Add nice error message to steadystate for sparse operators

qojulia · Jan 11, 2017 · ad4ac75 · ad4ac75
1 parent 660608d
commit ad4ac75
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Showing 2 changed files with 13 additions and 1 deletion.
diff --git a/src/steadystate.jl b/src/steadystate.jl
@@ -98,7 +98,15 @@ function eigenvector(L::DenseSuperOperator)
 end
 
 function eigenvector(L::SparseSuperOperator)
-    d, v, nconv, niter, nmult, resid = Base.eigs(L.data; nev=1, sigma=1e-30)
+    d, v, nconv, niter, nmult, resid = try
+      Base.eigs(L.data; nev=1, sigma=1e-30)
+    catch err
+      if isa(err, LinAlg.SingularException)
+        error("Base.LinAlg.eigs() algorithm failed; try using DenseOperators")
+      else
+        rethrow(err)
+      end
+    end
     data = reshape(v[:,1], length(L.basis_r[1]), length(L.basis_r[2]))
     op = DenseOperator(L.basis_r[1], L.basis_r[2], data)
     return op/trace(op)

diff --git a/test/test_steadystate.jl b/test/test_steadystate.jl
@@ -66,3 +66,7 @@ nss = expect(create(fockbasis)*destroy(fockbasis), ρss)
 ρss = steadystate.eigenvector(full(Hp), map(full, Jp))
 nss = expect(create(fockbasis)*destroy(fockbasis), ρss)
 @test n_an - real(nss) < 1e-3
+
+
+# Test error messages
+@test_throws ErrorException steadystate.eigenvector(sx, [sm])