Are some Greek characters not supported?

In R2017b, I tried to use \varphi in a legend and got the error message:

*Warning: Error updating Legend.

 Character vector must have valid interpreter syntax:
\varphi*

If I shorten it to \phi , it displays as expected. What's going on?

Answer 1

[Walter Roberson]

\varphi requires interpreter latex, and requires math mode (that is, enclosed in $)

text(1,1,'$\phi \varphi$', 'interpreter', 'latex')

[Paul McKenzie]

That works for the 'text' command, but not for a legend; it simply results in a legend that reads $\varphi$. Not the answer I was hoping for.

[Walter Roberson]

g = legend('$\varphi$'); g.Interpreter = 'latex';

[Paul McKenzie]

Where is it documented which LateX characters require math mode? this seems like a completely arbitrary & stupid limitation and a lazy implementation!

[Walter Roberson]

Take it up with Mathworks. I provided the work-around, and no amount of ranting at me will suddenly make the Mathworks implementation do something different than it does.

[Paul McKenzie]

Walter: Your second answer worked for legend. Thank you! My rant was not aimed at you.

[Walter Roberson]

https://tex.stackexchange.com/questions/82093/why-does-mathrm-varphi-work-but-text-varphi-does-not

[Paul McKenzie]

That URL seems to suggest that it's a TeX 'limitation' and not something that Mathworks can (easily) fix.

[Walter Roberson]

History: https://tex.stackexchange.com/questions/304534/what-does-the-var-prefix-stand-for-in-varphi-and-varepsilon-etc

If you look at the comprehensive list of LaTeX symbols http://tug.ctan.org/info/symbols/comprehensive/symbols-a4.pdf, you will find that \alpha and so on are table 184, well inside Section 3 describing Mathematics Mode