naginterfaces.library.ode.ivp_​stiff_​errest

naginterfaces.library.ode.ivp_stiff_errest(v, w, comm)

ivp_stiff_errest calculates the weighted norm of the local error estimate from inside a $\text{monitr}$ called from an integrator in submodule ode (e.g., see ivp_stiff_exp_fulljac()).

For full information please refer to the NAG Library document for d02za

https://support.nag.com/numeric/nl/nagdoc_30/flhtml/d02/d02zaf.html

Parameters

vfloat, array-like, shape $\left(\text{neq}\right)$

The vector, the weighted norm of which is to be evaluated by ivp_stiff_errest. $v$ is calculated internally by the integrator being used.

wfloat, array-like, shape $\left(\text{neq}\right)$

The weights, calculated internally by the integrator, to be used in the norm evaluation.

commdict, communication object

Communication structure.

This argument must have been initialized by prior calls to ivp_stiff_fulljac_setup() and one of ivp_stiff_dassl(), ivp_stiff_bdf() or ivp_stiff_blend().

Returns

errnrmfloat

$\parallel v\parallel$, the norm of the scaled local error estimate.

Warns

NagAlgorithmicWarning

(errno $1$)

The value of the norm would either overflow or is close to overflowing.

Notes

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

ivp_stiff_errest is for use with the direct communication integrators ivp_stiff_exp_fulljac(), ivp_stiff_exp_bandjac(), ivp_stiff_exp_sparjac(), ivp_stiff_imp_fulljac(), ivp_stiff_imp_bandjac() and ivp_stiff_imp_sparjac() and the reverse communication integrators ivp_stiff_exp_revcom() and ivp_stiff_imp_revcom(). It must be used only inside $\text{monitr}$ (if this option is selected) for the direct communication functions or on the equivalent return for the reverse communication functions. It may be used to evaluate the norm of the scaled local error estimate, $\parallel v\parallel$, where the weights used are contained in $w$ and the norm used is as defined by an earlier call to the integrator setup function (ivp_stiff_dassl(), ivp_stiff_bdf() or ivp_stiff_blend()). Its use is described under the description of $\text{monitr}$ in the specifications for the direct communication integrators mentioned above.