Ejemplo n.º 1
0
// SpectralCompose recreates tensor m from its spectral decomposition
// m   -- 2nd order tensor in Mandel basis
// λ   -- eigenvalues
// n   -- eigenvectors [ncp][nvecs]
// tmp -- temporary matrix [3][3]
func SpectralCompose(m, λ []float64, n, tmp [][]float64) {
	for i := 0; i < 3; i++ {
		for j := 0; j < 3; j++ {
			tmp[i][j] = λ[0]*n[i][0]*n[j][0] + λ[1]*n[i][1]*n[j][1] + λ[2]*n[i][2]*n[j][2]
		}
	}
	tsr.Ten2Man(m, tmp)
}
Ejemplo n.º 2
0
// spectral_decomp computes the spectral decomposition of b := F*tr(F) tensor
func (o *Ogden) b_and_spectral_decomp(F [][]float64) (err error) {

	// determinant of F
	o.J, err = tsr.Inv(o.Fi, F)
	if err != nil {
		return
	}

	// left Cauchy-Green tensor
	tsr.LeftCauchyGreenDef(o.b, F)

	// eigenvalues and eigenprojectors
	tsr.Ten2Man(o.bm, o.b)
	err = tsr.M_EigenValsProjsNum(o.P, o.λ, o.bm)
	if err != nil {
		return
	}
	o.λ[0] = math.Sqrt(o.λ[0])
	o.λ[1] = math.Sqrt(o.λ[1])
	o.λ[2] = math.Sqrt(o.λ[2])
	return
}