work around stupid msvc error when constructing at compile time an expression
that involves a division by zero, even if the numeric type has floating point
diff --git a/Eigen/src/SVD/JacobiSVD.h b/Eigen/src/SVD/JacobiSVD.h
index f3b0ccc..44880dc 100644
--- a/Eigen/src/SVD/JacobiSVD.h
+++ b/Eigen/src/SVD/JacobiSVD.h
@@ -239,6 +239,9 @@
* \a p is the greater dimension, meaning that it is still of the same order of complexity as the faster bidiagonalizing R-SVD algorithms.
* In particular, like any R-SVD, it takes advantage of non-squareness in that its complexity is only linear in the greater dimension.
*
+ * If the input matrix has inf or nan coefficients, the result of the computation is undefined, but the computation is guaranteed to
+ * terminate in finite (and reasonable) time.
+ *
* The possible values for QRPreconditioner are:
* \li ColPivHouseholderQRPreconditioner is the default. In practice it's very safe. It uses column-pivoting QR.
* \li FullPivHouseholderQRPreconditioner, is the safest and slowest. It uses full-pivoting QR.
diff --git a/test/jacobisvd.cpp b/test/jacobisvd.cpp
index 212f7f1..79a05b3 100644
--- a/test/jacobisvd.cpp
+++ b/test/jacobisvd.cpp
@@ -209,18 +209,30 @@
VERIFY_IS_APPROX(m.jacobiSvd(ComputeFullU|ComputeFullV).solve(m), m);
}
+// work around stupid msvc error when constructing at compile time an expression that involves
+// a division by zero, even if the numeric type has floating point
+template<typename Scalar>
+EIGEN_DONT_INLINE Scalar zero() { return Scalar(0); }
+
template<typename MatrixType>
void jacobisvd_inf_nan()
{
+ // all this function does is verify we don't iterate infinitely on nan/inf values
+
JacobiSVD<MatrixType> svd;
typedef typename MatrixType::Scalar Scalar;
- Scalar some_inf = Scalar(1) / Scalar(0);
+ Scalar some_inf = Scalar(1) / zero<Scalar>();
+ VERIFY((some_inf - some_inf) != (some_inf - some_inf));
svd.compute(MatrixType::Constant(10,10,some_inf), ComputeFullU | ComputeFullV);
- Scalar some_nan = Scalar(0) / Scalar(0);
+
+ Scalar some_nan = zero<Scalar>() / zero<Scalar>();
+ VERIFY(some_nan != some_nan);
svd.compute(MatrixType::Constant(10,10,some_nan), ComputeFullU | ComputeFullV);
+
MatrixType m = MatrixType::Zero(10,10);
m(ei_random<int>(0,9), ei_random<int>(0,9)) = some_inf;
svd.compute(m, ComputeFullU | ComputeFullV);
+
m = MatrixType::Zero(10,10);
m(ei_random<int>(0,9), ei_random<int>(0,9)) = some_nan;
svd.compute(m, ComputeFullU | ComputeFullV);
