Improve further the accuracy of JacobiSVD wrt under/overflow while improving speed for small matrices (hypot is very slow).

This commit is contained in:
Gael Guennebaud
2014-09-10 23:11:58 +02:00
parent 2d90484450
commit 5e890d3ad7
2 changed files with 35 additions and 11 deletions

View File

@@ -354,11 +354,33 @@ void jacobisvd_underoverflow()
Matrix2d M;
M << -7.90884e-313, -4.94e-324,
0, 5.60844e-313;
JacobiSVD<Matrix2d> svd;
svd.compute(M,ComputeFullU|ComputeFullV);
jacobisvd_check_full(M,svd);
VectorXd value_set(9);
value_set << 0, 1, -1, 5.60844e-313, -5.60844e-313, 4.94e-324, -4.94e-324, -4.94e-223, 4.94e-223;
Array4i id(0,0,0,0);
int k = 0;
do
{
M << value_set(id(0)), value_set(id(1)), value_set(id(2)), value_set(id(3));
svd.compute(M,ComputeFullU|ComputeFullV);
jacobisvd_check_full(M,svd);
id(k)++;
if(id(k)>=value_set.size())
{
while(k<3 && id(k)>=value_set.size()) id(++k)++;
id.head(k).setZero();
k=0;
}
} while((id<int(value_set.size())).all());
#if defined __INTEL_COMPILER
#pragma warning pop
#endif
JacobiSVD<Matrix2d> svd;
svd.compute(M); // just check we don't loop indefinitely
// Check for overflow:
Matrix3d M3;
@@ -367,7 +389,8 @@ void jacobisvd_underoverflow()
-8.7190887618028355e+307, -7.3453213709232193e+307, -2.4367363684472105e+307;
JacobiSVD<Matrix3d> svd3;
svd3.compute(M3); // just check we don't loop indefinitely
svd3.compute(M3,ComputeFullU|ComputeFullV); // just check we don't loop indefinitely
jacobisvd_check_full(M3,svd3);
}
void jacobisvd_preallocate()