nag_ode_ivp_rk_interp_eval (d02pjc) evaluates the interpolant calculated by
nag_ode_ivp_rk_interp_setup (d02phc), following an integration step performed by
nag_ode_ivp_rk_step_revcomm (d02pgc) to solve an initial value problem.
When integrating using the reverse communication Runge–Kutta integrator
nag_ode_ivp_rk_step_revcomm (d02pgc), the solution or its derivatives can be obtained inexpensively between steps by interpolation.
nag_ode_ivp_rk_interp_setup (d02phc) is called after a step by
nag_ode_ivp_rk_step_revcomm (d02pgc) from a previous value of
(
) to its current value,
(i.e., a
th successful time-step has been taken).
nag_ode_ivp_rk_interp_eval (d02pjc) can then be called to evaluate interpolated approximations of the function or its derivatives at any value of
in the interval
.
Brankin R W, Gladwell I and Shampine L F (1991) RKSUITE: A suite of Runge–Kutta codes for the initial value problems for ODEs SoftReport 91-S1 Southern Methodist University
- NE_ALLOC_FAIL
-
Dynamic memory allocation failed.
See
Section 2.3.1.2 in How to Use the NAG Library and its Documentation for further information.
- NE_BAD_PARAM
-
On entry, argument had an illegal value.
- NE_INT
-
On entry, .
Constraint: or .
On entry, .
Constraint: for , .
- NE_INT_2
-
On entry, and .
Constraint: for , .
- NE_INT_3
-
On entry, , and .
Constraint: for , .
- NE_INT_CHANGED
-
On entry, , but the value passed to the setup routine was .
On entry,
, but on interpolation setup
.
Constraint:
nwant must be unchanged from setup.
- NE_INTERNAL_ERROR
-
An internal error has occurred in this function. Check the function call and any array sizes. If the call is correct then please contact
NAG for assistance.
See
Section 2.7.6 in How to Use the NAG Library and its Documentation for further information.
- NE_MISSING_CALL
-
On entry, a previous call to the setup function has not been made or the communication arrays have become corrupted, or a catastrophic error has already been detected elsewhere.
You cannot continue integrating the problem.
You cannot call this function before you have called the interpolation setup.
- NE_NO_LICENCE
-
Your licence key may have expired or may not have been installed correctly.
See
Section 2.7.5 in How to Use the NAG Library and its Documentation for further information.
- NE_PREV_CALL_INI
-
The previous call to the interpolation setup function returned an error.
The computed values will be of a similar accuracy to that computed by
nag_ode_ivp_rk_step_revcomm (d02pgc).
None.