src/HOL/Matrix_LP/CplexMatrixConverter.ML
changeset 46988 9f492f5b0cec
parent 46531 eff798e48efc
child 47455 26315a545e26
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/HOL/Matrix_LP/CplexMatrixConverter.ML	Sat Mar 17 12:52:40 2012 +0100
@@ -0,0 +1,128 @@
+(*  Title:      HOL/Matrix/CplexMatrixConverter.ML
+    Author:     Steven Obua
+*)
+
+signature MATRIX_BUILDER =
+sig
+    type vector
+    type matrix
+    
+    val empty_vector : vector
+    val empty_matrix : matrix
+
+    exception Nat_expected of int
+    val set_elem : vector -> int -> string -> vector
+    val set_vector : matrix -> int -> vector -> matrix
+end;
+
+signature CPLEX_MATRIX_CONVERTER = 
+sig
+    structure cplex : CPLEX
+    structure matrix_builder : MATRIX_BUILDER 
+    type vector = matrix_builder.vector
+    type matrix = matrix_builder.matrix
+    type naming = int * (int -> string) * (string -> int)
+    
+    exception Converter of string
+
+    (* program must fulfill is_normed_cplexProg and must be an element of the image of elim_nonfree_bounds *)
+    (* convert_prog maximize c A b naming *)
+    val convert_prog : cplex.cplexProg -> bool * vector * matrix * vector * naming
+
+    (* results must be optimal, converts_results returns the optimal value as string and the solution as vector *)
+    (* convert_results results name2index *)
+    val convert_results : cplex.cplexResult -> (string -> int) -> string * vector
+end;
+
+functor MAKE_CPLEX_MATRIX_CONVERTER (structure cplex: CPLEX and matrix_builder: MATRIX_BUILDER) : CPLEX_MATRIX_CONVERTER =
+struct
+
+structure cplex = cplex
+structure matrix_builder = matrix_builder
+type matrix = matrix_builder.matrix
+type vector = matrix_builder.vector
+type naming = int * (int -> string) * (string -> int)
+
+open matrix_builder 
+open cplex
+
+exception Converter of string;
+
+fun neg_term (cplexNeg t) = t
+  | neg_term (cplexSum ts) = cplexSum (map neg_term ts)
+  | neg_term t = cplexNeg t 
+
+fun convert_prog (cplexProg (_, goal, constrs, bounds)) = 
+    let        
+        fun build_naming index i2s s2i [] = (index, i2s, s2i)
+          | build_naming index i2s s2i (cplexBounds (cplexNeg cplexInf, cplexLeq, cplexVar v, cplexLeq, cplexInf)::bounds)
+            = build_naming (index+1) (Inttab.update (index, v) i2s) (Symtab.update_new (v, index) s2i) bounds
+          | build_naming _ _ _ _ = raise (Converter "nonfree bound")
+
+        val (varcount, i2s_tab, s2i_tab) = build_naming 0 Inttab.empty Symtab.empty bounds
+
+        fun i2s i = case Inttab.lookup i2s_tab i of NONE => raise (Converter "index not found")
+                                                     | SOME n => n
+        fun s2i s = case Symtab.lookup s2i_tab s of NONE => raise (Converter ("name not found: "^s))
+                                                     | SOME i => i
+        fun num2str positive (cplexNeg t) = num2str (not positive) t
+          | num2str positive (cplexNum num) = if positive then num else "-"^num                        
+          | num2str _ _ = raise (Converter "term is not a (possibly signed) number")
+
+        fun setprod vec positive (cplexNeg t) = setprod vec (not positive) t  
+          | setprod vec positive (cplexVar v) = set_elem vec (s2i v) (if positive then "1" else "-1")
+          | setprod vec positive (cplexProd (cplexNum num, cplexVar v)) = 
+            set_elem vec (s2i v) (if positive then num else "-"^num)
+          | setprod _ _ _ = raise (Converter "term is not a normed product")        
+
+        fun sum2vec (cplexSum ts) = fold (fn t => fn vec => setprod vec true t) ts empty_vector
+          | sum2vec t = setprod empty_vector true t                                                
+
+        fun constrs2Ab j A b [] = (A, b)
+          | constrs2Ab j A b ((_, cplexConstr (cplexLeq, (t1,t2)))::cs) = 
+            constrs2Ab (j+1) (set_vector A j (sum2vec t1)) (set_elem b j (num2str true t2)) cs
+          | constrs2Ab j A b ((_, cplexConstr (cplexGeq, (t1,t2)))::cs) = 
+            constrs2Ab (j+1) (set_vector A j (sum2vec (neg_term t1))) (set_elem b j (num2str true (neg_term t2))) cs
+          | constrs2Ab j A b ((_, cplexConstr (cplexEq, (t1,t2)))::cs) =
+            constrs2Ab j A b ((NONE, cplexConstr (cplexLeq, (t1,t2)))::
+                              (NONE, cplexConstr (cplexGeq, (t1, t2)))::cs)
+          | constrs2Ab _ _ _ _ = raise (Converter "no strict constraints allowed")
+
+        val (A, b) = constrs2Ab 0 empty_matrix empty_vector constrs
+                                                                 
+        val (goal_maximize, goal_term) = 
+            case goal of
+                (cplexMaximize t) => (true, t)
+              | (cplexMinimize t) => (false, t)                                     
+    in          
+        (goal_maximize, sum2vec goal_term, A, b, (varcount, i2s, s2i))
+    end
+
+fun convert_results (cplex.Optimal (opt, entries)) name2index =
+    let
+        fun setv (name, value) v = matrix_builder.set_elem v (name2index name) value
+    in
+        (opt, fold setv entries (matrix_builder.empty_vector))
+    end
+  | convert_results _ _ = raise (Converter "No optimal result")
+
+end;
+
+structure SimpleMatrixBuilder : MATRIX_BUILDER = 
+struct
+type vector = (int * string) list
+type matrix = (int * vector) list
+
+val empty_matrix = []
+val empty_vector = []
+
+exception Nat_expected of int;
+
+fun set_elem v i s = v @ [(i, s)] 
+
+fun set_vector m i v = m @ [(i, v)]
+
+end;
+
+structure SimpleCplexMatrixConverter =
+  MAKE_CPLEX_MATRIX_CONVERTER(structure cplex = Cplex and matrix_builder = SimpleMatrixBuilder);