Implicit methods List of Runge–Kutta methods
1 implicit methods
1.1 backward euler
1.2 implicit midpoint
1.3 gauss–legendre methods
1.4 lobatto methods
1.4.1 lobatto iiia methods
1.4.2 lobatto iiib methods
1.4.3 lobatto iiic methods
1.4.4 lobatto iiic* methods
1.4.5 generalized lobatto methods
1.5 radau methods
1.5.1 radau ia methods
1.5.2 radau iia methods
implicit methods
backward euler
the backward euler method first order. unconditionally stable , non-oscillatory linear diffusion problems.
1
1
1
{\displaystyle {\begin{array}{c|c}1&1\\\hline &1\\\end{array}}}
implicit midpoint
the implicit midpoint method of second order. simplest method in class of collocation methods known gauss methods. symplectic integrator.
1
/
2
1
/
2
1
{\displaystyle {\begin{array}{c|c}1/2&1/2\\\hline &1\end{array}}}
gauss–legendre methods
these methods based on points of gauss–legendre quadrature. gauss–legendre method of order 4 has butcher tableau:
1
2
−
3
6
1
4
1
4
−
3
6
1
2
+
3
6
1
4
+
3
6
1
4
1
2
1
2
1
2
+
1
2
3
1
2
−
1
2
3
{\displaystyle {\begin{array}{c|cc}{\frac {1}{2}}-{\frac {\sqrt {3}}{6}}&{\frac {1}{4}}&{\frac {1}{4}}-{\frac {\sqrt {3}}{6}}\\{\frac {1}{2}}+{\frac {\sqrt {3}}{6}}&{\frac {1}{4}}+{\frac {\sqrt {3}}{6}}&{\frac {1}{4}}\\\hline &{\frac {1}{2}}&{\frac {1}{2}}\\&{\frac {1}{2}}+{\frac {1}{2}}{\sqrt {3}}&{\frac {1}{2}}-{\frac {1}{2}}{\sqrt {3}}\\\end{array}}}
the gauss–legendre method of order 6 has butcher tableau:
1
2
−
15
10
5
36
2
9
−
15
15
5
36
−
15
30
1
2
5
36
+
15
24
2
9
5
36
−
15
24
1
2
+
15
10
5
36
+
15
30
2
9
+
15
15
5
36
5
18
4
9
5
18
−
5
6
8
3
−
5
6
{\displaystyle {\begin{array}{c|ccc}{\frac {1}{2}}-{\frac {\sqrt {15}}{10}}&{\frac {5}{36}}&{\frac {2}{9}}-{\frac {\sqrt {15}}{15}}&{\frac {5}{36}}-{\frac {\sqrt {15}}{30}}\\{\frac {1}{2}}&{\frac {5}{36}}+{\frac {\sqrt {15}}{24}}&{\frac {2}{9}}&{\frac {5}{36}}-{\frac {\sqrt {15}}{24}}\\{\frac {1}{2}}+{\frac {\sqrt {15}}{10}}&{\frac {5}{36}}+{\frac {\sqrt {15}}{30}}&{\frac {2}{9}}+{\frac {\sqrt {15}}{15}}&{\frac {5}{36}}\\\hline &{\frac {5}{18}}&{\frac {4}{9}}&{\frac {5}{18}}\\&-{\frac {5}{6}}&{\frac {8}{3}}&-{\frac {5}{6}}\end{array}}}
lobatto methods
there 3 main families of lobatto methods, called iiia, iiib , iiic (in classial mathematical literature, symbols , ii reserved 2 types of radau methods). these named after rehuel lobatto. implicit methods, have order 2s − 2 , have c1 = 0 , cs = 1. unlike explicit method, s possible these methods have order greater number of stages. lobatto lived before classic fourth-order method popularized runge , kutta.
lobatto iiia methods
the lobatto iiia methods collocation methods. second-order method known trapezoidal rule:
0
0
0
1
1
/
2
1
/
2
1
/
2
1
/
2
1
0
{\displaystyle {\begin{array}{c|cc}0&0&0\\1&1/2&1/2\\\hline &1/2&1/2\\&1&0\\\end{array}}}
the fourth-order method given by
0
0
0
0
1
/
2
5
/
24
1
/
3
−
1
/
24
1
1
/
6
2
/
3
1
/
6
1
/
6
2
/
3
1
/
6
−
1
2
2
−
1
2
{\displaystyle {\begin{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\\&-{\frac {1}{2}}&2&-{\frac {1}{2}}\\\end{array}}}
this methods a-stable, not l-stable , b-stable.
