math formula

[Wim Smit]

I am trying to put the following math formula in php, but I know to little
of math to do it I guess, maybe somebody can help me out.

This is the formula:

x = (-ln(1) - ln(y/100))*100*z

The values for y and z will be submitted via a form.
Any help is greatly apreciated.

Wim

[Jacob Atzen]

Re: math formula

On 2005-04-08, Wim Smit <wim@vdhosting. nl> wrote:[color=blue]
> I am trying to put the following math formula in php, but I know to little
> of math to do it I guess, maybe somebody can help me out.
>
> This is the formula:
>
> x = (-ln(1) - ln(y/100))*100*z
>
> The values for y and z will be submitted via a form.
> Any help is greatly apreciated.[/color]

Start by learning how to submit a variable through a form. Then move on
to processing the variable. The PHP manual will tell you how to do this.

--
Cheers
- Jacob Atzen

[Philip Ronan]

Re: math formula

Wim Smit wrote:
[color=blue]
> I am trying to put the following math formula in php, but I know to little
> of math to do it I guess, maybe somebody can help me out.
>
> This is the formula:
>
> x = (-ln(1) - ln(y/100))*100*z
>
> The values for y and z will be submitted via a form.
> Any help is greatly apreciated.
>
> Wim
>
>[/color]

The PHP function for natural logarithms is log(), not ln(). Variable names
start with a $ symbol, e.g.:

$x = $_GET['x'];
$y = $_GET['y'];

Fix that, put a semicolon at the end and it should work.

BTW, ln(1) is equal to zero, so you can delete it from your equation.

--
phil [dot] ronan @ virgin [dot] net

http://vzone.virgin.net/phil.ronan/

[Wim Smit]

Re: math formula

Thanks for the quick reply.

I tried to use this code now:

$x = (- log(1) - log(0.06/100))*100*67335 6;

The value of $x is 499534596.235
However the value of $x should be 4645225.

U sure log() in PHP does the same as ln()?

Wim


"Philip Ronan" <invalid@invali d.invalid> schreef in bericht
news:BE7C1758.2 E294%invalid@in valid.invalid.. .[color=blue]
> Wim Smit wrote:
>[color=green]
>> I am trying to put the following math formula in php, but I know to
>> little
>> of math to do it I guess, maybe somebody can help me out.
>>
>> This is the formula:
>>
>> x = (-ln(1) - ln(y/100))*100*z
>>
>> The values for y and z will be submitted via a form.
>> Any help is greatly apreciated.
>>
>> Wim
>>
>>[/color]
>
> The PHP function for natural logarithms is log(), not ln(). Variable names
> start with a $ symbol, e.g.:
>
> $x = $_GET['x'];
> $y = $_GET['y'];
>
> Fix that, put a semicolon at the end and it should work.
>
> BTW, ln(1) is equal to zero, so you can delete it from your equation.
>
> --
> phil [dot] ronan @ virgin [dot] net
> http://vzone.virgin.net/phil.ronan/
>
>[/color]

[Wim Smit]

Re: math formula

Submitting a variable won't be the problem, it is getting PHP to do the
formula correctly.
ln() does not show up in the manual, likely there is a way around that, but
I know to little of math on how to solve that. :).

Wim


"Jacob Atzen" <jacob@aub.dk > schreef in bericht
news:slrnd5cm37 .2psh.jacob@tan k.aub.dk...[color=blue]
> On 2005-04-08, Wim Smit <wim@vdhosting. nl> wrote:[color=green]
>> I am trying to put the following math formula in php, but I know to
>> little
>> of math to do it I guess, maybe somebody can help me out.
>>
>> This is the formula:
>>
>> x = (-ln(1) - ln(y/100))*100*z
>>
>> The values for y and z will be submitted via a form.
>> Any help is greatly apreciated.[/color]
>
> Start by learning how to submit a variable through a form. Then move on
> to processing the variable. The PHP manual will tell you how to do this.
>
> --
> Cheers
> - Jacob Atzen[/color]

[Philip Ronan]

Re: math formula

Wim Smit wrote:
[color=blue]
> Thanks for the quick reply.
>
> I tried to use this code now:
>
> $x = (- log(1) - log(0.06/100))*100*67335 6;
>
> The value of $x is 499534596.235[/color]

That is correct
[color=blue]
> However the value of $x should be 4645225.[/color]

That is incorrect
[color=blue]
>
> U sure log() in PHP does the same as ln()?[/color]

log() is a natural logarithm function. That's what you want, isn't it?

Use log10() if you want base 10 logarithms

Take a look at <http://uk.php.net/log> and <http://uk.php.net/log10>

--
phil [dot] ronan @ virgin [dot] net

http://vzone.virgin.net/phil.ronan/