From dda63dda3a0d50b5c6445f1762a1ed3b786ea467 Mon Sep 17 00:00:00 2001
From: Stephane Del Pino <stephane.delpino44@gmail.com>
Date: Tue, 6 Aug 2019 18:19:49 +0200
Subject: [PATCH] Add tests for non standard cases
---
tests/test_PCG.cpp | 59 ++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 59 insertions(+)
diff --git a/tests/test_PCG.cpp b/tests/test_PCG.cpp
index 11636132c..97bbe1ce2 100644
--- a/tests/test_PCG.cpp
+++ b/tests/test_PCG.cpp
@@ -47,4 +47,63 @@ TEST_CASE("PCG", "[algebra]")
Vector error = x - x_exact;
REQUIRE(std::sqrt((error, error)) < 1E-10 * std::sqrt((x, x)));
}
+
+ SECTION("singular matrix with RHS in its image")
+ {
+ SparseMatrixDescriptor<double, uint8_t> S{5};
+
+ CRSMatrix<double, uint8_t> A{S};
+
+ Vector<double> b{5};
+ b = 0;
+
+ Vector<double> x{5};
+ x = 0;
+
+ PCG{b, A, A, x, 10, 1e-12};
+ REQUIRE(std::sqrt((x, x)) == 0);
+ }
+
+ SECTION("no preconditionner non-converged")
+ {
+ SparseMatrixDescriptor S{5};
+ S(0, 0) = 2;
+ S(0, 1) = -1;
+
+ S(1, 0) = -1;
+ S(1, 1) = 2;
+ S(1, 2) = -1;
+
+ S(2, 1) = -1;
+ S(2, 2) = 2;
+ S(2, 3) = -1;
+
+ S(3, 2) = -1;
+ S(3, 3) = 2;
+ S(3, 4) = -1;
+
+ S(4, 3) = -1;
+ S(4, 4) = 2;
+
+ CRSMatrix A{S};
+
+ Vector<const double> x_exact = [] {
+ Vector<double> y{5};
+ y[0] = 1;
+ y[1] = 3;
+ y[2] = 2;
+ y[3] = 4;
+ y[4] = 5;
+ return y;
+ }();
+
+ Vector<double> b = A * x_exact;
+
+ Vector<double> x{5};
+ x = 0;
+
+ PCG{b, A, A, x, 1, 1e-12};
+ Vector error = x - x_exact;
+ REQUIRE(std::sqrt((error, error)) > 1E-10 * std::sqrt((x, x)));
+ }
}
--
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