XLPack 7.0
XLPack Numerical Library (C API) Reference Manual
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◆ dverk_int()

void dverk_int ( int  n,
double  t,
double  y[],
double  c[],
double  work[] 
)

Initial value problem of ordinary differential equations (6(5)-th order Runge-Kutta-Verner method) (Interpolation for dense output)

NOTE - THIS ROUTINE IS DEPRECATED AND WILL BE REMOVED IN THE NEXT VERSION.

Purpose
This is the support routine which interpolates the solution for dense output when an initial value problem of a system of ordinary differential equations is solved by dverk. For the details of interpolants used here, refer to the reference below.

dverk must be called with setting parameter c[8] = 2 to enable dense output. Note that larger work array work[] is required. Further, one additional function evaluation per accepted step is required.
When returned from dverk with ind = 5 (ind = 3 for last step) after accepted step, the interporated solution within last step interval can be computed by using this routine.
Parameters
[in]nNumber of differential equations. (n >= 1)
[in]tt at which the interpolated solution is computed.
t must be in the interval of the last step. That is, t1 <= t <= t2 where t1 is the value of t on the previous return from dverk with ind = 5, and t2 is the value on the last return with info = 5.
[out]y[]Array y[ly] (ly >= n)
Interpoolated solution at t.
[in]c[]Array c[lc]
Parameter array c[] used by dverk.
[in]work[]Array work[lwork]
Work array work[] used by dverk.
Reference
W H Enright et al. "Interpolants for Runge-Kutta Formulas" ACM Transactions on Mathematical Software Vol.12, No.3, 1986, pp.193-218