, 8 min read
Parasitic roots of various cyclic linear multistep methods
Original post is here eklausmeier.goip.de/blog/2025/12-06-parasitic-roots-of-various-cyclic-linear-multistep-methods.
1. Tischer's formulas
All cyclic linear multistep methods were designed to only have root at 1, and all other parasitic roots to be zero.
See Tischer, Peter E. and Sacks-Davis, Ron: “A New Class of Cyclic Multistep Formulae for Stiff Systems”.
2. Donelson & Hansen formulas
See Donelson III, John and Hansen, Eldon: “Cyclic Composite Multistep Predictor-Corrector Methods”, SIAM Journal on Numerical Analysis, Vol 8, 1971, pp.137—157.
DH1
| root | real | imaginary | absolute value |
|---|---|---|---|
| 0 | 1.00000000 | 0.00000000 | 1.00000000 |
| 1 | 0.00000000 | 0.00000000 | 0.00000000 |
| 2 | 0.00000000 | 0.00000000 | 0.00000000 |
DH2
| root | real | imaginary | absolute value |
|---|---|---|---|
| 0 | -0.31605416 | 0.94874115 | 1.00000000 |
| 1 | -0.31605416 | -0.94874115 | 1.00000000 |
| 2 | 1.00000000 | 0.00000000 | 1.00000000 |
DH3
| root | real | imaginary | absolute value |
|---|---|---|---|
| 0 | 1.00000000 | 0.00000000 | 1.00000000 |
| 1 | 0.04526646 | 0.00000000 | 0.04526646 |
| 2 | 0.00000000 | 0.00000000 | 0.00000000 |
DH4
| root | real | imaginary | absolute value |
|---|---|---|---|
| 0 | 1.00000000 | 0.00000000 | 1.00000000 |
| 1 | -0.09090909 | 0.00000000 | 0.09090909 |
| 2 | 0.00000000 | -0.00000000 | 0.00000000 |
DH5
| root | real | imaginary | absolute value |
|---|---|---|---|
| 0 | 1.00000000 | 0.00000000 | 1.00000000 |
| 1 | -0.01125522 | 0.93329189 | 0.93335976 |
| 2 | -0.01125522 | -0.93329189 | 0.93335976 |
| 3 | 0.00000000 | 0.00000000 | 0.00000000 |
DH6
| root | real | imaginary | absolute value |
|---|---|---|---|
| 0 | 1.00000000 | 0.00000000 | 1.00000000 |
| 1 | -0.37892727 | -0.00000000 | 0.37892727 |
| 2 | 0.13825231 | 0.00000000 | 0.13825231 |
| 3 | 0.00000000 | 0.00000000 | 0.00000000 |
3. Mihelcic's formulas
See Matija Mihelčić (Mihelcic) and K. Wingerath: “A(α)-stable Cyclic Composite Multistep Methods of Orders 6 and 7 for Numerical Integration of Stiff Ordinary Differential Equations”, ZAMM, Band 61, 1981, pp.261—264
Mihelcic4
| root | real | imaginary | absolute value |
|---|---|---|---|
| 0 | 1.00000000 | 0.00000000 | 1.00000000 |
| 1 | 0.50107560 | 0.00000000 | 0.50107560 |
| 2 | -0.42506560 | 0.00000000 | 0.42506560 |
Mihelcic5
| root | real | imaginary | absolute value |
|---|---|---|---|
| 0 | 1.00000000 | 0.00000000 | 1.00000000 |
| 1 | -0.38334289 | 0.00000000 | 0.38334289 |
| 2 | -0.21218358 | 0.00000000 | 0.21218358 |
Mihelcic6
| root | real | imaginary | absolute value |
|---|---|---|---|
| 0 | 1.00000000 | -0.00000000 | 1.00000000 |
| 1 | -0.90745413 | -0.00000000 | 0.90745413 |
| 2 | 0.41922349 | 0.00000000 | 0.41922349 |
| 3 | 0.06530404 | -0.00000000 | 0.06530404 |
Mihelcic7
| root | real | imaginary | absolute value |
|---|---|---|---|
| 0 | 1.00000000 | 0.00000000 | 1.00000000 |
| 1 | 0.16549909 | -0.00000000 | 0.16549909 |
| 2 | 0.09946611 | 0.00000000 | 0.09946611 |
| 3 | 0.02567147 | -0.00000000 | 0.02567147 |
| 4 | -0.00642008 | 0.00000000 | 0.00642008 |