(* The Double(Common Outcry) Auction: Zero Intelligent Traders *)



history1 = {{0, 7, 2.06}, {2, 0, 4.940000000000001}, {4, 0, 2.75}, {0, 3, 2.35},

    {4, 1, 2.75}, {0, 3, 2.6}, {1, 0, 5.8}, {0, 4, 2.8}}



candidate1 = Join[history1, {{0, 4, 2.4}}]

message[candidate1]

candidate2 = Join[history1, {{0, 5, 3.4}}]

message[candidate2]



candidate3 = Join[history1, {{3, 0, 4.0}}]

message[candidate3]

candidate4 = Join[history1, {{1, 0, 2.3}}]

message[candidate4]



zitbuy[v_] := Random[Real, {0, v}]

zitbuy[3]



zitsell[c_] := Random[Real, {c, 12}]

zitsell[4]

bidoffer[values_, costs_] := Module[{d1},

    d1 = Random[Integer, {1, Length[values] + Length[costs]}];

    k = If[d1 <= Length[values], {0, d1, zitbuy[values[[d1]]]},

        {d1 - Length[values], 0, zitsell[costs[[d1 - Length[values]]]]}];

    Return[k]]

values = {5, 4, 3, 2, 1}; costs = {2, 7, 8, 9};

hist = {{1, 0, 12}, {0, 2, 0}}



newhist = Join[hist, {bidoffer[values, costs]}]

message[newhist]

histor[1] = hist = {{1, 0, 12}, {0, 2, 0}}



histor[t_] := histor[t] = message[Join

        [histor[t - 1], {bidoffer[values, costs]}]]

histor[2]

hist = Table[histor[j], {j, 2, 800}];



trade = Function[x, ! x[[1]] == 0 && ! x[[2]] == 0]

Select[hist[[799]], trade]