Problem allocating vector components

New to Julia
1

Hello, there!
I’m studying the spacing s between eigenvalues of 2\times2 matrices. My code is the following (some description lies in the comments):

using Distributions
using LinearAlgebra

d1 = Normal(0.0,1)
d2 = Normal(0.0,1/2)
N = 10 #size of the ensemble

for k in 1:N #loop that generates the N sets of eigenvalues
        
    for i in 1:2 #generating the random gaussian matrix
        for j in 1:2
            if i == j B[i,j] = rand(d1)
            end
        end
    end
    B[1,2] = B[2,1] = rand(d2)

    λ = eigvals(B) #calculating the eigenvalues
    s[k] = abs(λ[1] - λ[2]) #calculating the spacement between them
end

I’m trying to storage the information about the spacement of the N matrices at the ensemble in the vector s, wich may have N components, but I receive the following error when I try to run:

MethodError: no method matching setindex!(::Float64, ::Float64, ::Int64)

Someone knows what is wrong?

2

I can’t reproduce the error here. In your code s is not defined, but even if I define it, I do not get any error.

2 Likes
3

Yeah, this is strange. I restarted juno, recompiled and it worked. Thank tou very much! :smiley:

1 Like