Runge-Kutta Method

Numerical Methods

Source inspiration: (Mathew 2000-2019).

Animations

Each animation below shows the RK4 solution trace building step by step for the IVP \(y' = 1 - t\sqrt[3]{y}\), \(y(0)=1\) over \([0,5]\). Each frame adds one new solution point; the connecting curve reveals the numerical trajectory. RK4 computes four slope estimates (\(k_1, k_2, k_3, k_4\)) per step and takes a weighted average — giving \(O(h^4)\) local accuracy.

Julia source scripts that generated these animations are linked under each case.

Case 1 — RK4, \(y' = 1 - t\sqrt[3]{y}\), \(y(0)=1\), \(n=20\) steps

Behavior: The solution starts at \(y(0)=1\) and the right-hand side \(f(t,y)=1-t\sqrt[3]{y}\) pulls \(y\) toward the fixed curve where \(y=1/t^3\). RK4 tracks this with fourth-order accuracy even with the relatively coarse step size \(h=0.25\).

Julia source

RK4 animation: numerical solution trace builds from left to right for y’ = 1 - t·y^(1/3) with y(0)=1; each frame adds one RK4 step

Derivation Notes (Planned)

Short derivations will be added to explain the core equations and assumptions.

Worked Example (Planned)

A compact numerical example with intermediate steps will be included.

Implementation Notes (Planned)

Implementation details, numerical stability notes, and practical pitfalls will be added.

Legacy Animation Inventory (Stub)

  • Legacy module page: Runge-Kutta Method (ok)
  • Animation links found in module Animations paragraph: 4
  • Unique animation portals: 1

Animation Portals

  1. Runge-Kutta Method of Order 4 (ok)
  • Animation item links found: 1

Animation Items

  1. Runge-Kutta Method (ok)
  • Main animated GIF count: 1
  • http://localhost:8000/a2001/Animations/OrdinaryDE/RungeKutta1/RungeKuttaaa.gif

References

Mathew, John H. 2000-2019. Numerical Analysis - Numerical Methods Modules. https://web.archive.org/web/20190808102217/http://mathfaculty.fullerton.edu/mathews/n2003/NumericalUndergradMod.html.