Not enough input arguments.

------ I have a problem with this code. The code run for Matlab2011 and I have 2014a. It was typed from Matlab book, so the code is right... and This is de code:

function RHz=HRz(theta)
dato=whos('theta');
if strcmp(dato.class','sym')
    RHz=[cos(theta), -sin(theta), 0,0;
        sin(theta), cos(theta), 0,0;
        0,0,1,0;
        0,0,0,1];
else digits(3);
    RHz=round([vpa(cos(theta),3), vpa(-sin(theta),3),0,0;
        vpa(sin(theta),3), vpa(cos(theta),3),0,0;
        0,0,1,0;
        0,0,0,1]);
end

---------------------Error is:

Error using strcmp
Not enough input arguments.

Error in HRz (line 3)
if strcmp(dato.class,'sym')

[Geoff Hayes]

Gizeh - perhaps you have another function named strcmp which is conflicting with the expected MATLAB one. In the command line, type

which strcmp -all

to see where this function has been defined.

[Guillaume]

The line of code in the error message does not match exactly the line of code in the given function. The function has an extra ' after dato.class that the error message doesn't show. Which of the two (if any) shows the actual code?

Note that there is no need to go the roundabout way to get the class of theta, the following would be simpler:

function RHz=HRz(theta)
if strcmp(class(theta), 'sym')
    %... rest of the code as it is

It won't result the problem with strcmp which should not raise the error you give unless you have indeed shadowed it with you own version as per Geoff's comment.

[Walter Roberson]

isa(theta, 'sym')

[madhan ravi]

+1 sir Walter

Answer 1

[Cris LaPierre]

The error message suggest dato.class is empty. The trailing ' is not going to help the comparison, but when dato.class has a value, that alone doesn't generate an error message.

What are you passing into the function as theta? The only way I get this error message with this setup is if theta does not exist.