RKSUITE is an excellent collection of codes based on Runge-Kutta methods for the numerical solution of an IVP for a first order system of ODEs and is available in the public domain. It supersedes some very widely used codes written by the authors and their coauthors, namely the RKF45 code and its descendant DDERKF in the SLATEC library and DO2PAF and associated codes in the NAG Fortran library. RKSUITE is written in standard FORTRAN 77 and is distributed in source form. The advanced algorithms provide more functionality than is found in earlier codes, including new more efficient formulas, interpolation, automatic selection of the initial step size, a stiffness diagnostic, and global error assessment. The advanced software design includes a novel interface permitting both interval- and step-oriented solutions and is highly portable. The documentation includes detailed instructions for the effective use of the codes, a collection of templates illustrating the use of the codes for common tasks, output from running the templates in a number of variations, and comprehensive instructions for installing the codes.
RKSUITE implements three Runge-Kutta pairs: (2,3), (4,5), and (7,8). The (4,5) pair, for example, uses both a 4th and a 5th order approximation to estimate the error in the 4th order formula; using extrapolation, it then produces a formula of order 5. Similarly, the (2,3) pair produces a formula of order 3 and the (7,8) pair a formula of order 8.
The documentation for RKSUITE provided in RKSUITE.DOC is especially recommended. It is fairly short, carefully written document, explaining some of the internal workings of the suit of codes. The reader should pay particular attention to the description of error control and the effect on delivered accuracy. The documentation also contains an excellent set of references that describe the formulas and algorithms used in RKSUITE; references are also included that describe the design, implementation and testing of codes based on explicit Runge-Kutta formulas. The current code was written by R. Brankin (NAG). I. Gladwell (SMU) and L. Shampine (SMU) [7].
A copy of RKSUITE, together with sample drivers, can be obtained from ``netlib'' using anonymous ftp as follows:
For a complete listing of what is available from ``netlib'', mail netlib @ornl.gov and type send index in the body of your message. The Internet address ``netlib@ornl.gov'' refers to a gateway machine at Oak Ridge National Laboratory in Oak Ridge, Tennessee. This address should be understood on all major networks.