Examples and get functions

Author: scheinerman

src/SimpleTableaux.jl

@@ -8,11 +8,12 @@ import Base: show
 
 TabEntry = Rational{BigInt}
 
-export DataFrame, Tableau
+export DataFrame, Tableau, get_A, get_b, get_c
+
 """
 Tableau(A::Matrix, b::Vector, c::Vector)
 
-Create a `Tableau` datastructure for the linear program maximize `c'x` subject to `Ax ≤ b`.
+Create a `Tableau` data structure for the linear program maximize `c'x` subject to `Ax ≤ b`.
 """
 struct Tableau
     M::Matrix{TabEntry}   # place to hold the entire Tableau
@@ -32,6 +33,34 @@ struct Tableau
     end
 end
 
+"""
+    get_A(T::Tableau)
+
+Return the coefficient matrix of this `Tableau`.
+"""
+function get_A(T::Tableau)
+    return copy(T.M[1:(T.n_cons), 1:(T.n_vars)])
+end
+
+"""
+    get_b(T::Tableau)
+
+Return the RHS of this `Tableau`.
+"""
+function get_b(T::Tableau)
+    return copy(T.M[1:(T.n_cons), end])
+end
+
+"""
+    get_c(T::Tableau)
+
+Return the objective function of this `Tableau`.
+"""
+function get_c(T::Tableau)
+    c = T.M[end, 1:(T.n_vars)]
+    return collect(-c)
+end
+
 include("Exact.jl")
 include("DataFrame.jl")
 

test/examples.jl

@@ -0,0 +1,25 @@
+using SimpleTableaux
+
+"""
+    example1()
+
+Sample linear program from here: https://www.youtube.com/watch?v=rzRZLGD_aeE
+"""
+function example1()
+    A = [3 5; 4 1]
+    b = [78; 36]
+    c = [5; 4]
+    return Tableau(A, b, c)
+end
+
+"""
+    example2()
+
+Sample linear program from here: https://www.youtube.com/watch?v=rzRZLGD_aeE
+"""
+function example2()
+    A = [3 5 10; 5 2 8; 8 10 3]
+    b = [120; 6; 105]
+    c = [3; 4; 1]
+    return Tableau(A, b, c)
+end