For performance reasons, MATLAB® caches toolbox folder information across sessions. The caching features are mostly transparent to you. However, if MATLAB does not see the latest versions of your MATLAB code files or if you receive warnings about the toolbox path cache, then you might need to update the cache.
Upon startup, MATLAB gets information from a cache file to build the toolbox folder cache. Because of the cache file, startup is faster, especially if you run MATLAB from a network server or if you have many toolbox folders. When you end a session, MATLAB updates the cache file.
MATLAB does not use the cache file at startup if you clear the Enable toolbox path cache check box in General Preferences. Instead, it creates the cache by reading from the operating system folders, which is slower than using the cache file.
MATLAB caches (essentially, stores in a known files list)
the names and locations of files in
These folders are for files provided with MathWorks® products
that should not change except for product installations and updates.
Caching those folders provides better performance during a session
because MATLAB does not actively monitor those folders.
We strongly recommend that you save any MATLAB code files
you create and any files provided by MathWorks that
you edit in a folder that is not in the
tree. If you keep your files in
then they might be overwritten when you install a new version of MATLAB.
When you add files to
the cache and the cache file need to be updated. MATLAB updates
the cache and cache file automatically when you install toolboxes
or toolbox updates using the installer for MATLAB. MATLAB also
updates the cache and cache file automatically when you use MATLAB tools,
such as when you save files from the MATLAB Editor to
When you add or remove files in
by some other means, MATLAB might not recognize those changes.
For example, when you:
Save new files in
using an external editor
Use operating system features and commands to add
or remove files in
MATLAB displays this message:
Undefined function or variable
Update the cache so MATLAB recognizes the changes you made
To update the cache and the cache file,
On the Home tab, in the Environment section, click Preferences. Select MATLAB > General.
The General Preferences pane is displayed.
Click Update Toolbox Path Cache and click OK.
To update the cache, use
To also update the cache file, use
For more information, see
To display information about startup time when you start MATLAB, select the Enable toolbox path cache diagnostics check box in General Preferences.