CWG_ODE
Three ODE Solvers by William Gear.

CWG_ODE is a FORTRAN77 library which includes three solvers for systems of ordinary differential equations, written by C William Gear.

Languages:

CWG_ODE is available in a FORTRAN77 version.

Related Data and Programs:

DFIELD8, a MATLAB program which interactively displays the direction field of a differential equation, by John Polking.

DRIV, a FORTRAN77 library which solves real or complex systems of ordinary differential equations;

NMS, a FORTRAN90 library which includes the DDRIV< package of ODE solvers.

ODE, a FORTRAN77 library which solves a system of ordinary differential equations, by Shampine and Gordon.

ODEPACK, a FORTRAN77 library which contains nine ODE solvers, including LSODE, LSODES, LSODA, LSODAR, LSODPK, LSODKR, LSODI, LSOIBT, and LSODIS, by Alan Hindmarsh.

PPLANE8, a MATLAB program which interactively displays the phase plane of a differential equation, by John Polking.

RK4, a FORTRAN77 library which applies the fourth order Runge-Kutta algorithm to estimate the solution of an ordinary differential equation at the next time step.

RKF45, a FORTRAN77 library which implements the Runge-Kutta-Fehlberg ODE solver.

TEST_ODE, a FORTRAN90 library which contains routines which define some test problems for ODE solvers.

Reference:

1. Charles Gear,
   Numerical Initial Value Problems in Ordinary Differential Equations,
   Prentice-Hall, 1971,
   ISBN: 0136266061,
   LC: QA372.G4.

Source Code:

• cwg_ode.f, the source code.
• cwg_ode.sh, commands to compile the source code.

Examples and Tests:

• cwg_ode_prb.f, a sample calling program.
• cwg_ode_prb.sh, commands to compile and run the sample program.
• cwg_ode_prb_output.txt, the output file.

List of Routines:

• SRKODE applies a Runge-Kutta method to differential equations.
• SRK1 performs one Runge Kutta step.
• SPRODE uses polynomial or rational approximation to solve ODE's.
• SMVODE solves an ODE with a multi-value method.
• PDUMMY is a dummy derivative routine for calls to SMVODE with mf.ne.1.
• SGEFA factors a matrix by gaussian elimination.
• SGESL solves a linear system that was factored by SGEFA.
• ISAMAX finds the index of element having maximum absolute value.
• SAXPY computes constant times a vector plus a vector.
• SDOT forms the dot product of two vectors.
• SSCAL scales a vector by a constant.
• TIMESTAMP prints out the current YMDHMS date as a timestamp.

You can go up one level to the FORTRAN77 source codes.