lab.faris0x.dev

Simplex & Big-M

Move through the tableaus of a linear program and take the worked solution away as . The explanations come from the same trace you see on screen.

Problem

Examples
Maximise Z=\text{Maximise } Z = xx + yy
Subject to
xx + yy

Exact input: 3/43/4, 0.50.5, −2-2. Non-negative variables are assumed.

Reading the tableau

Each row is a constraint in standard form; the b.v. column gives the basic variable for that row. The objective row is written as Z−c′x+Ma=0Z - c'x + M a = 0, so a negative entry identifies a variable that can improve the objective. The pivot cell is outlined.

Conventions

The tool uses the common ZZ-row convention. Choose the entering variable from the most negative objective coefficient, then apply the ratio test; ties go to the lowest row. Minimisation is solved as the maximisation of −C-C, and the reported value is converted back.

Big-M uses a pair a+bMa + bM with M→∞M \to \infty treated as arbitrarily large. Pivot decisions follow the exact coefficients, so the tableau matches a hand calculation.

Export

The tab previews the document and lets you copy or download the .tex source. It usesamsmath and array, so a standard TeX installation compiles it and the preview matches the exported tableaus.