Re: Non-repeating Random Numbers
This WebDNA talk-list message is from 2002
It keeps the original formatting.
numero = 43036
interpreted = N
texte = Dan Strong wrote: > Generate 6 random numbers between 1 and 54: > > How do I simply and elegantly ensure that all six numbers are different? > By simply and elegantly I mean without resorting to any temp .dbs or > anything like that. >
That's not random, though. A true random number sequence can contain a very large run of identical values. What I think you want is to chose 6 unique values from between 1 and 54. Why don't you store the result in a text variable and check to see if the value you are looking for is already there? Remember to use a delimeter around each value so you don't match substrings. Something like this (NOT TESTED):[text]numbers=+[text] [math]found=0[/math] [loop start=1&end=20] [text]number=[math]ceil([RANDOM format=float]*(54))[/math][/text] [showif [numbers]!+[number]+] [text]numbers=[numbers]+[number]+[/text] [math]found=[found]+1[/math] [/showif] [showif [found]=6][break][/showif] [/loop]then your [numbers] text variable contains all 6 unique values. Be aware that PRND's for most computers are really lousy.John-- John Peacock Director of Information Research and Technology Rowman & Littlefield Publishing Group 4720 Boston Way Lanham, MD 20706 301-459-3366 x.5010 fax 301-429-5747 ------------------------------------------------------------- This message is sent to you because you are subscribed to the mailing list . To unsubscribe, E-mail to: To switch to the DIGEST mode, E-mail to Web Archive of this list is at: http://search.smithmicro.com/
Associated Messages, from the most recent to the oldest:
Dan Strong wrote: > Generate 6 random numbers between 1 and 54: > > How do I simply and elegantly ensure that all six numbers are different? > By simply and elegantly I mean without resorting to any temp .dbs or > anything like that. > That's not random, though. A true random number sequence can contain a very large run of identical values. What I think you want is to chose 6 unique values from between 1 and 54. Why don't you store the result in a text variable and check to see if the value you are looking for is already there? Remember to use a delimeter around each value so you don't match substrings. Something like this (NOT TESTED):[text]numbers=+[text] [math]found=0[/math] [loop start=1&end=20] [text]number=[math]ceil([RANDOM format=float]*(54))[/math][/text] [showif [numbers]!+[number]+] [text]numbers=[numbers]+[number]+[/text] [math]found=[found]+1[/math] [/showif] [showif [found]=6][break][/showif] [/loop]then your [numbers] text variable contains all 6 unique values. Be aware that PRND's for most computers are really lousy.John-- John Peacock Director of Information Research and Technology Rowman & Littlefield Publishing Group 4720 Boston Way Lanham, MD 20706 301-459-3366 x.5010 fax 301-429-5747 ------------------------------------------------------------- This message is sent to you because you are subscribed to the mailing list . To unsubscribe, E-mail to: To switch to the DIGEST mode, E-mail to Web Archive of this list is at: http://search.smithmicro.com/
John Peacock
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