rkf45 is primarily designed to solve non-stiff and mildly stiff differential equations when derivative evaluations are inexpensive. rkf45 should generally not be used when the user is demanding high accuracy. 在计算量不大的计算中，rkf45主要用于求解非刚性和轻微刚性的常微分方程。
| Type | Intent | Optional | Attributes | Name | ||
|---|---|---|---|---|---|---|
| procedure(fcn) | :: | f | ||||
| integer, | intent(in) | :: | neqn | |||
| real(kind=rk), | intent(inout) | :: | y(neqn) | |||
| real(kind=rk), | intent(inout) | :: | t | |||
| real(kind=rk), | intent(in) | :: | tout | |||
| real(kind=rk), | intent(inout) | :: | relerr | |||
| real(kind=rk), | intent(in) | :: | abserr | |||
| integer, | intent(inout) | :: | iflag | |||
| real(kind=rk), | intent(inout) | :: | work(*) | |||
| integer, | intent(inout) | :: | iwork(5) |