# naginterfaces.library.ode.ivp_​stiff_​nat_​interp¶

naginterfaces.library.ode.ivp_stiff_nat_interp(xsol, m, comm, neq, x, nqu, hu, h)[source]

ivp_stiff_nat_interp interpolates components of the solution of a system of first-order ordinary differential equations from information provided by the integrators in submodule ode.

For full information please refer to the NAG Library document for d02xj

https://www.nag.com/numeric/nl/nagdoc_29/flhtml/d02/d02xjf.html

Parameters
xsolfloat

The point at which the first components of the solution are to be evaluated. should not be an extrapolation point, that is should satisfy . Extrapolation is permitted but not recommended.

mint

, the number of components of the solution whose values at are required. The first components are evaluated.

commdict, communication object

Communication structure populated by a previous call to the integrator.

neqint

The value used for the argument when calling the integrator.

xfloat

The latest value at which the solution has been computed, as provided in the argument on return from the optional output ivp_stiff_integ_diag().

nquint

The order of the method used up to the latest value at which the solution has been computed, as provided in the argument on return from the optional output ivp_stiff_integ_diag().

hufloat

The last successful step used, that is the step used in the integration to get to , as provided in the argument on return from the optional output ivp_stiff_integ_diag().

hfloat

The next step size to be attempted in the integration, as provided in the argument on return from the optional output ivp_stiff_integ_diag().

Returns
solfloat, ndarray, shape

The calculated value of the th component of the solution at , for .

Raises
NagValueError
(errno )

On entry, and .

Constraint: .

(errno )

On entry, .

Constraint: .

(errno )

On entry, and .

Constraint: .

(errno )

On entry, and .

Constraint: .

(errno )

On entry, .

Constraint: .

(errno )

On entry, .

Constraint: .

(errno )

On entry, .

Constraint: .

(errno )

On entry, .

(errno )

On entry, .

Warns
NagAlgorithmicWarning
(errno )

On entry, , and .

Constraint: should not be an extrapolation point.

Notes

No equivalent traditional C interface for this routine exists in the NAG Library.

ivp_stiff_nat_interp evaluates the first components of the solution of a system of ordinary differential equations at any point using natural polynomial interpolation based on information generated by the integrator. This information must be passed unchanged to ivp_stiff_nat_interp. ivp_stiff_nat_interp should not normally be used to extrapolate outside the range of values obtained from the above functions.