CSC 445/545 Notes 1.3: Two Phase Example

*************** Problem     1 ***************
Phase 1: Input dictionary.
X3 =  -3.00+   1.00 X1 +   1.00 X2 
X4 =   2.00-   3.00 X1 +   4.00 X2 
-----------------------------------------------
z  =  -0.00+   1.00 X1 +   1.00 X2 

Phase 1: Before pivoting to make feasible.
X3 =  -3.00+   1.00 X1 +   1.00 X2 +   1.00 X5 
X4 =   2.00-   3.00 X1 +   4.00 X2 +   1.00 X5 
-----------------------------------------------
z  =  -0.00+   0.00 X1 +   0.00 X2 -   1.00 X5 

X5  enters.   X3  leaves.  z = -0.000000 
The initial dictionary:
X5 =   3.00-   1.00 X1 -   1.00 X2 +   1.00 X3 
X4 =   5.00-   4.00 X1 +   3.00 X2 +   1.00 X3 
-----------------------------------------------
z  =  -3.00+   1.00 X1 +   1.00 X2 -   1.00 X3 

X1  enters.   X4  leaves.  z = -3.000000 

After   1 pivot:
X5 =   1.75-   1.75 X2 +   0.75 X3 +   0.25 X4 
X1 =   1.25+   0.75 X2 +   0.25 X3 -   0.25 X4 
-----------------------------------------------
z  =  -1.75+   1.75 X2 -   0.75 X3 -   0.25 X4 

X2  enters.   X5  leaves.  z = -1.750000 

After   2 pivots:
X2 =   1.00+   0.43 X3 +   0.14 X4 -   0.57 X5 
X1 =   2.00+   0.57 X3 -   0.14 X4 -   0.43 X5 
-----------------------------------------------
z  =  -0.00+   0.00 X3 +   0.00 X4 -   1.00 X5 

The optimal solution: -0.000000
X1  =     2.0000   X2  =     1.0000   X3  =     0.0000   X4  =     0.0000   


The initial dictionary:
X2 =   1.00+   0.43 X3 +   0.14 X4 
X1 =   2.00+   0.57 X3 -   0.14 X4 
-----------------------------------------------
z  =   3.00+   1.00 X3 +   0.00 X4 

The problem is UNBOUNDED.