bdf2, a Fortran77 code which solves one or more ordinary differential equations (ODE) using the (implicit) backward difference formula order 2 (BDF2), with a version of fsolve() handling the associated nonlinear equation, and using a fixed time step.
The computer code and data files described and made available on this web page are distributed under the MIT license.
bdf2 is available in a C version and a C++ version and a Fortran77 version and a Fortran90 version and a MATLAB version and an Octave version and a Python version.
backward_euler, a Fortran90 code which solves one or more ordinary differential equations (ODE) using the (implicit) backward Euler method, using a version of fsolve() for the implicit equation.
euler, a Fortran90 code which solves one or more ordinary differential equations (ODE) using the forward Euler method.
fsolve, a Fortran90 code which solves systems of nonlinear equations, inspired by the fsolve() function in minpack(), with special interfaces fsolve_bdf2(), fsolve_be() and fsolve_tr() for handling systems associated with implicit ODE solvers of type bdf2, backward Euler, midpoint, or trapezoidal.
midpoint, a Fortran77 code which solves one or more ordinary differential equations (ODE) using the (implicit) midpoint method, with a version of fsolve() handling the associated nonlinear equations, and using a fixed time step.
rk4, a Fortran90 code which applies the fourth order Runge-Kutta (RK) algorithm to estimate the solution of an ordinary differential equation (ODE).
rkf45, a Fortran90 code which implements the Runge-Kutta-Fehlberg ODE solver.
trapezoidal, a Fortran90 code which solves one or more ordinary differential equations (ODE) using the (implicit) trapezoidal method, and a version of fsolve() to handle the nonlinear equation.