MATLAB Function Reference

verLessThan - Compare toolbox version to specified version string

Syntax

verLessThan(toolbox, version)

Description

verLessThan(toolbox, version) returns logical 1 (true) if the version of the toolbox specified by the string toolbox is older than the version specified by the string version, and logical 0 (false) otherwise. Use this function when you want to write code that can run across multiple versions of the MATLAB^® software.

The toolbox argument is a string enclosed within single quotation marks that contains the name of a MATLAB toolbox directory. The version argument is a string enclosed within single quotation marks that contains the version to compare against. This argument must be in the form major[.minor[.revision]], such as 7, 7.1, or 7.0.1. If toolbox does not exist, MATLAB generates an error.

To specify toolbox, find the directory that holds the Contents.m file for the desired toolbox and use that directory name. To see a list of all toolbox directory names, enter the following command at the MATLAB prompt:

dir([matlabroot '/toolbox'])

Remarks

The verLessThan function is available with MATLAB Version 7.4. If you are running a version of MATLAB earlier than 7.4, you can download the verLessThan M-file from the following MathWorks Technical Support solution. You must be running MATLAB Version 6.0 or higher to use this M-file:

http://www.mathworks.com/support/solutions/data/1-38LI61.html?solution=1-38LI61

Examples

These examples illustrate the proper usage of the verLessThan function.

Example 1 – Checking For the Minimum Required Version

if verLessThan('simulink', '4.0')
    error('Simulink 4.0 or higher is required.');
end

Example 2 – Choosing Which Code to Run

if verLessThan('matlab', '7.0.1')
% -- Put code to run under MATLAB 7.0.0 and earlier here --
else
% -- Put code to run under MATLAB 7.0.1 and later here --
end

Example 3 – Looking Up the Directory Name

Find the name of the Data Acquisition Toolbox™ directory:

dir([matlabroot '/toolbox/d*'])

   daq        database   des      distcomp   dotnetbuilder
   dastudio   datafeed   dials    dml        dspblks

Use the toolbox directory name, daq, to compare the Data Acquisition version that MATLAB is currently running against version number 3:

verLessThan('daq', '3')
ans =
     1