# Testset of Stiff ODEs

All the problems of this testset are described
in our
monograph
"Solving Ordinary Differential Equations. Volume II".

Fortran 77
subroutines of the equation (and Jacobian), and of the drivers for the
stiff
codes
RADAU5, RODAS, SEULEX are available.

If you have problems with running these drivers on your computer,
please, contact
Ernst.Hairer@math.unige.ch.
It may be necessary to change the CALL DTIME(TARRAY) by a call
to your local clock.

*Remark.* Further interesting test problems can be obtained from the
testset for
IVP solvers
of Bari (former CWI Amsterdam), and from the
IVP
Software page of Jeff Cash; see also the
IVP software
page of Frnacesca Mazzia and Felice Iavernaro.

## Stiff Problems

**VDPOL** (Van der Pol oscillator): available are the
equation, a
driver for RADAU5, a
driver for RODAS, a
driver for SEULEX, and the
exact solution.
**ROBER** (Problem of Robertson, chemical reaction):
available are the
equation, a
driver for RADAU5, a
driver for RODAS, a
driver for SEULEX, and the
exact solution.
**OREGO** (Oregonator, Belusov-Zhabotinskii reaction): available are the
equation, a
driver for RADAU5, a
driver for RODAS, a
driver for SEULEX, and the
exact solution.
**HIRES** (chemical reaction, mildly stiff): available are the
equation, a
driver for RADAU5, a
driver for RODAS, a
driver for SEULEX, and the
exact solution.
**E5** (chemical reaction, taken from "stiff detest"):
available are the
equation, a
driver for RADAU5, a
driver for RODAS, a
driver for SEULEX, and the
exact solution.
**PLATE** (movement of rectangular plate, discretized PDE): available are the
equation, a
driver for RADAU5, a
driver for RODAS, a
driver for SEULEX, and the
exact solution.
**BEAM** (elastic beam): available are the
equation, a
driver for RADAU5, a
driver for RODAS, a
driver for SEULEX, and the
exact solution.
**CUSP** (cusp catastrophe model): available are the
equation, a
driver for RADAU5, a
driver for SEULEX, and the
exact solution.
**BRUSS** (Brusselator with 1D diffusion): available are the
equation, a
driver for RADAU5, a
driver for RODAS, a
driver for SEULEX, and the
exact solution.
**KS** (Kuramoto-Sivashinsky equation,
PDE discreitzed with the
pseudo-spectral method): available are the
equation, a
driver for RADAU5, a
driver for SEULEX, and the
exact solution.
**BECKDO** (Becker-Döring model): available are the
equation, a
driver for RADAU5, a
driver for RODAS, a
driver for SEULEX, and the
exact solution. For the use of these drivers one has to replace
the file dc_decsol.f by
dc_decsol_bd.f.
**BRUSS-2D** (Brusselator with 2D diffusion): available are the
equation, a
driver for RADAU5, a
driver for SEULEX, and the
exact solution. For the use of these drivers one has to replace
the file dc_decsol.f by
dc_decsol_2d.f.

## Mechanical Problems