----- Original Message ----- From: "joel boonstra" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Friday, January 16, 2004 4:54 PM Subject: Re: [PHP] odd and even numbers
> Jake, > > > This worked.. somewhat.. here is what I want to do though. > > > > I have two people checking the same email address. I want to break up the > > emails 50/50 to each person. What values can I put into the random number > > generator so that I can get closer to 50/50. I just set up a test page with: > > > > $rand = rand(1, 501); > > > > echo $rand; > > > > if ($rand % 2 == 0) > > echo "even"; > > else > > echo "odd"; > > > > > > and I'm getting a lot more evens than odds, so the one person would get more > > emails than the other. Is there any substitution to rand that I could use to > > get one message to go to one person, then the next to the other? I'd like it > > to be as close to 50/50 as possible. > > Is there any way you can save state? That is, can you keep track of who > got the last one, and use that to determine who should get the next one? > > Otherwise, why not just rand() between 1 and 2? rand(1,2) will, on > average, give you as many 1s as 2s (like flipping a coin). There will > likely be runs of 1 or 2, but over time, doing rand() with two possible > values versus rand() with 501 values will not be significantly > different. > > In fact, since there is one more odd than even between 1 and 501 > (inclusive), you will be getting slightly more odds than evens with that > range than you will with a range of 1 and 2. > > Also, which PHP version are you using? If before 4.2.0, you should seed > the random number generator with srand(). If you are using 4.2.0 or > greater, and still seeing non-random behavior, I don't really have an > answer. > > -- > [ joel boonstra | gospelcom.net ] > > -- > PHP General Mailing List (http://www.php.net/) > To unsubscribe, visit: http://www.php.net/unsub.php > version 4.2.2 Jake -- PHP General Mailing List (http://www.php.net/) To unsubscribe, visit: http://www.php.net/unsub.php
