Method next_double

Source/Utils/diamondsquare.hpp:88–113

	}

	double next_double()
	{
		int             j;
		long            k;
		double          temp;

		if (*idum <= 0 || !iy) {
			if (-(*idum) < 1) *idum = 1;
			else *idum = -(*idum);
			for (j = NTAB + 7; j >= 0; j--) {
				k = (*idum) / IQ;
				*idum = IA*(*idum - k*IQ) - IR*k;
				if (*idum < 0) *idum += IM;
				if (j < NTAB) iv[j] = *idum;
			}
			iy = iv[0];
		}
		k = (*idum) / IQ;
		*idum = IA*(*idum - k*IQ) - IR*k;
		if (*idum < 0) *idum += IM;
		j = iy / NDIV;
		iy = iv[j];
		iv[j] = *idum;
		if ((temp = AM*iy) > RNMX) return RNMX;
		else return temp;
	}
};