public static void Mmul_ata(SMat3 mout, Mat3 a)
{
mout.SetSymmetric(a.m00 * a.m00 + a.m10 * a.m10 + a.m20 * a.m20,
a.m00 * a.m01 + a.m10 * a.m11 + a.m20 * a.m21,
a.m00 * a.m02 + a.m10 * a.m12 + a.m20 * a.m22,
a.m01 * a.m01 + a.m11 * a.m11 + a.m21 * a.m21,
a.m01 * a.m02 + a.m11 * a.m12 + a.m21 * a.m22,
a.m02 * a.m02 + a.m12 * a.m12 + a.m22 * a.m22);
}
public static void Rot12(SMat3 m, float c, float s)
{
float [] cs = Svd.CalcSymmetricGivensCoefficients(m.m11, m.m12, m.m22, c, s);
float cc = cs[0] * cs[0];
float ss = cs[1] * cs[1];
float mix = 2 * c * s * m.m12;
m.SetSymmetric(m.m00, c * m.m01 - s * m.m02, s * m.m01 + c * m.m02,
cc * m.m11 - mix + ss * m.m22, 0, ss * m.m11 + mix + cc * m.m22);
}
public static void Rot01(SMat3 m, float c, float s)
{
float [] cs = Svd.CalcSymmetricGivensCoefficients(m.m00, m.m01, m.m11, c, s);
float cc = cs[0] * cs[0];
float ss = cs[1] * cs[1];
float mix = 2 * c * s * m.m01;
m.SetSymmetric(cc * m.m00 - mix + ss * m.m11, 0, c * m.m02 - s * m.m12,
ss * m.m00 + mix + cc * m.m11, s * m.m02 + c * m.m12, m.m22);
}
public static void GetSymmetricSvd(SMat3 a, SMat3 vtav, Mat3 v, float tol, int max_sweeps)
{
vtav.SetSymmetric(a);
v.Set(1, 0, 0, 0, 1, 0, 0, 0, 1);
float delta = tol * MatUtils.Fnorm(vtav);
for (int i = 0; i < max_sweeps && MatUtils.Off(vtav) > delta; ++i)
{
Rotate01(vtav, v);
Rotate02(vtav, v);
Rotate12(vtav, v);
}
}
