Other Features

Inspection Functions

• basic_vector(T) returns the vector in which the nonbasic variables have been set to zero.
• get_Abc(T) returns the original matrix A and the vectors b and c that were the standard presentation of the linear program.
• get_basis(T) returns the column numbers of the current basis.
• is_feasible(T) returns true if the current basic vector is in the feasible region.
• is_optimal(T) returns true if the tableau has reached an optimal (minimal) state.
• value(T) returns the objective function value of the current basic vector.

Return to start

The function restore! returns the tableau to its state when it was constructed.

julia> T
┌──────────┬───┬─────┬─────┬────────┬─────┬─────────┬──────────┐
│          │ z │ x_1 │ x_2 │    x_3 │ x_4 │     x_5 │      RHS │
│ Obj Func │ 1 │   0 │   0 │ -25/47 │   0 │ -110/47 │ 13500/47 │
├──────────┼───┼─────┼─────┼────────┼─────┼─────────┼──────────┤
│   Cons 1 │ 0 │   1 │   0 │   1/47 │   0 │   -5/47 │   400/47 │
│   Cons 2 │ 0 │   0 │   0 │ -25/47 │   1 │  -16/47 │  -600/47 │
│   Cons 3 │ 0 │   0 │   1 │  -5/47 │   0 │    3/94 │   350/47 │
└──────────┴───┴─────┴─────┴────────┴─────┴─────────┴──────────┘


julia> restore!(T)
┌──────────┬───┬─────┬─────┬─────┬─────┬─────┬─────┐
│          │ z │ x_1 │ x_2 │ x_3 │ x_4 │ x_5 │ RHS │
│ Obj Func │ 1 │ -25 │ -10 │   0 │   0 │   0 │   0 │
├──────────┼───┼─────┼─────┼─────┼─────┼─────┼─────┤
│   Cons 1 │ 0 │   3 │  10 │  -1 │   0 │   0 │ 100 │
│   Cons 2 │ 0 │   5 │   6 │   0 │  -1 │   0 │ 100 │
│   Cons 3 │ 0 │  10 │   2 │   0 │   0 │  -1 │ 100 │
└──────────┴───┴─────┴─────┴─────┴─────┴─────┴─────┘

LaTeX output

Using LatexPrint users can get the code for pasting into a LaTeX document.

julia> using LatexPrint

julia> T
┌──────────┬───┬─────┬─────┬─────┬─────┬──────┬─────┐
│          │ z │ x_1 │ x_2 │ x_3 │ x_4 │  x_5 │ RHS │
│ Obj Func │ 1 │   0 │  -3 │  -2 │   8 │    0 │   9 │
├──────────┼───┼─────┼─────┼─────┼─────┼──────┼─────┤
│   Cons 1 │ 0 │   1 │ 1/2 │   0 │ 9/2 │ -1/2 │ 9/2 │
│   Cons 2 │ 0 │   0 │ 1/2 │  -1 │ 1/2 │  3/2 │ 5/2 │
└──────────┴───┴─────┴─────┴─────┴─────┴──────┴─────┘


julia> lap(T)
\begin{tabular}{|c|ccccc|c|}\hline 
{\Large\strut}$z$ &$x_{1}$ & $x_{2}$ & $x_{3}$ & $x_{4}$ & $x_{5}$ & RHS \\
{\Large\strut}$1$ & $0$ & $-3$ & $-2$ & $8$ & $0$ & $9$\\
\hline 
{\Large\strut}$0$ & $1$ & $\frac{1}{2}$ & $0$ & $\frac{9}{2}$ & $\frac{-1}{2}$ & $\frac{9}{2}$\\
{\Large\strut}$0$ & $0$ & $\frac{1}{2}$ & $-1$ & $\frac{1}{2}$ & $\frac{3}{2}$ & $\frac{5}{2}$\\
\hline 
\end{tabular}

Here is the LaTeX output: