Rand - Revision history

Sandman: /* Definition */

2008-05-09T10:24:57Z

Definition

←Older revision		Revision as of 10:24, 9 May 2008
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	Returns a random number, ranging from a certain lower limit to a certain upper limit. The limits are within the range.		Returns a random number, ranging from a certain lower limit to a certain upper limit. The limits are within the range.

-	Make sure the difference between ''lowerlimit'' and ''upperlimit'' does not exceed 32767 (2^15). If that is needed, the function ''rand2()'' below can be used.	+	Make sure the difference between ''lowerlimit'' and ''upperlimit'' does not exceed 32767 (2^15-1). If that is needed, the function ''rand2()'' below can be used.

	== Parameters ==		== Parameters ==

Sandman at 16:03, 1 March 2008

2008-03-01T16:03:29Z

←Older revision		Revision as of 16:03, 1 March 2008
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	Returns a random number, ranging from a certain lower limit to a certain upper limit. The limits are within the range.		Returns a random number, ranging from a certain lower limit to a certain upper limit. The limits are within the range.

-	Make sure the difference between ''lowerlimit'' and ''upperlimit'' does not exceed 32767 (2^15).	+	Make sure the difference between ''lowerlimit'' and ''upperlimit'' does not exceed 32767 (2^15). If that is needed, the function ''rand2()'' below can be used.

	== Parameters ==		== Parameters ==
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	</pre>		</pre>
	To understand this code, one can read [http://www.azillionmonkeys.com/qed/random.html its source].		To understand this code, one can read [http://www.azillionmonkeys.com/qed/random.html its source].
		+
		+	{{Funcbox
		+	\| category = Math
		+	}}

Sandman at 03:42, 10 January 2008

2008-01-10T03:42:15Z

←Older revision		Revision as of 03:42, 10 January 2008
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	== Notes ==		== Notes ==
	To synchronize rand() on different computers, the function [[rand_seed]]() can be used.		To synchronize rand() on different computers, the function [[rand_seed]]() can be used.
		+
		+	Rand() is not a very good function on itself. To counter this, the following ''rand2()'' can be used:
		+	<pre>
		+	#define RAND_MAX 32767
		+	#define DRAND_RANGE (1.0/((RAND_MAX + 1)*(RAND_MAX + 1)))
		+	#define irand(x) ((unsigned int) ((x) * drand ()))
		+	Function float drand ()
		+	Private
		+	float f;
		+	Begin
		+	Repeat
		+	f = (rand (0,RAND_MAX) * (RAND_MAX + 1.0)
		+	+ rand (0,RAND_MAX)) * DRAND_RANGE;
		+	Until (f < 1); /* Round off */
		+	return f;
		+	End
		+	Function int rand2(int lowerlimit, int upperlimit)
		+	Begin
		+	return (lowerlimit+irand(upperlimit-lowerlimit+1));
		+	End
		+	</pre>
		+	To understand this code, one can read [http://www.azillionmonkeys.com/qed/random.html its source].

Sandman at 03:04, 10 January 2008

2008-01-10T03:04:00Z

←Older revision		Revision as of 03:04, 10 January 2008
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	Returns a random number, ranging from a certain lower limit to a certain upper limit. The limits are within the range.		Returns a random number, ranging from a certain lower limit to a certain upper limit. The limits are within the range.
		+
		+	Make sure the difference between ''lowerlimit'' and ''upperlimit'' does not exceed 32767 (2^15).

	== Parameters ==		== Parameters ==

Sandman at 23:23, 8 July 2007

2007-07-08T23:23:13Z

New page

[[Category:functions]]
[[Category:math]]

==Definition==
'''INT''' rand ( <'''INT''' lowerlimit> , <'''INT''' upperlimit> )

Returns a random number, ranging from a certain lower limit to a certain upper limit. The limits are within the range.

== Parameters ==
{|
| '''INT''' lowerlimit || - The lower limit for the random value.
|-
| '''INT''' upperlimit|| - The upper limit for the random value.
|}

== Returns ==
'''INT''' : A random value: lowerlimit <= result <= upperlimit

== Notes ==
To synchronize rand() on different computers, the function [[rand_seed]]() can be used.