DRAND48(3C)

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DRAND48(3C)

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drand48, erand48, lrand48, nrand48, mrand48, jrand48, srand48, seed48, lcong48 - ��

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	double drand48 ( )
	
	double erand48 (xsubi)
	unsigned short xsubi [3];
	
	long lrand48 ( )
	
	long nrand48 (xsubi)
	unsigned short xsubi [3];
	
	long mrand48 ( )
	
	long jrand48 (xsubi)
	unsigned short xsubi [3];
	
	void srand48 (seedval)
	long seedval;
	
	unsigned short *seed48 (seed16v)
	unsigned short seed16v [3];
	
	void lcong48 (param)
	unsigned short param [7];

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�� 48-�� .

�� drand48 � erand48 �� , �� [0.0, 1.0).

�� lrand48 � nrand48 �� long, �� [0, 2^31).

�� mrand48 � jrand48 �� , �� long, �� [-2^31, 2^31).

�� srand48, seed48 � lcong48 �� , �� -�� drand48, lrand48, mrand48. (�� , � �� , �� drand48, lrand48, mrand48 �� , �� , �� , �� .) �� erand48, nrand48 � jrand48 �� .

�� , �� 48-�� X [i] � ��

	X [n+1] = (a * X [n] + c) mod m           n   0

�� m = 2^48 � �� 48-�� . �� lcong48, �� a � �� c �� :

	a = 0x5DEECE66D = 0273673163155
	c = 0xB = 013

�� drand48, erand48, lrand48, nrand48, mrand48 �� jrand48 �� 48 �� X[i]. �� , �� , �� .

�� drand48, lrand48 � mrand48 �� 48-�� X[i] �� - �� . �� erand48, nrand48 � jrand48 �� X[i], �� . �� ; �� X[i] � �� 16-�� . �� erand48, nrand48 � jrand48 �� ; �� , �� , �� .

�� srand48 �� 32 �� X[i] �� 32-� �� . �� , �� 16 �� X[i] �� 0x330E.

�� seed48 �� 48 �� X[i] �� - �� 16-�� . �� X[i] �� 48-�� , �� seed48. �� seed48 �� . �� , �� . �� , �� , �� X[i], �� , �� , �� seed48.

�� lcong48 �� X [i], �� a � �� c. � ��, �� , �� param [0-2] �� X [i], �� param [3-5] - �� a �, ��, param [6] - 16-�� c. �� lcong48 �� "��" �� a � �� c, �� , �� srand48 �� seed48.

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�� , �� . � �� drand48 � erand48 �� ; �� :

	long irand48 (m)
	unsigned short m;
	
	long krand48 (xsubi, m)
	unsigned short xsubi [3], m;

�� irand48 � krand48 �� long, �� [0, m-1].