/* Returns a sample from Gamma(a, 1).
*/
double GammaRand(double a)
{
/* Algorithm:
* G. Marsaglia and W.W. Tsang, A simple method for generating gamma
* variables, ACM Transactions on Mathematical Software, Vol. 26, No. 3,
* Pages 363-372, September, 2000.
* http://portal.acm.org/citation.cfm?id=358414
*/
double boost, d, c, v;
if(a < 1) {
/* boost using Marsaglia's (1961) method: gam(a) = gam(a+1)*U^(1/a) */
boost = exp(log(Rand())/a);
a++;
}
else boost = 1;
d = a-1.0/3; c = 1.0/sqrt(9*d);
while(1) {
double x,u;
do {
x = RandN();
v = 1+c*x;
} while(v <= 0);
v = v*v*v;
x = x*x;
u = Rand();
if((u < 1-.0331*x*x) ||
(log(u) < 0.5*x + d*(1-v+log(v)))) break;
}
return( boost*d*v );
}
void CreateDamageExplosion (int h, int i)
{
if (EGI_FLAG (bDamageExplosions, 1, 0, 0) &&
(gameStates.app.nSDLTicks - gameData.smoke.objExplTime [i] > 100)) {
gameData.smoke.objExplTime [i] = gameStates.app.nSDLTicks;
if (!RandN (11 - h))
CreateSmallFireballOnObject (OBJECTS + i, F1_0, 1);
}
}
void CreateDamageExplosion (int h, int i)
{
if (EGI_FLAG (bDamageExplosions, 1, 0, 0) &&
(gameStates.app.nSDLTicks - *particleManager.ObjExplTime (i) > 100)) {
*particleManager.ObjExplTime (i) = gameStates.app.nSDLTicks;
if (!RandN (11 - h))
CreateSmallFireballOnObject (OBJECTS + i, I2X (1), 1);
}
}
void MATRIX::Mutate(double mutationProbability, double min, double max) {
for (int i=0;i<length;i++)
for (int j=0;j<width;j++) {
// if ( Rand(0,1) < mutationProbability ) {
double randN = mutationProbability * (max-min) * RandN();
Add(i,j,randN);
if ( Get(i,j)<min )
Set(i,j,min);
if ( Get(i,j)>max )
Set(i,j,max);
//Set(i,j, Rand(min,max) );
// }
}
}
