lambda1 Function

public function lambda1(model, X, s, z0, zi, u, u_new, P)

Uses

- yaeos__math_linalg

lambda1

Calculation of the first restriction of a critical point

$\lambda_1(s) = \frac{d^2tpd}{ds^2} = 0$

Arguments

Type	Intent	Optional	Attributes		Name
class(ArModel),	intent(in)			::	model
real(kind=pr),	intent(in)			::	X(4)	Vector of variables
real(kind=pr),	intent(in)			::	s	Distance between the two fluids compositions to the main composition
real(kind=pr),	intent(in)			::	z0(:)	Molar fractions of the first fluid
real(kind=pr),	intent(in)			::	zi(:)	Molar fractions of the second fluid
real(kind=pr),	intent(in)			::	u(:)	Eigen-vector that defines the direction between the two compositions $n_i = z_i + s u_i \sqrt{z_i}$
real(kind=pr),	intent(out),	optional		::	u_new(:)	Eigen-vector corresponding to the smallest eigenvalue of the matrix $M_{ij} = \sqrt{z_i z_j} \frac{\partial \ln f_i}{\partial n_j}$
real(kind=pr),	intent(out),	optional		::	P	Pressure of the system [bar]

Return Value real(kind=pr)

Variables

Type	Visibility	Attributes		Name		Initial
real(kind=pr),	public		::	M(size(z0),size(z0))
real(kind=pr),	public		::	Pin
real(kind=pr),	public		::	T
real(kind=pr),	public		::	V
real(kind=pr),	public		::	dlnf_dn(size(z0),size(z0))
integer,	public		::	i
integer,	public		::	j
real(kind=pr),	public		::	lambda(size(z0))
real(kind=pr),	public		::	n(size(z0))
integer,	public		::	nc
real(kind=pr),	public		::	vectors(size(z0),size(z0))
real(kind=pr),	public		::	z(size(z0))