The Gauss-Seidel method is an iterative technique used to solve a system of linear equations. It's particularly useful for large systems where direct methods may be computationally expensive. The method uses the most recent values of the variables as soon as they are available, allowing for potentially faster convergence.
Rearrange the Equations: Solve each equation for one variable in terms of the others.
Initial Guess: Start with an initial guess for the values of the variables (x1,y1,z1)
Iterate: Substitute the known values into the rearranged equations to update the values of the variables.
Convergence Check: Repeat the iteration until the values converge.
Example
Consider the following system of equations:
⎩⎨⎧4x+y+z=12x+5y+2z=272x+y+6z=18
Error Margin is 0.1
1. Rearranging the Equations:
x=412−y−z
y=527−x−2z
z=618−2x−y
2. Initial Guess:
Start with
(x0=0,y0=0,z0=0)
Iterations:
First Iteration:
Calculate x1:
x1=412−0−0=3
Calculate y1:
y1=527−3−0=4.8
Calculate z1:
z1=618−2(3)−4.8=1.2
Second Iteration:
Calculate x2:
x2=412−4.8−1.2≈1.5
Calculate y2:
y2=527−1.5−2(1.2)≈4.62
Calculate z2:
z2=618−2(1.5)−4.62≈1.73
Third Iteration:
Calculate x3:
x3=412−4.62−1.73≈1.41
Calculate y3:
y3=527−1.41−2(1.73)≈4.43
Calculate z3:
z3=618−2(1.41)−4.43≈1.79
Fourth Iteration:
Calculate x4:
x4=412−4.43−1.79≈1.445
Calculate y4:
y4=527−1.445−2(1.79)≈4.395
Calculate z4:
z4=618−2(1.445)−4.395≈1.785
Conclusion
The Gauss-Seidel method is simple to implement and can be very effective for certain types of systems. Its performance depends on the properties of the coefficient matrix; specifically, it works best when the matrix is diagonally dominant.