature on xcorr: an exposition of some of Matlab’s obscure but quite useful functions. Today’s function: bsxfun. The Matlab documentation states that bsxfun’s function is to: Apply element-by-element binary operation to two arrays with singleton expansion enabled This is not a very helpful definition. What bsxfun(@op,A,B)…

  May 26, 2011