Function Rand(0,1)

[edward77]

Richard, I have a strong suspicion that Rand(0,1) does not work but maybe I am doing something wrong elsewhere. I'm creating an alternative Yamazaki scenario in which there are two possible attack plans for the AI Akechi where Rand(0,1) decides which one is selected either defensive or all out attack. I firstly used 1 as the all out attack and for five successive runs it was never selected. I then swapped the options with 0 being the all out attack option. Again I had five successive runs all of which were all out attack. In total that is 10 successive selections of 0. The probability of this is (1/2)^10. Here is the code where the offender is b which is always 0. Similarly a is also always 0:-

// Scenario-specific AI code goes here - you can look at some of the historical scenarios for examples.

int turn;
int team:
int id:
int i;
int j;
int v;
int a;
int b;
int visibility;
turn = GetTurn();


if ((turn == 0) || (turn == 1))
{
visibility = 25;
}

if ((turn == 2) || (turn == 3))
{
visibility = 45;
}

if ((turn == 4) || (turn == 5))
{
visibility = 75;
}

if (turn > 5)
{
visibility = 110;
}

if (turn > 7)
{
visibility = 180;
}

for (j = 0; j < 2; j++)
{
for (i = 0; i < GetUnitCount(j); i++)
{
id = GetUnitID(j,i);
if (id != -1)
{
v = visibility;
// Increase visibility for units on heights
// if (GetTileHeight(GetUnitX(id), GetUnitY(id)) >= 50)
// {
// v += 10;
// }
SetAttrib(id, "LOS", v);
}
}
}

if (turn == 0)
{
AddVizCamCenter (56, 56); // Shoryuji Castle
AddVizFunctionCall("ShowUIScreen","BattlePop0", "Anim1","IDS_SCENARIO_YAMAZAKI_1582");
AddVizDelay(15);
AddVizCamCenter (38, 46); // Enmyojigawa
AddVizFunctionCall("ShowUIScreen","BattlePop0", "Anim1","IDS_SCENARIO_YAMAZAKI_1582_8");
AddVizDelay(15);
AddVizCamCenter (37, 28); // Tennozan
AddVizFunctionCall("ShowUIScreen","BattlePop0", "Anim1","IDS_SCENARIO_YAMAZAKI_1582_2");
AddVizDelay(15);
AddVizCamCenter (22, 33); // Yamazaki
AddVizFunctionCall("ShowUIScreen","BattlePop0", "Anim1","IDS_SCENARIO_YAMAZAKI_1582_3");
AddVizDelay(15);
AddVizCamCenter (31, 21); // Forest 1
AddVizFunctionCall("ShowUIScreen","BattlePop0", "Anim1","IDS_SCENARIO_YAMAZAKI_1582_4");
AddVizDelay(15);
AddVizCamCenter (45, 20); // Forest 2
AddVizFunctionCall("ShowUIScreen","BattlePop0", "Anim1","IDS_SCENARIO_YAMAZAKI_1582_5");
AddVizDelay(15);
AddVizCamCenter (59, 19); // Forest 3
AddVizFunctionCall("ShowUIScreen","BattlePop0", "Anim1","IDS_SCENARIO_YAMAZAKI_1582_6");
AddVizDelay(15);
AddVizCamCenter (22, 33);
a = Rand(0,1);
b = Rand(0,1);
}

if (turn == 1)
{
MoveTeamCoord( 1, 2, 27, 49, 24);
MoveTeamCoord( 1, 3, 29, 43, 24);
MoveTeamCoord( 1, 4, 31, 41, 24);
MoveTeamCoord( 1, 5, 34, 39, 24);
MoveTeamCoord( 1, 6, 37, 38, 24);
MoveTeamCoord( 1, 7, 32, 44, 24);
}

if ((turn == 1) & (a == 1))
{
MoveTeamCoord( 1, 0, -1, -1, 64);
}

if ((turn == 1) & (b == 0))
{
MoveTeamCoord( 1, 2, -1, -1, 16);
MoveTeamCoord( 1, 3, -1, -1, 16);
MoveTeamCoord( 1, 4, -1, -1, 16);
MoveTeamCoord( 1, 5, -1, -1, 16);
MoveTeamCoord( 1, 6, -1, -1, 16);
MoveTeamCoord( 1, 7, -1, -1, 16);
}

if ((turn == 3) & (b == 0))
{
AddVizCamCenter (38, 46); // All out attack
AddVizFunctionCall("ShowUIScreen","BattlePop0", "Anim1","IDS_SCENARIO_YAMAZAKI_1582_9");
AddVizDelay(15);
}

if (turn == 9)
{
AddVizCamCenter (40, 61); // Hosokawa Reinforce
AddVizFunctionCall("ShowUIScreen","BattlePop0", "Anim1","IDS_SCENARIO_YAMAZAKI_1582_7");
AddVizDelay(15);
MoveTeamCoord( 1, 1, 45, 40, 24);
}

[rbodleyscott]

This is an error in your code logic, not a problem with Rand(0,1).

a and b are local variables, so they are not stored anywhere when the program leaves the function.

You set them using Rand(0,1) on turn 0, and then when the function is called on turn 1 they have been created anew with the default value of 0.

You need to use a variable that won't get reset.

in ARCHON (FOG2) you could use a global variable, but in STUB (SJ and P&S) I suggest using a UniversalVariable:

e.g.
if (turn == 0)
{
...
...
SetUniversalVar("RandomPlanA", Rand(0,1));
SetUniversalVar("RandomPlanB", Rand(0,1));
}

if ((turn == 1) & (GetUniversalVar("RandomPlanA") == 1))
{
MoveTeamCoord( 1, 0, -1, -1, 64);
}

[edward77]

Oh right. Thank you for that.