lobatto iiib methods
the lobatto iiib methods not collocation methods, can viewed discontinuous collocation methods (hairer, lubich & wanner 2006, §ii.1.4). second-order method given by
0
1
/
2
0
1
1
/
2
0
1
/
2
1
/
2
1
0
{\displaystyle {\begin{array}{c|cc}0&1/2&0\\1&1/2&0\\\hline &1/2&1/2\\&1&0\\\end{array}}}
the fourth-order method given by
0
1
/
6
−
1
/
6
0
1
/
2
1
/
6
1
/
3
0
1
1
/
6
5
/
6
0
1
/
6
2
/
3
1
/
6
−
1
2
2
−
1
2
{\displaystyle {\begin{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\\&-{\frac {1}{2}}&2&-{\frac {1}{2}}\\\end{array}}}
lobatto iiib methods a-stable, not l-stable , b-stable.
lobatto iiic methods
the lobatto iiic methods discontinuous collocation methods. second-order method given by
0
1
/
2
−
1
/
2
1
1
/
2
1
/
2
1
/
2
1
/
2
1
0
{\displaystyle {\begin{array}{c|cc}0&1/2&-1/2\\1&1/2&1/2\\\hline &1/2&1/2\\&1&0\\\end{array}}}
the fourth-order method given by
0
1
/
6
−
1
/
3
1
/
6
1
/
2
1
/
6
5
/
12
−
1
/
12
1
1
/
6
2
/
3
1
/
6
1
/
6
2
/
3
1
/
6
−
1
2
2
−
1
2
{\displaystyle {\begin{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\\&-{\frac {1}{2}}&2&-{\frac {1}{2}}\\\end{array}}}
they l-stable. algebraically stable , b-stable, makes them suitable stiff problems.
lobatto iiic* methods
the lobatto iiic* methods known lobatto iii methods (butcher, 2008), butcher’s lobatto methods (hairer et al, 1993), , lobatto iiic methods (sun, 2000) in literature. second-order method given by
0
0
0
1
1
0
1
/
2
1
/
2
{\displaystyle {\begin{array}{c|cc}0&0&0\\1&1&0\\\hline &1/2&1/2\\\end{array}}}
the fourth-order method given by
0
0
0
0
1
/
2
1
/
4
1
/
4
0
1
0
1
0
1
/
6
2
/
3
1
/
6
{\displaystyle {\begin{array}{c|ccc}0&0&0&0\\1/2&1/4&1/4&0\\1&0&1&0\\\hline &1/6&2/3&1/6\\\end{array}}}
these methods not a-stable, b-stable or l-stable. lobatto iiic* method
s
=
2
{\displaystyle s=2}
called explicit trapezoidal rule.
generalized lobatto methods
one can consider general family of methods 3 real parameters
(
α
a
,
α
b
,
α
c
)
{\displaystyle (\alpha _{a},\alpha _{b},\alpha _{c})}
considering lobatto coefficients of form
a
i
,
j
(
α
a
,
α
b
,
α
c
)
=
α
a
a
i
,
j
a
+
α
b
a
i
,
j
b
+
α
c
a
i
,
j
c
+
α
c
∗
a
i
,
j
c
∗
{\displaystyle a_{i,j}(\alpha _{a},\alpha _{b},\alpha _{c})=\alpha _{a}a_{i,j}^{a}+\alpha _{b}a_{i,j}^{b}+\alpha _{c}a_{i,j}^{c}+\alpha _{c*}a_{i,j}^{c*}}
,
where
α
c
∗
=
1
−
α
a
−
α
b
−
α
c
{\displaystyle \alpha _{c*}=1-\alpha _{a}-\alpha _{b}-\alpha _{c}}
.
for example, lobatto iiid family introduced in (nørsett , wanner, 1981), called lobatto iiinw, given by
0
1
/
2
1
/
2
1
−
1
/
2
1
/
2
1
/
2
1
/
2
{\displaystyle {\begin{array}{c|cc}0&1/2&1/2\\1&-1/2&1/2\\\hline &1/2&1/2\\\end{array}}}
and
0
1
/
6
0
−
1
/
6
1
/
2
1
/
12
5
/
12
0
1
1
/
2
1
/
3
1
/
6
1
/
6
2
/
3
1
/
6
{\displaystyle {\begin{array}{c|ccc}0&1/6&0&-1/6\\1/2&1/12&5/12&0\\1&1/2&1/3&1/6\\\hline &1/6&2/3&1/6\\\end{array}}}
these methods correspond
α
a
=
2
{\displaystyle \alpha _{a}=2}
,
α
b
=
2
{\displaystyle \alpha _{b}=2}
,
α
c
=
−
1
{\displaystyle \alpha _{c}=-1}
, ,
α
c
∗
=
−
2
{\displaystyle \alpha _{c*}=-2}
. methods l-stable. algebraically stable , b-stable.
