E-CodeODE: Euler vs RK4 table — a TI-89 Titanium program
ODE89 is a TI-89 BASIC program for the TI-89 Titanium. Type dy/dx = f(x,y), the starting point, the end x and up to 20 steps: a table of the RK4 solution, then Euler and RK4 at the end side by side.
What it asks for and what it shows
It asks for 5 values at its prompts. In the example below it shows EULER, RK4.
Example run
One of its oracle test cases: “y' = y, e in 5 steps”. The inputs are typed in order, and the results are the values the case expects on the screen.
| Step | Value |
|---|---|
| You enter | |
| Input 1 | y |
| Input 2 | 0 |
| Input 3 | 1 |
| Input 4 | 1 |
| Input 5 | 5 |
| The screen shows | |
EULER= | 2.48832 |
RK4= | 2.718251137 |
How it's checked
4 test cases, each checked against an independent method. Replayed key by key on a virtual TI-89 Titanium, they make 15 checks.
How E-Code checks every program
Run it or put it on your calculator
- Open the library in the TI-89 Titanium calculator and pick “ODE: Euler vs RK4 table” (ODE89).
- Put it on your own calculator with a computer and a USB cable, or type it in by hand.
Related programs
- Newton's method on a typed function
- Trapezoid and Simpson vs nInt
- Quadratic roots, exact when possible
- Linear system, exact answers
- Fraction calculator: exact, mixed, decimal
All TI-89 Titanium math programs · All TI-89 Titanium programs