//BestPlane returns a row vector that is normal to the plane that best contains the molecule
//if passed a nil Masser, it will simply set all masses to 1.
func BestPlane(coords *v3.Matrix, mol Masser) (*v3.Matrix, error) {
var err error
var Mmass []float64
cr, _ := coords.Dims()
if mol != nil {
Mmass, err = mol.Masses()
if err != nil {
return nil, errDecorate(err, "BestPlane")
}
if len(Mmass) != cr {
return nil, CError{fmt.Sprintf("Inconsistent coordinates(%d)/atoms(%d)", len(Mmass), cr), []string{"BestPlane"}}
}
}
moment, err := MomentTensor(coords, Mmass)
if err != nil {
return nil, errDecorate(err, "BestPlane")
}
evecs, _, err := v3.EigenWrap(moment, appzero)
if err != nil {
return nil, errDecorate(err, "BestPlane")
}
normal, err := BestPlaneP(evecs)
if err != nil {
return nil, errDecorate(err, "BestPlane")
}
//MomentTensor(, mass)
return normal, err
}
//A very basic analysis of the moment of inertia tensor.
func main() {
mol, err := chem.XYZFileRead("../sample.xyz")
if err != nil {
panic(err.Error())
}
mass, err := mol.Masses()
if err != nil {
mass = nil //MomentTensor will simply assign 1 to all masses
}
coords := mol.Coords[0]
moment, err := chem.MomentTensor(coords, mass)
if err != nil {
panic(err.Error())
}
eigvectors, eigvalues, err := v3.EigenWrap(moment, -1)
if err != nil {
panic(err.Error())
}
main := eigvectors.VecView(2) //The last is the widest.
fmt.Printf("Widest eigenvector: %v Corresponding eigenvalue: %4.1f\n", main, eigvalues[2])
}