E-CodeODE solver: Euler vs RK4 with a table — a TI-84 Plus CE program
ODESOLV is a TI-BASIC program for the TI-84 Plus CE. Type y'=f(X,Y), the start point, the end X and the number of steps: prints an RK4 table, then Euler vs RK4 at the end, and reruns RK4 with twice the steps for an error estimate.
What it asks for and what it shows
It asks for 5 values at its prompts. In the example below it shows X END, EUL, RK4, RK2N, ERR, EERR.
Example run
One of its oracle test cases: “y'=y, e^1 in 10 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 | 10 |
| The screen shows | |
X END= | 1 |
EUL= | 2.59374246 |
RK4= | 2.718279744 |
RK2N= | 2.718281693 |
ERR= | 1.299014113E-7 |
EERR= | 0.1245392326 |
How it's checked
7 test cases, each checked against an independent method. Replayed key by key on a virtual TI-84 Plus CE, they make 46 checks.
How E-Code checks every program
Run it or put it on your calculator
- Open the library in the TI-84 Plus CE calculator and pick “ODE solver: Euler vs RK4 with a table” (ODESOLV).
- Put it on your own calculator with a computer and a USB cable, or type it in by hand.
Related programs
- Newton's method with an iteration table
- Quadratic formula solver
- Circle area and circumference
- Newton-Raphson root finder
- Bisection root finder
All TI-84 Plus CE math programs · All TI-84 Plus CE programs