Add info message to slow sparse diagonalization

commit ba5ebec
Author: David Plankensteiner <david.plankensteiner@uibk.ac.at>
Date:   Mon Jul 9 17:15:00 2018 +0200

    Suppress info in tests

commit e36f652
Author: David Plankensteiner <david.plankensteiner@uibk.ac.at>
Date:   Mon Jul 9 17:13:44 2018 +0200

    Print info when sparse diagonalization is used

src/spectralanalysis.jl

@@ -45,10 +45,14 @@ end
 """
 For sparse operators by default it only returns the 6 lowest eigenvalues.
 """
-function eigenstates(op::SparseOperator, n::Int=6; warning=true, kwargs...)
+function eigenstates(op::SparseOperator, n::Int=6; warning::Bool=true,
+        info::Bool=true, kwargs...)
     b = basis(op)
     # TODO: Change to sparese-Hermitian specific algorithm if more efficient
     ishermitian(op) || (warning && warn(nonhermitian_warning))
+    info && println("INFO: Defaulting to sparse diagonalization.
+        If storing the full operator is possible, it might be faster to do
+        eigenstates(full(op)). Set info=false to turn off this message.")
     D, V = eigs(op.data; which=:SR, nev=n, kwargs...)
     states = [Ket(b, V[:, k]) for k=1:length(D)]
     D, states
@@ -84,7 +88,7 @@ end
 """
 For sparse operators by default it only returns the 6 lowest eigenvalues.
 """
-eigenenergies(op::SparseOperator, n::Int=6; warning=true) = eigenstates(op, n; warning=warning)[1]
+eigenenergies(op::SparseOperator, n::Int=6; kwargs...) = eigenstates(op, n; kwargs...)[1]
 
 
 arithmetic_unary_error = operators.arithmetic_unary_error

test/test_spectralanalysis.jl

@@ -25,15 +25,15 @@ d = [-3, -2.6, -0.1, 0.0, 0.6]
 D = DenseOperator(b, diagm(d))
 Dsp = sparse(D)
 @test eigenenergies(D) ≈ d
-@test eigenenergies(Dsp, 3) ≈ d[1:3]
+@test eigenenergies(Dsp, 3, info=false) ≈ d[1:3]
 
 R = U*D*dagger(U)
 Rsp = sparse(R)
 @test eigenenergies((R+dagger(R))/2) ≈ d
-@test eigenenergies((Rsp+dagger(Rsp))/2, 3) ≈ d[1:3]
+@test eigenenergies((Rsp+dagger(Rsp))/2, 3; info=false) ≈ d[1:3]
 
 E, states = eigenstates((R+dagger(R))/2, 3)
-Esp, states_sp = eigenstates((Rsp+dagger(Rsp))/2, 3)
+Esp, states_sp = eigenstates((Rsp+dagger(Rsp))/2, 3, info=false)
 for i=1:3
     @test E[i] ≈ d[i]
     @test Esp[i] ≈ d[i]
@@ -53,15 +53,15 @@ d = [-3+0.2im, -2.6-0.1im, -0.1+0.5im, 0.0, 0.6+0.3im]
 D = DenseOperator(b, diagm(d))
 Dsp = sparse(D)
 @test eigenenergies(D; warning=false) ≈ d
-@test eigenenergies(Dsp, 3; warning=false) ≈ d[1:3]
+@test eigenenergies(Dsp, 3; warning=false, info=false) ≈ d[1:3]
 
 R = U*D*dagger(U)
 Rsp = sparse(R)
 @test eigenenergies(R; warning=false) ≈ d
-@test eigenenergies(Rsp, 3; warning=false) ≈ d[1:3]
+@test eigenenergies(Rsp, 3; warning=false, info=false) ≈ d[1:3]
 
 E, states = eigenstates(R, 3; warning=false)
-Esp, states_sp = eigenstates(Rsp, 3; warning=false)
+Esp, states_sp = eigenstates(Rsp, 3; warning=false, info=false)
 for i=1:3
     @test E[i] ≈ d[i]
     @test Esp[i] ≈ d[i]