E-CodeSimplex method with every tableau shown — a TI-84 Plus CE program
SIMPLEX is a TI-BASIC program for the TI-84 Plus CE. Maximize Z=c·x with up to 4 variables and 4 ≤ constraints. It shows the work: the starting tableau, and at each pivot the entering variable (most negative Z-row entry), the ratio test for every row, the leaving variable and the new tableau, then the optimum.
Says so when the problem is unbounded.
What it asks for and what it shows
It asks for 6 values at its prompts. In the example below it shows Z, X1, X2, START TABLEAU, PIVOT 1, ENTER X2 (MOST, R1 NO RATIO, R2 B/A, R3 B/A, LEAVE S2 ROW 2, PIVOT 2, ENTER X1 (MOST, R1 B/A, R2 NO RATIO, R3 B/A, LEAVE S3 ROW 3, OPTIMUM (IN L.
Example run
One of its oracle test cases. The inputs are typed in order, and the results are the values the case expects on the screen.
| Step | Value |
|---|---|
| You enter | |
| Input 1 | 2 |
| Input 2 | 3 |
| Input 3 | {3,5} |
| Input 4 | {1,0,4} |
| Input 5 | {0,2,12} |
| Input 6 | {3,2,18} |
| The screen shows | |
Z= | 36 |
X1= | 2 |
X2= | 6 |
| Text | START TABLEAU |
| Text | PIVOT 1 |
| Text | ENTER X2 (MOST |
| Text | R1 NO RATIO |
R2 B/A= | 6 |
R3 B/A= | 9 |
| Text | LEAVE S2 ROW 2 |
| Text | PIVOT 2 |
| Text | ENTER X1 (MOST |
R1 B/A= | 4 |
| Text | R2 NO RATIO |
R3 B/A= | 2 |
| Text | LEAVE S3 ROW 3 |
| Text | OPTIMUM (IN L |
How it's checked
5 test cases, each checked against an independent method. Replayed key by key on a virtual TI-84 Plus CE, they make 80 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 “Simplex method for linear programming, step by step” (SIMPLEX).
- Put it on your own calculator with a computer and a USB cable, or type it in by hand.
Related programs
- Newton's method for two nonlinear equations, step by step
- Newton-Raphson root finder
- Bisection root finder
- Numerical integration lab
- Newton's method with an iteration table
All TI-84 Plus CE math programs · All TI-84 Plus CE programs