Sunday, February 20, 2011

Solving System of Equations using Gauss Elimination Method (Part 4)

After you download an excel program Gauss Elimination Method from our web site and open it, you'll find the following screen.


You have to click "Options..." and "Enable this content" to enable the VBA otherwise the VBA code will be blocked and can't run the program.

The program will show a form asking for your agreement confirmation.


After you've agreed, you'll find the main screen, then click Start.


You'll find the menu whether you need to review or recalculate the previous equations or you want to add new equations. Let's try review the earlier equations by clicking at "Existing equations" button.


The program will move to another screen where you can change values in matrix [A] or vector {B} and recalculation to solve the equations with the same number of equations. For this example, the dimension of matrix [A] is 3x3. So if you want to solve another set of linear equations with 3 unknowns then you can modify this existing table or you can either create new table which we will explain later.


In this screen, you will be able to change values only in matrix [A] and vector {B}. Other cells are locked. The program will show the values of solution vector {X} as soon as the calculation is complete.

Now, let's test the case of "division by zero" that we explained in [Solving System of Equations using Gauss Elimination Method (Part 3)] by swapping equation (1) and (3) as follows then click "Solve" button. The screen will show the same result in solution vector {X}.


Let's try to change equations and click "Solve". If there's nothing wrong with equations, you'll find solutions.


In case something wrong with equations, the program will shows the error message. The following equations have no solution and program terminated automatically.


Let's see how to setup the program to solve more equations such as 10 unknowns in the next post.

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