Why am I unable to visualize umlaut characters "ä ö ü" in uicontrol objects when I use a German keyboard on a Linux machine?

When I use a German keyboard, umlauts are incorrectly represented in UIcontrols such as listboxes. This only occurs in MATLAB versions 7.0 and later (R14 ). I do not have the same issue using MATLAB R13.

Answer 1

[MathWorks Support Team]

This issue can be resolved by setting the environment variable LANG in Linux, which correctly uses the ASCII indications of each keyboard. Enter the following instructions in a Linux console:

 setenv LANG de_DE.UTF-8

 -OR-

 setenv LANG de_DE

Depending on the type of Shell that you use, you might need to use the command export instead, as follows:

 export LANG="de_DE.UTF-8"

 -OR-

 export LANG="de_DE"

This issue does not appear prior to MATLAB 7.0 because previous versions of MATLAB did not perform character checking. Now that character checking has been introduced, characters not in the current ASCII character set may not appear in uicontrol object strings.

The first 128 codes (0 to 127) of the ASCII table have a fixed character mapped to it. The extended ASCII codes (128 to 255) are mapped according to the language setting. This is why Linux requires this setting to be set in order to be able to map the characters to what you would expect.