MATLAB: Does M-Lint show me a message “END or Colon is apparently used to index an non-array” in MATLAB 7.5 (R2007b)

MATLABmlint

In the attached example M-Lint displays a message in line 38 for the colon:

ann = an(r,:);

As "an" is not defined before, but will be written out of the Simulink model to the current workspace "an" will be known and the program will run as expected.

If I comment out the function line and execute the code as a script this message does not occur.

Best Answer

M-Lint shows the message because in its static analysis, it is unable to determine that "an" is a variable. It assumes it is a function and therefore shows that warning. It does not show an error for the statement,

ann = an(r,1:k);

because this is a valid method of accessing a function (passing the vector 1:k as input), and therefore fits in M-Lints assumption about "an". However,

ann = an(r,:);

is not a valid function call and results in an M-Lint error.

This behavior is a little confusing and has been improved in MATLAB version 7.7 (R2008b) and above.

Related Solutions

MATLAB: Do I receive an error when I use the colon operator (:) in the Embedded MATLAB Function block as described in the documentation for Simulink 6.1 (R14SP1)

This bug has been fixed in Release 14 Service Pack 2 (R14SP2). For previous releases, please read below for any possible workarounds:

We have verified that there is an error in the "Limitations on Indexing Operations" section of the documentation associated with the Embedded MATLAB Function block in Simulink 6.1 (R14SP1).

The correct version of the documentation should read as follows:

 * M(i,j) where i and j change in a loop
 Embedded MATLAB never dynamically allocates memory for the size of the expressions that change as the program executes. The workaround is to use for loops as shown in the following example:
 for i=1:10
     for j = i:10
         M(i,j) = 2 * M(i,j);
     end
 end

MATLAB: How to permanently disable a specific warning that M-Lint generates

The ability to set system-wide preferences for M-Lint warnings and errors was added in MATLAB 7.3 (R2006b). These may be set in the general preferences by selecting from the MATLAB desktop 'File->Preferences...' and clicking on the 'M-Lint' node.

For previous versions, you may disable M-Lint warnings and errors on a specific line of MATLAB code. To do this, add the "%#ok" token to the end of the line with the warning to force M-Lint to skip checking the line of code.

Best Answer

Related Solutions

MATLAB: Do I receive an error when I use the colon operator (:) in the Embedded MATLAB Function block as described in the documentation for Simulink 6.1 (R14SP1)

MATLAB: How to permanently disable a specific warning that M-Lint generates

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