'latex' is invalid for 'port_label' drawing command parameter 'Interpreter' in block '.....'

I created and masked a subsystem in MATLAB Simulink, I want to label one of the output port with Latex expression using the following command:

port_label('output',1,'\dot{\theta}(t)','Interpreter','latex')

But it gives me the following error message:

'latex' is invalid for 'port_label' drawing command parameter 'Interpreter' in block '.....'

How can I label an output or input of a subsystem using 'Interpreter'. More specifically, How can I use the latex symbol '\dot{}' which represent the first derivative of a variable?

[Walter Roberson]

Odd, the documentation https://www.mathworks.com/help/simulink/slref/port_label.html shows an example with 'interp', 'latex' and yet does not list 'interp' or 'interpreter' as a valid option.

Even more odd: I am having difficulty finding a port_label command . I am now searching through my installation.

I cannot see from the documentation how it would know which object is to be affected.

[N/A]

Thanks Mr. Walter Roberson for your response.

I have tried 'interp' instead of 'Interpreter', but both didn't work for me.

[Walter Roberson]

I found a number of places where port_label was used but no definition of it.

Hmmm, the reference I just found suggests that it is handled by set_param. Unfortunately that is a built-in so I cannot examine the source.