php-general Digest 6 Oct 2008 07:00:18 -0000 Issue 5720
Topics (messages 281451 through 281462):
Re: First 30 characters of a strong
281451 by: Ashley Sheridan
mt_rand() - the same forever?
281452 by: Janek
281453 by: Richard Heyes
281454 by: Janek
281455 by: Ashley Sheridan
281456 by: Janek
281457 by: Jochem Maas
Politics
281458 by: Amy
Re:
281459 by: huaizong wang
Join The Team
281460 by: Hemant Patel
Best Search Algorithm for Millions of record
281461 by: Hemant Patel
281462 by: Micah Gersten
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----------------------------------------------------------------------
--- Begin Message ---
On Sun, 2008-10-05 at 14:52 -0400, Ron Piggott wrote:
> How do I display the first 5 characters of a string?
>
> $string="abcdefghijklmnopqrstuvwxyz";
>
> my desired output is
>
> abcde
>
>
substr($string, 0, 5);
Ash
www.ashleysheridan.co.uk
--- End Message ---
--- Begin Message ---
I wonder whether I can rely on the stability of mt_srand() and
mt_rand(). I want them to generate the same sequence for a fixed seed,
regardless of PHP version. Do you think I can trust it?
Janek
--- End Message ---
--- Begin Message ---
> I wonder whether I can rely on the stability of mt_srand() and
> mt_rand(). I want them to generate the same sequence for a fixed seed,
> regardless of PHP version. Do you think I can trust it?
> Janek
Keep in mind (if you're not already) that mt_rand() doesn't
technically need to be seeded.
--
Richard Heyes
HTML5 Graphing for FF, Chrome, Opera and Safari:
http://www.phpguru.org/RGraph
--- End Message ---
--- Begin Message ---
I know, but I *want* to seed it. My goal is to have a fixed
pseudorandom sequence for each integer (seed) and I don't want those
sequences to change regarding PHP version.
Janek
On Sun, Oct 5, 2008 at 9:52 PM, Richard Heyes <[EMAIL PROTECTED]> wrote:
>> I wonder whether I can rely on the stability of mt_srand() and
>> mt_rand(). I want them to generate the same sequence for a fixed seed,
>> regardless of PHP version. Do you think I can trust it?
>> Janek
>
> Keep in mind (if you're not already) that mt_rand() doesn't
> technically need to be seeded.
>
> --
> Richard Heyes
>
> HTML5 Graphing for FF, Chrome, Opera and Safari:
> http://www.phpguru.org/RGraph
>
--- End Message ---
--- Begin Message ---
On Sun, 2008-10-05 at 21:57 +0200, Janek wrote:
> I know, but I *want* to seed it. My goal is to have a fixed
> pseudorandom sequence for each integer (seed) and I don't want those
> sequences to change regarding PHP version.
>
> Janek
>
> On Sun, Oct 5, 2008 at 9:52 PM, Richard Heyes <[EMAIL PROTECTED]> wrote:
> >> I wonder whether I can rely on the stability of mt_srand() and
> >> mt_rand(). I want them to generate the same sequence for a fixed seed,
> >> regardless of PHP version. Do you think I can trust it?
> >> Janek
> >
> > Keep in mind (if you're not already) that mt_rand() doesn't
> > technically need to be seeded.
> >
> > --
> > Richard Heyes
> >
> > HTML5 Graphing for FF, Chrome, Opera and Safari:
> > http://www.phpguru.org/RGraph
> >
>
Doesn't it also rely on the system clock as well?
Ash
www.ashleysheridan.co.uk
--- End Message ---
--- Begin Message ---
On Sun, Oct 5, 2008 at 10:05 PM, Ashley Sheridan
<[EMAIL PROTECTED]> wrote:
> On Sun, 2008-10-05 at 21:57 +0200, Janek wrote:
>> I know, but I *want* to seed it. My goal is to have a fixed
>> pseudorandom sequence for each integer (seed) and I don't want those
>> sequences to change regarding PHP version.
>>
>> Janek
>>
>> On Sun, Oct 5, 2008 at 9:52 PM, Richard Heyes <[EMAIL PROTECTED]> wrote:
>> >> I wonder whether I can rely on the stability of mt_srand() and
>> >> mt_rand(). I want them to generate the same sequence for a fixed seed,
>> >> regardless of PHP version. Do you think I can trust it?
>> >> Janek
>> >
>> > Keep in mind (if you're not already) that mt_rand() doesn't
>> > technically need to be seeded.
>> >
>> > --
>> > Richard Heyes
>> >
>> > HTML5 Graphing for FF, Chrome, Opera and Safari:
>> > http://www.phpguru.org/RGraph
>> >
>>
> Doesn't it also rely on the system clock as well?
>
>
> Ash
> www.ashleysheridan.co.uk
>
>
No. When I give a fixed seed to mt_srand(), each time I get the same
sequence of mt_rand()s. My question is wheather the actual algorithm
behind these functions is likely to change in the next version of PHP
or not.
Janek
--- End Message ---
--- Begin Message ---
Janek schreef:
> On Sun, Oct 5, 2008 at 10:05 PM, Ashley Sheridan
> <[EMAIL PROTECTED]> wrote:
>> On Sun, 2008-10-05 at 21:57 +0200, Janek wrote:
>>> I know, but I *want* to seed it. My goal is to have a fixed
>>> pseudorandom sequence for each integer (seed) and I don't want those
>>> sequences to change regarding PHP version.
>>>
>>> Janek
>>>
>>> On Sun, Oct 5, 2008 at 9:52 PM, Richard Heyes <[EMAIL PROTECTED]> wrote:
>>>>> I wonder whether I can rely on the stability of mt_srand() and
>>>>> mt_rand(). I want them to generate the same sequence for a fixed seed,
>>>>> regardless of PHP version. Do you think I can trust it?
>>>>> Janek
>>>> Keep in mind (if you're not already) that mt_rand() doesn't
>>>> technically need to be seeded.
>>>>
>>>> --
>>>> Richard Heyes
>>>>
>>>> HTML5 Graphing for FF, Chrome, Opera and Safari:
>>>> http://www.phpguru.org/RGraph
>>>>
>> Doesn't it also rely on the system clock as well?
>>
>>
>> Ash
>> www.ashleysheridan.co.uk
>>
>>
>
> No. When I give a fixed seed to mt_srand(), each time I get the same
> sequence of mt_rand()s. My question is wheather the actual algorithm
> behind these functions is likely to change in the next version of PHP
> or not.
not likely to change in the next version at all. but there is no guarantee that
somewhere down the road a new 'rand' algorythm won't be used either,
3 things to consider doing:
1. write your own php extension that copies the mt_srand() function as
it is now and use your extension's version of the function ... then you
can be sure it won't change.
2. ask the devs on [EMAIL PROTECTED] what they think the likelyhood
is that the output may change in the future.
3. pre-generate the sequences and store them, then use those pre-generated
sequences instead of using mt_srand() (obviously this may not be viable at all)
>
> Janek
>
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confronted gillion presently flakey expanded courses newsreader publicaccess
storages
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On Sun, Oct 5, 2008 at 1:00 PM, huaizong wang <[EMAIL PROTECTED]> wrote:
>
>
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--- Begin Message ---
Hi...ALL...
With Regads,
Hemant Patel
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--- Begin Message ---
My question is Whether I should go for Full Text Based search or Database
Search...?And is there algorithm in php which can help me in this case...?
--- End Message ---
--- Begin Message ---
The question is, what are you searching for in the records?
Thank you,
Micah Gersten
onShore Networks
Internal Developer
http://www.onshore.com
Hemant Patel wrote:
> My question is Whether I should go for Full Text Based search or Database
> Search...?And is there algorithm in php which can help me in this case...?
>
>
--- End Message ---
