[algorithms.cholesky] also throw on NaN input

.gitsuper

@@ -18,7 +18,7 @@ status = 1a3bcab04b011a5d6e44f9983cae6ff89fa695e8 bin (heads/master)
 	 b8cf8efc32e46511990b691afee55da3b7af15c8 dune-xt-data (heads/master)
 	 0c9df39934e23b950f357c912b4c800b86de683f dune-xt-functions (heads/dailywork_tleibner)
 	 dd30fcd7d4485eb2a8158d5ddf01333f58502c40 dune-xt-grid (heads/master)
-	+9762d4f7bfcaa3424fc4aeaf362fa2b7710898ea dune-xt-la (heads/dailywork-tleibner)
+	+8c660bdad165a189b44c3f6e92e73e07cff1d774 dune-xt-la (heads/dailywork-tleibner)
 	 09d0378f616b94d68bcdd9fc6114813181849ec0 scripts (heads/master)
 commit = 02dfba6e3d4fa4659a18ce0f63b5956e1e557f16
 
@@ -115,7 +115,7 @@ commit = dd30fcd7d4485eb2a8158d5ddf01333f58502c40
 [submodule.dune-xt-la]
 remote = git@github.com:dune-community/dune-xt-la.git
 status = 2424627f0ad5de7e4aaa5e7f48bc2a02414d95a1 .vcsetup (heads/master)
-commit = 9762d4f7bfcaa3424fc4aeaf362fa2b7710898ea
+commit = 8c660bdad165a189b44c3f6e92e73e07cff1d774
 
 [submodule.scripts]
 remote = https://github.com/wwu-numerik/scripts.git

dune/xt/la/algorithms/cholesky.hh

@@ -37,7 +37,7 @@ void tridiagonal_ldlt(FirstVectorType& diag, SecondVectorType& subdiag)
   typedef Common::VectorAbstraction<SecondVectorType> V2;
   V1::set_entry(diag, 0, V1::get_entry(diag, 0));
   for (size_t ii = 0; ii < diag.size() - 1; ++ii) {
-    if (V1::get_entry(diag, ii) <= 0)
+    if (!(V1::get_entry(diag, ii) > 0)) // use !(.. > 0) instead of (.. <= 0) to also throw on NaNs
       DUNE_THROW(MathError, "LDL^T factorization failed!");
     V2::set_entry(subdiag, ii, V2::get_entry(subdiag, ii) / V1::get_entry(diag, ii));
     V1::set_entry(
@@ -104,7 +104,7 @@ void cholesky_rowwise(MatrixType& A)
     auto L_ii = M::get_entry(A, ii, ii);
     for (size_t kk = 0; kk < ii; ++kk)
       L_ii -= std::pow(M::get_entry(L, ii, kk), 2);
-    if (L_ii <= 0)
+    if (!(L_ii > 0)) // use !(.. > 0) instead of (.. <= 0) to also throw on NaNs
       DUNE_THROW(MathError, "Cholesky factorization failed!");
     M::set_entry(L, ii, ii, std::sqrt(L_ii));
   } // ii
@@ -120,7 +120,7 @@ void cholesky_colwise(MatrixType& A)
     auto L_jj = M::get_entry(A, jj, jj);
     for (size_t kk = 0; kk < jj; ++kk)
       L_jj -= std::pow(M::get_entry(L, jj, kk), 2);
-    if (L_jj <= 0)
+    if (!(L_jj > 0)) // use !(.. > 0) instead of (.. <= 0) to also throw on NaNs
       DUNE_THROW(MathError, "Cholesky factorization failed!");
     L_jj = std::sqrt(L_jj);
     M::set_entry(L, jj, jj, L_jj);
@@ -167,7 +167,7 @@ cholesky_csr(MatrixType& A)
     auto kk = row_pointers[ii];
     while (kk < row_pointers[ii + 1] && size_t(column_indices[kk]) < ii)
       L_ii -= std::pow(entries[kk++], 2);
-    if (L_ii <= 0)
+    if (!(L_ii > 0)) // use !(.. > 0) instead of (.. <= 0) to also throw on NaNs
       DUNE_THROW(MathError, "Cholesky factorization failed!");
     M::set_entry(L, ii, ii, std::sqrt(L_ii));
   } // ii