List of Runge–Kutta methods

List of Runge–Kutta methods

Runge–Kutta methods are methods for the numerical solution of the ordinary differential equation

:frac{d y}{d t} = f(t, y),

which take the form

:y_{n+1} = y_n + h sum_{i=1}^s b_i k_i,

:k_i = fleft(t_n + c_i h, y_n + h sum_{j = 1}^s a_{ij} k_j ight).

The methods listed on this page are each defined by its Butcher Tableau, which puts the coefficients of the method in a table as follows:

:egin{array}{c|cccc}c_1 & a_{11} & a_{12}& dots & a_{1s}\c_2 & a_{21} & a_{22}& dots & a_{2s}\vdots & vdots & vdots& ddots& vdots\c_s & a_{s1} & a_{s2}& dots & a_{ss} \hline & b_1 & b_2 & dots & b_s\end{array}

Explicit methods

The explicit methods are those where the matrix [a_{ij}] is lower triangular.

Forward Euler

This method is first order. The lack of stability and accuracy makes this popular primarily as a simple first introduction to numeric solution.

:egin{array}{c|c}0 & 0 \hline & 1 \end{array}

Kutta's third-order method

:egin{array}{c|ccc}0 & 0 & 0 & 0 \1/2 & 1/2 & 0 & 0 \1 & -1 & 2 & 0 \hline & 1/6 & 2/3 & 1/6 \end{array} Fact|date=October 2007

Classic fourth-order method

The "original" Runge–Kutta method.

:egin{array}{c|cccc}0 & 0 & 0 & 0 & 0\1/2 & 1/2 & 0 & 0 & 0\1/2 & 0 & 1/2 & 0 & 0\1 & 0 & 0 & 1 & 0\hline & 1/6 & 1/3 & 1/3 & 1/6\end{array}

Embedded methods

The embedded methods are designed to produce an estimate of the local truncation error of a single Runge-Kutta step, and as result, allow to control the error with adaptive stepsize. This is done by having two methods in the tableau, one with order p and one with order p-1.

The lower-order step is given by

: y^*_{n+1} = y_n + hsum_{i=1}^s b^*_i k_i,

where the k_i are the same as for the higher order method. Then the error is

: e_{n+1} = y_{n+1} - y^*_{n+1} = hsum_{i=1}^s (b_i - b^*_i) k_i,

which is "O"("h" "p"). The Butcher Tableau for this kind of method is extended to give the values of b^*_i:egin{array}{c|cccc}c_1 & a_{11} & a_{12}& dots & a_{1s}\c_2 & a_{21} & a_{22}& dots & a_{2s}\vdots & vdots & vdots& ddots& vdots\c_s & a_{s1} & a_{s2}& dots & a_{ss} \hline & b_1 & b_2 & dots & b_s\ & b_1^* & b_2^* & dots & b_s^*\end{array}

Heun-Euler

The simplest adaptive Runge-Kutta method involves combining the Heun method, which is order 2, with the Euler method, which is order 1. Its extended Butcher Tableau is::egin{array}{c|cc} 0\ 1& 1 \hline& 1/2& 1/2\ & 1 & 0end{array}

The error estimate is used to control the stepsize.

Bogacki–Shampine

The Bogacki–Shampine method has two methods of orders 3 and 2. Its extended Butcher Tableau is:

The first row of "b" coefficients gives the fifth-order accurate solution, and the second row has order four.

Dormand–Prince

The extended tableau for the Dormand–Prince method is

The first row of "b" coefficients gives the fifth-order accurate solution, and the second row has order four.

Implicit methods

Backward Euler

This method is first order. Unconditionally stable and non-oscillatory for linear diffusion problems.

:egin{array}{c|c}1 & 1 \hline & 1 \end{array}

Lobatto methods

There are three families of Lobatto methods, called IIIA, IIIB and IIIC. All are implicit methods, have order 2 s - 2 and they all have c_1=0 and c_s=1. Unlike any explicit method, it's possible for these methods to have the order greater than the number of stages. Lobatto lived before the classic fourth-order method was popularized by Runge and Kutta.

Lobatto IIIA methods

The Lobatto IIIA methods are collocation methods. The second-order method is closely analogous to the Crank–Nicolson method.

:egin{array}{c|cc}0 & 0 & 0 \1 & 1/2 & 1/2\hline & 1/2 & 1/2\end{array}

The fourth-order method is given by

:egin{array}{c|ccc}0 & 0 & 0 & 0 \1/2 & 5/24& 1/3 & -1/24\1 & 1/6 & 2/3 & 1/6 \hline & 1/6 & 2/3 & 1/6 \end{array}

Lobatto IIIB methods

The Lobatto IIIB methods are not collocation methods, but they can be viewed as discontinuous collocation methods harv|Hairer|Lubich|Wanner|2006|loc=§II.1.4. The second-order method is given by

:egin{array}{c|cc}0 & 1/2 & 0 \1 & 1/2 & 0 \hline & 1/2 & 1/2\end{array}

The fourth-order method is given by

:egin{array}{c|ccc}0 & 1/6 & -1/6& 0 \1/2 & 1/6 & 1/3 & 0 \1 & 1/6 & 5/6 & 0 \hline & 1/6 & 2/3 & 1/6 \end{array}

Lobatto IIIC methods

The Lobatto IIIC methods also are discontinuous collocation methods. The second-order method is given by

:egin{array}{c|cc}0 & 1/2 & -1/2\1 & 1/2 & 1/2 \hline & 1/2 & 1/2 \end{array}

The fourth-order method is given by

:egin{array}{c|ccc}0 & 1/6 & -1/3& 1/6 \1/2 & 1/6 & 5/12& -1/12\1 & 1/6 & 2/3 & 1/6 \hline & 1/6 & 2/3 & 1/6 \end{array}

References

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