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asp_web_howto thread: Rnd
Message #1 by "O'Hara, Elliott M" <EMOHARA@k...> on Thu, 22 Mar 2001 12:26:31 -0500
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So I want to generate four UNIQUE rnd numbers and put them in an array.
can I seed Rnd to assure that they are indeed unique or do I have to check
the array to see if the next value already exists?
thanks guys
Message #2 by "Wally Burfine" <oopconsultant@h...> on Thu, 22 Mar 2001 21:31:22 -0000
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Elliott,
The random number generator doesn't generate unique numbers, only random
(psudo) numbers. You will have to put them into an array and check the
array. Or put them into a variable string and do an instr on the number.
Regards,
Wally
>From: "O'Hara, Elliott M" <EMOHARA@k...>
>Reply-To: "ASP Web HowTo" <asp_web_howto@p...>
>To: "ASP Web HowTo" <asp_web_howto@p...>
>Subject: [asp_web_howto] Rnd
>Date: Thu, 22 Mar 2001 12:26:31 -0500
>
>So I want to generate four UNIQUE rnd numbers and put them in an array.
>can I seed Rnd to assure that they are indeed unique or do I have to check
>the array to see if the next value already exists?
>thanks guys
>
Message #3 by "Anil Rhemtulla" <AnilR@T...> on Fri, 23 Mar 2001 09:55:30 +0100
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You need to check to ensure new random numbers are in fact unique. However,
as Rnd should produce a 32 bit number, there are over 4 trillion (2 ^ 32)
possible numbers generated. Selecting 4 of these, the chance you get two or
more the same is about 1 in 700 million (you've got about 50x greater chance
of winning the lotto!!).
So in short, yes you should check if it's mission critical - but a fail time
of once out over every 700 million is not too threatening!!
I'm not sure why you need unique random numbers (do they need to be
random?), but perhaps a method such as
for i = 1 to 4
myNum = Round(Rnd() * 1000000) ' Create a random number between 1 and
1 000 000
myNum = myNum * 10 + i ' append the index of the number
to ensure the number is unique (assume index < 10)
next
Cheers,
Anil
Sevina Technologies
www.Sevina.com
----- Original Message -----
From: "O'Hara, Elliott M" <EMOHARA@k...>
To: "ASP Web HowTo" <asp_web_howto@p...>
Sent: Thursday, March 22, 2001 6:26 PM
Subject: [asp_web_howto] Rnd
> So I want to generate four UNIQUE rnd numbers and put them in an array.
> can I seed Rnd to assure that they are indeed unique or do I have to check
> the array to see if the next value already exists?
> thanks guys
Message #4 by "O'Hara, Elliott M" <EMOHARA@k...> on Fri, 23 Mar 2001 06:50:00 -0500
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sorry, left out some very important issues...
I need to generate 4 UNIQUE integers between 1 and 20... the chances of
duplicates is in fact pretty good...
I've sience solved the problem though.. appreciate the response.
-----Original Message-----
From: Anil Rhemtulla [mailto:AnilR@T...]
Sent: Friday, March 23, 2001 3:56 AM
To: ASP Web HowTo
Subject: [asp_web_howto] Re: Rnd
You need to check to ensure new random numbers are in fact unique. However,
as Rnd should produce a 32 bit number, there are over 4 trillion (2 ^ 32)
possible numbers generated. Selecting 4 of these, the chance you get two or
more the same is about 1 in 700 million (you've got about 50x greater chance
of winning the lotto!!).
So in short, yes you should check if it's mission critical - but a fail time
of once out over every 700 million is not too threatening!!
I'm not sure why you need unique random numbers (do they need to be
random?), but perhaps a method such as
for i = 1 to 4
myNum = Round(Rnd() * 1000000) ' Create a random number between 1 and
1 000 000
myNum = myNum * 10 + i ' append the index of the number
to ensure the number is unique (assume index < 10)
next
Cheers,
Anil
Sevina Technologies
www.Sevina.com
----- Original Message -----
From: "O'Hara, Elliott M" <EMOHARA@k...>
To: "ASP Web HowTo" <asp_web_howto@p...>
Sent: Thursday, March 22, 2001 6:26 PM
Subject: [asp_web_howto] Rnd
> So I want to generate four UNIQUE rnd numbers and put them in an array.
> can I seed Rnd to assure that they are indeed unique or do I have to check
> the array to see if the next value already exists?
> thanks guys
Message #5 by "Wally Burfine" <oopconsultant@h...> on Fri, 23 Mar 2001 14:57:12 -0000
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Since the set is very small, why not use 5,10,15 and 19. that way you don't
have to calculate anything
Regards,
Wally
>From: "O'Hara, Elliott M" <EMOHARA@k...>
>Reply-To: "ASP Web HowTo" <asp_web_howto@p...>
>To: "ASP Web HowTo" <asp_web_howto@p...>
>Subject: [asp_web_howto] Re: Rnd
>Date: Fri, 23 Mar 2001 06:50:00 -0500
>
>sorry, left out some very important issues...
