missing hermitianpart(x::Number) = real(x)

[stevengj]

It seems like this should be defined for numbers, since hermitianpart is just a generalization of the real part (indeed, in some literature it is called the "operator real part"):

julia> hermitianpart(3+4im)
ERROR: MethodError: no method matching hermitianpart(::Complex{Int64})

Should be easy for someone to add a hermitianpart(x::Number) = real(x), update the docstring, and add a test.

(This came up in #1437 for generic code on Hermitian(::Diagonal). Note that the original PR for hermitianpart included a ::Number method, but it was removed by @dkarrasch at the time because the application was unclear, but with the option of adding it back: JuliaLang/julia#31836 (comment))

[GianmarcoCuppari]

Hi @stevengj ! I've worked on implementing the requested hermitianpart method for numbers. Here's what I've done:

• Added the method: hermitianpart(x::Number) = real(x) in src/symmetric.jl
• Updated documentation: Added a note in the docstring explaining that for numbers, hermitianpart returns the real part
• Added tests: Included test cases to verify the behavior with complex numbers

This should resolve the MethodError you encountered with hermitianpart(3+4im) and support the generic code usage in #1437.
I'm new to open source contributions and wanted to make sure I'm on the right track before submitting the PR. Could you confirm this covers everything needed? I'd appreciate any feedback to ensure I'm following the project's conventions correctly.
Thanks for your patience as I learn the contribution process!

[dkarrasch]

Hi @GianmarcoCuppari, thanks for taking up the initiative, that's much appreciated. Please submit a pull request with what you have. Then others can review the changes, give feedback or suggest concrete changes. A pull request doesn't have to be "perfect" right from the start, and working on the details is usually insightful and rewarding, at least that's my personal experience.

[GianmarcoCuppari]

Thank you for the kind words and encouragement!
I’ve just submitted the pull request.
Looking forward to the review and happy to make any adjustments if needed.