2.4.3 Can you answer these questions?

2.4.3.1 What is the fastest way to get the lowest eigenvalue and corresponding eigenstate in Mathematica?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=235678

I tried to use the Arnoldi method to get the smallest eigenvalue and corresponding eigenstate for large matrix. However, Arnoldi did not give me the desired result:

asked by lol https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=40838 2 votes

2.4.3.2 How do I get built-in functions to use custom objects as if they were e.g. List?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=235391

(This is part 2 of my earlier question, Can I overload Part for specific heads (a la overloaded array subscripting)?, which was well-answered as asked.)

Overview: My goal is to create a custom object -...

asked by Josh Helzer https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=75893 3 votes

2.4.3.3 How to speed up this code (finding eigenvector with smallest eigenvalue)?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=235775

I have following code. The function TraceSystem is to take partial trace of matrix and I think this part is fine. The main code is below in dd and I think the main problem is in here for Eigenvector. ...

asked by lol https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=40838 1 vote