>I need to generate 4 UNIQUE integers between 1 and 20... the chances of
>duplicates is in fact pretty good...
>I've sience solved the problem though.. appreciate the response.
>
>-----Original Message-----
>From: Anil Rhemtulla [mailto:AnilR@T...]
>Sent: Friday, March 23, 2001 3:56 AM
>To: ASP Web HowTo
>Subject: [asp_web_howto] Re: Rnd
>
>
>You need to check to ensure new random numbers are in fact unique. However,
>as Rnd should produce a 32 bit number, there are over 4 trillion (2 ^ 32)
>possible numbers generated. Selecting 4 of these, the chance you get two or
>more the same is about 1 in 700 million (you've got about 50x greater
>chance
>of winning the lotto!!).
>
>So in short, yes you should check if it's mission critical - but a fail
>time
>of once out over every 700 million is not too threatening!!
>
>I'm not sure why you need unique random numbers (do they need to be
>random?), but perhaps a method such as
>
>for i = 1 to 4
> myNum = Round(Rnd() * 1000000) ' Create a random number between 1
>and
>1 000 000
> myNum = myNum * 10 + i ' append the index of the
>number
>to ensure the number is unique (assume index < 10)
>next
>
>
>Cheers,
>Anil
>
>Sevina Technologies
>www.Sevina.com
>
>
>----- Original Message -----
>From: "O'Hara, Elliott M" <EMOHARA@k...>
>To: "ASP Web HowTo" <asp_web_howto@p...>
>Sent: Thursday, March 22, 2001 6:26 PM
>Subject: [asp_web_howto] Rnd
>
>
> > So I want to generate four UNIQUE rnd numbers and put them in an array.
> > can I seed Rnd to assure that they are indeed unique or do I have to
>check
> > the array to see if the next value already exists?
> > thanks guys
>
>
Message #6 by "O'Hara, Elliott M" <EMOHARA@k...> on Fri, 23 Mar 2001 10:31:18 -0500
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its for a Process Surviellance team on the Space Shuttle main engine...
I'm making a page that tells them to go observe 4 random tasks...
It has to be random if I use 5,10,15,and 19
the techs at 1,2,3,4 ect... could be planting bombs in the orbitor and i'd
get shot because I never told the Proc Surv. guy to go check them..
:o)
got to be random...
I've got it working now, just couldn't do it in a for next loop..
i did a
this = myrandom
do
that = rnd(blahblahblah)
loop until this<>that
-----Original Message-----
From: Wally Burfine [mailto:oopconsultant@h...]
Sent: Friday, March 23, 2001 9:57 AM
To: ASP Web HowTo
Subject: [asp_web_howto] Re: Rnd
Since the set is very small, why not use 5,10,15 and 19. that way you don't
have to calculate anything
Regards,
Wally
>From: "O'Hara, Elliott M" <EMOHARA@k...>
>Reply-To: "ASP Web HowTo" <asp_web_howto@p...>
>To: "ASP Web HowTo" <asp_web_howto@p...>
>Subject: [asp_web_howto] Re: Rnd
>Date: Fri, 23 Mar 2001 06:50:00 -0500
>
>sorry, left out some very important issues...
>I need to generate 4 UNIQUE integers between 1 and 20... the chances of
>duplicates is in fact pretty good...
>I've sience solved the problem though.. appreciate the response.
>
>-----Original Message-----
>From: Anil Rhemtulla [mailto:AnilR@T...]
>Sent: Friday, March 23, 2001 3:56 AM
>To: ASP Web HowTo
>Subject: [asp_web_howto] Re: Rnd
>
>
>You need to check to ensure new random numbers are in fact unique. However,
>as Rnd should produce a 32 bit number, there are over 4 trillion (2 ^ 32)
>possible numbers generated. Selecting 4 of these, the chance you get two or
>more the same is about 1 in 700 million (you've got about 50x greater
>chance
>of winning the lotto!!).
>
>So in short, yes you should check if it's mission critical - but a fail
>time
>of once out over every 700 million is not too threatening!!
>
>I'm not sure why you need unique random numbers (do they need to be
>random?), but perhaps a method such as
>
>for i = 1 to 4
> myNum = Round(Rnd() * 1000000) ' Create a random number between 1
>and
>1 000 000
> myNum = myNum * 10 + i ' append the index of the
>number
>to ensure the number is unique (assume index < 10)
>next
>
>
>Cheers,
>Anil
>
>Sevina Technologies
>www.Sevina.com
>
>
>----- Original Message -----
>From: "O'Hara, Elliott M" <EMOHARA@k...>
>To: "ASP Web HowTo" <asp_web_howto@p...>
>Sent: Thursday, March 22, 2001 6:26 PM
>Subject: [asp_web_howto] Rnd
>
>
> > So I want to generate four UNIQUE rnd numbers and put them in an array.
> > can I seed Rnd to assure that they are indeed unique or do I have to
>check
> > the array to see if the next value already exists?
> > thanks guys
>
>
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