Diagnonally Implicit Multistage Class #440
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tommbendall
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Sep 18, 2023
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tommbendall
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Oct 24, 2023
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This code change adds an Implicit Multistage class which allows for general diagonally implicit Runge-Kutta schemes by passing in a Butcher Tableau. It also adds the Implicit Midpoint and a two stage scheme developed by Qin and Zhang. The butcher tableau is of the form:
[a_00 0 . 0 ]
[a_10 a_11 . 0 ]
[ . . . . ]
[ b_0 b_1 . b_s]
I have tested a Trapezium Rule version vs the regular TrapeziumRule for Williamson 1 & 6, and the errors are of the order 10^-9. QinZhang and ImplicitMidpoint also run nicely for Williamson 1 and 6.