radau methods
radau methods implicit methods (matrix of such methods can have structure). radau methods attain order 2s − 1 s stages. radau methods a-stable, expensive implement. can suffer order reduction. first order radau method similar backward euler method.
radau ia methods
the third-order method given by
0
1
/
4
−
1
/
4
2
/
3
1
/
4
5
/
12
1
/
4
3
/
4
{\displaystyle {\begin{array}{c|cc}0&1/4&-1/4\\2/3&1/4&5/12\\\hline &1/4&3/4\\\end{array}}}
the fifth-order method given by
0
1
9
−
1
−
6
18
−
1
+
6
18
3
5
−
6
10
1
9
11
45
+
7
6
360
11
45
−
43
6
360
3
5
+
6
10
1
9
11
45
+
43
6
360
11
45
−
7
6
360
1
9
4
9
+
6
36
4
9
−
6
36
{\displaystyle {\begin{array}{c|ccc}0&{\frac {1}{9}}&{\frac {-1-{\sqrt {6}}}{18}}&{\frac {-1+{\sqrt {6}}}{18}}\\{\frac {3}{5}}-{\frac {\sqrt {6}}{10}}&{\frac {1}{9}}&{\frac {11}{45}}+{\frac {7{\sqrt {6}}}{360}}&{\frac {11}{45}}-{\frac {43{\sqrt {6}}}{360}}\\{\frac {3}{5}}+{\frac {\sqrt {6}}{10}}&{\frac {1}{9}}&{\frac {11}{45}}+{\frac {43{\sqrt {6}}}{360}}&{\frac {11}{45}}-{\frac {7{\sqrt {6}}}{360}}\\\hline &{\frac {1}{9}}&{\frac {4}{9}}+{\frac {\sqrt {6}}{36}}&{\frac {4}{9}}-{\frac {\sqrt {6}}{36}}\\\end{array}}}
radau iia methods
the ci of method zeros of
p
s
(
2
x
−
1
)
−
p
s
−
1
(
2
x
−
1
)
=
0
,
{\displaystyle p_{s}(2x-1)-p_{s-1}(2x-1)=0,}
where
p
s
{\displaystyle p_{s}}
legendre polynomial of degree s. third-order method given by
1
/
3
5
/
12
−
1
/
12
1
3
/
4
1
/
4
3
/
4
1
/
4
{\displaystyle {\begin{array}{c|cc}1/3&5/12&-1/12\\1&3/4&1/4\\\hline &3/4&1/4\\\end{array}}}
the fifth-order method given by
2
5
−
6
10
11
45
−
7
6
360
37
225
−
169
6
1800
−
2
225
+
6
75
2
5
+
6
10
37
225
+
169
6
1800
11
45
+
7
6
360
−
2
225
−
6
75
1
4
9
−
6
36
4
9
+
6
36
1
9
4
9
−
6
36
4
9
+
6
36
1
9
{\displaystyle {\begin{array}{c|ccc}{\frac {2}{5}}-{\frac {\sqrt {6}}{10}}&{\frac {11}{45}}-{\frac {7{\sqrt {6}}}{360}}&{\frac {37}{225}}-{\frac {169{\sqrt {6}}}{1800}}&-{\frac {2}{225}}+{\frac {\sqrt {6}}{75}}\\{\frac {2}{5}}+{\frac {\sqrt {6}}{10}}&{\frac {37}{225}}+{\frac {169{\sqrt {6}}}{1800}}&{\frac {11}{45}}+{\frac {7{\sqrt {6}}}{360}}&-{\frac {2}{225}}-{\frac {\sqrt {6}}{75}}\\1&{\frac {4}{9}}-{\frac {\sqrt {6}}{36}}&{\frac {4}{9}}+{\frac {\sqrt {6}}{36}}&{\frac {1}{9}}\\\hline &{\frac {4}{9}}-{\frac {\sqrt {6}}{36}}&{\frac {4}{9}}+{\frac {\sqrt {6}}{36}}&{\frac {1}{9}}\\\end{array}}}
^ http://homepage.math.uiowa.edu/~ljay/publications.dir/lobatto.pdf
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