Troubleshooting - A Guide to MATLAB for Beginners and Experienced Users - page 223

Here the vertical bar highlights the place where MATLAB believes the error
is located. In this case, the actual error is earlier in the input line.

Spelling Error

Using uppercase instead of lowercase letters in MATLAB commands, or
misspelling the command.

CAUSE:

SOLUTION: Fix the spelling.

Forexample,theUNIXversionof MATLABdoesnotrecognize Fzero or FZERO
(in spite of the convention that the help lines in MATLAB's M-files always
refer to capitalized function names); the correct command is fzero .

EXAMPLE:

>> Fzero(inline('xˆ2 - 3'), 1)
??? Undefined function or variable , Fzero , .
>> FZERO(inline('xˆ2 - 3'), 1)
??? Undefined function or variable , FZERO , .
>> text = help('fzero'); text(1:38)

ans =
FZERO Scalar nonlinear zero finding.
>> fzero(inline('xˆ2 - 3'), 1)

ans =

1.7321

Error Messages When Plotting

There are several possible explanations, but usually the problem is the wrong
type of input for the plotting command chosen.

CAUSE:

SOLUTION: Carefully follow the examples in the help lines of the plotting command,
and pay attention to the error messages.

EXAMPLE:

>> [X,Y] = meshgrid(-1:.1:1, -1:.1:1);
>> mesh(X, Y, sqrt(1 - X.ˆ2 - Y.ˆ2))
??? Error using ==> surface
X, Y, Z, and C cannot be complex.