ERROR: type Tuple has no field values

New to Julia
1

I’m trying to simulate a projection measurement of quantum system, here is the code involving error

‘’’

Calculate eigenvalues and eigenvectors

eigen = eigs(X1.data)
eigenvalues = eigen.values
eigenvectors = eigen.vectors
‘’’

X1 is a four-mode operator, the error happens at the “eigenvalues=eigen.values”, and here is the error message:

ERROR: type Tuple has no field values
Stacktrace:
[1] getproperty(x::Tuple{Vector{ComplexF64}, Matrix{ComplexF64}, Int64, Int64, Int64, Vector{ComplexF64}}, f::Symbol)

I don’t understand what caused this error and how could I fix this?

2

Which package is eigs coming from and is its docstring saying that you should extract eigenvalues with .values? My best guess is that you’re supposed to do

eigenvalues, eigenvectors = eigs(X1.data)
2 Likes
3

Oh! It works for now! Thank you so much! eigs is from Arpack, I was using LinearAlgebra, but it doesn’t allow me to, I guess that’s because the structure of my operator, and the error message suggest me to use eigs from Arpack so I use it.