# Gauß Demonstration

On this page you find a small Java application to demonstrates the steps of the Gauß algorithm. It can also be used to solve linear problems with the simplex algorithm.

The following is a short introduction.

• It is possible to read matrices from files, or enter them directly (see below for the format).
• Display or input of numbers in floating point format or in fractional format.
• A matrix element equal to 0 is suppressed by default.
• Choose a pivot element with the left mouse button.
• In the pivot column right, click on any element to make that element 0 by adding a multiple of the pivot line to this line.
• Right click on the pivot element to make it to 1 by dividing the pivot line through this element.
• Exchange columns by dragging the variable name or the pivot element.
• Exchange lines by dragging the pivot element.
• It is possible to protect the last column or the last line.
• Ctrl-Z to take back all steps.

Here is an example for a final tableau.

The input format is very simple.

• Empty lines or lines starting with ; are not parsed.
• The first line contains the strings with the variable names.
• The following lines contain the rows of the matrix.
• Short lines are filled with 0.
• Missing variables are empty strings.
• Use either floating point or fractional format.

Example:

; Maximize x+3y under the conditins
; x+y <= 4, x+2y <= 5, y <= 2
; Thus we get the equations
; x+y+s1=4, x+2y+s2=5, y+s3=2
;
x y s1 s2 s3
1 1 1 0 0 4
1 2 0 1 0 5
0 1 0 0 1 2
1 3

Download the program as a zipped archive. Extract all files, and start the program by double clicking on "gausser.jar". The source is available. The program may be published elsewhere only with my permission.