Store explicit H matrix in the memory and solve

mat_eig.jl

@@ -0,0 +1,42 @@
+include("CPU.jl")
+
+T=Float32
+
+function V_test(r2)
+    return -4 * exp(-r2 / 4)
+end
+
+d = 1
+n = 3
+N = 8
+L::T = 16
+n_imag = 0
+μ::T = 0.5
+
+H = HOperator{T}(V_test, d, n, N, L, μ, n_imag)
+dim = N ^ (d * (n - 1))
+H_mat = zeros(Complex{T}, dim, dim)
+iter = CartesianIndices(vectorDims(H))
+
+open("temp/mat_dump.csv", "w") do f
+    # this can be heavily optimized by getting rid of 'bi' vector
+    for i in 1 : dim
+        bi = zeros(Complex{T}, vectorDims(H)...)
+        bi[iter[i]] = 1
+
+        for j in 1 : dim
+            bj = zeros(Complex{T}, vectorDims(H)...)
+            bj[iter[j]] = 1
+
+            Hbj = similar(bj)
+            Hbj = mul!(Hbj, H, bj)
+
+            H_mat[i, j] = dot(bi, Hbj)
+        end
+    end
+end
+
+evals, _ = eigen(H_mat)
+evals = real.(evals)
+
+print(evals)