# Returns Index of a pre-assigned Probability-Option

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This is kinda hard to explain for a non-native speaker, but I'll try anyway; maybe someone can use this Function, too. Say, you're programming an RPG-Game and you repeatedly want to check, whether certain events with different probabilites are about to happen. For example, you'll want to create a couple of Unique, Rare and Common Items, and that certain Unique Sword of Fate should occur much more scarcely then a common Famer's Shovel. Of course. Now this neat little Function can be assigned certain fields of probabilites (a maximum of 10), then it rolls a dice within the range of 1 and all added fields, and finally returns the index, in which field the number occured. The Function can return a maximum of 10 Index-Numbers. Dim z_chance(10) ;Maximum of Probabilty-Fields Dim iReturn(10) ; Maximum of returned Numbers ; Initialize a 33% Chance, returns one Number: Perchance(20,20,20,0,0,0,0,0,0,0,1) ; Initialize a 10 / 20 / 30 / 40% Chance, returns one Number: Perchance(1,2,3,4,0,0,0,0,0,0,1) ; Initialize a 0.1 / 5 / 10% Chance (Remainder 84.9%), returns 4 Numbers: Perchance(1,50,100,849,0,0,0,0,0,0,4) Function Perchance(z_chance1,z_chance2,z_chance3,z_chance4,z_chance5,z_chance6,z_chance7,z_chance8,z_chance9,z_chance10,z_nr) Local zMax = 0 Local z0 Local zDice Local zAdd z_chance(1) = z_chance1 z_chance(2) = z_chance2 z_chance(3) = z_chance3 z_chance(4) = z_chance4 z_chance(5) = z_chance5 z_chance(6) = z_chance6 z_chance(7) = z_chance7 z_chance(8) = z_chance8 z_chance(9) = z_chance9 z_chance(10) = z_chance10 For a = 1 to z_nr iReturn(a) = 0 Next z0 = 11 For a = 1 To 10 If z_chance(a) > 0 zMax = zMax + z_chance(a) Else z0 = a EndIf Next For nr = 1 To z_nr zDice = Rand(1,zMax) zAdd = 0 For a = 1 To (z0-1) zAdd = zAdd + z_chance(a) If zAdd >= zDice And iReturn(nr) = 0 iReturn(nr) = a EndIf Next Next End Function |