IMA Journal of Numerical Analysis Advance Access published online on September 7, 2009
IMA Journal of Numerical Analysis, doi:10.1093/imanum/drp022
Optimal stability for trapezoidal–backward difference split-steps

Department of Mathematics, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
Corresponding author. Email: gs{at}math.mit.edu
Received on 13 June 2008. Revised on 7 May 2009.
| Abstract |
|---|
The marginal stability of the trapezoidal method makes it dangerous to use for highly non-linear oscillations. Damping is provided by backward differences. The split-step combination (
t trapezoidal, (1 –
)
t for BDF2) retains second-order accuracy. The magic choice
allows the same Jacobian for both steps, when Newton's method solves these implicit difference equations. That choice is known to give the smallest error constant, and we prove that
also gives the largest region of linearized stability.
Key Words: backward differences; split-step; stability; trapezoidal
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