runge.h

/*
 * Runge-Kutta integrator originally written for PKDGRAV by Thomas
 * Quinn
 */
void
RungeKutta(void *CTX, 
       void (*deriv)(void *, double, double *, double*),
       int nDep,        /* number of dependent variables */
       double tin,      /* independent variable */
       double *xin,     /* array of input */
       double tout,
       double *xout,        /* array of output */
       int nSteps);