MRKISS 2025-09-10
A tiny library with zero dependencies that aims to make it easy to use & experiment with explicit Runge-Kutta methods.
Loading...
Searching...
No Matches
mrkiss_erk_midpoint_2 Module Reference

Butcher tableau for midpoint 2 step, order (2) Runge-Kutta method. More...

Variables

integer, parameter s = 2
 The order of the overall method.
integer, parameter m = 1
 Number of methods.
real(kind=rk), dimension(s, s), parameter a
 The \(\mathbf{a}\) matrix for the Butcher Tableau.
real(kind=rk), dimension(s, m), parameter b
 The \(\mathbf{b}\) matrix for the Butcher Tableau.
real(kind=rk), dimension(s), parameter c
 The \(\mathbf{c}\) matrix for the Butcher Tableau.
integer, dimension(m), parameter p = [2]
 The method orders.
integer, dimension(m), parameter se = [2]
 Number of stages for each method.

Detailed Description

Butcher tableau for midpoint 2 step, order (2) Runge-Kutta method.

IMO
Included for historical reasons.
Known Aliases
'RK22' (Butcher), 'midpoint method', 'the modpoint rule', 'Explicit midpoint method', 'Runge-2', 'R2'
Stability Image Links
References:
  • Butcher (2016); Numerical Methods for Ordinary Differential Equations. 3ed; p98-99; zotero://select/items/0_V7UTIRPT

Variable Documentation

◆ s

integer, parameter mrkiss_erk_midpoint_2::s = 2

The order of the overall method.

Definition at line 61 of file mrkiss_erk_midpoint_2.f90.

◆ m

integer, parameter mrkiss_erk_midpoint_2::m = 1

Number of methods.

Definition at line 63 of file mrkiss_erk_midpoint_2.f90.

◆ a

real(kind=rk), dimension(s,s), parameter mrkiss_erk_midpoint_2::a

The \(\mathbf{a}\) matrix for the Butcher Tableau.

Definition at line 65 of file mrkiss_erk_midpoint_2.f90.

65 real(kind=rk), parameter :: a(s,s) = reshape([ 0.0_rk, 0.0_rk, &
66 1.0_rk, 0.0_rk], [s, s]) / 2.0_rk

◆ b

real(kind=rk), dimension(s,m), parameter mrkiss_erk_midpoint_2::b

The \(\mathbf{b}\) matrix for the Butcher Tableau.

Definition at line 68 of file mrkiss_erk_midpoint_2.f90.

68 real(kind=rk), parameter :: b(s,m) = reshape([ 0.0_rk, 1.0_rk], [s, m]) / 1.0_rk

◆ c

real(kind=rk), dimension(s), parameter mrkiss_erk_midpoint_2::c

The \(\mathbf{c}\) matrix for the Butcher Tableau.

Definition at line 70 of file mrkiss_erk_midpoint_2.f90.

70 real(kind=rk), parameter :: c(s) = [ 0.0_rk, 1.0_rk] / 2.0_rk

◆ p

integer, dimension(m), parameter mrkiss_erk_midpoint_2::p = [2]

The method orders.

Definition at line 72 of file mrkiss_erk_midpoint_2.f90.

◆ se

integer, dimension(m), parameter mrkiss_erk_midpoint_2::se = [2]

Number of stages for each method.

Definition at line 74 of file mrkiss_erk_midpoint_2.f90.