Decreasing threshold at which L-BFGS Hessian is updated.
- Decreasing threshold at which L-BFGS Hessian is updated from 1e-10
to 1e-14 results in a very significant improvement in NIST scores
(43 -> 53 for CUBIC).
- Adding comment in FindPolynomialRoots() explaining why behaviour
is correct.
Change-Id: If668e087e7a86d29659aa74e8528b192b604c841
diff --git a/internal/ceres/polynomial.cc b/internal/ceres/polynomial.cc
index feec884..e548da0 100644
--- a/internal/ceres/polynomial.cc
+++ b/internal/ceres/polynomial.cc
@@ -137,6 +137,9 @@
if (degree == 0) {
LOG(WARNING) << "Trying to extract roots from a constant "
<< "polynomial in FindPolynomialRoots";
+ // We return true with no roots, not false, as if the polynomial is constant
+ // it is correct that there are no roots. It is not the case that they were
+ // there, but that we have failed to extract them.
return true;
}
