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math formula

P: n/a
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
Jul 17 '05 #1
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5 Replies


P: n/a
On 2005-04-08, Wim Smit <wi*@vdhosting.nl> wrote:
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.


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
Jul 17 '05 #2

P: n/a
Wim Smit wrote:
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


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/
Jul 17 '05 #3

P: n/a
Thanks for the quick reply.

I tried to use this code now:

$x = (- log(1) - log(0.06/100))*100*673356;

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" <in*****@invalid.invalid> schreef in bericht
news:BE7C1758.2E294%in*****@invalid.invalid...
Wim Smit wrote:
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


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/

Jul 17 '05 #4

P: n/a
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" <ja***@aub.dk> schreef in bericht
news:sl*******************@tank.aub.dk...
On 2005-04-08, Wim Smit <wi*@vdhosting.nl> wrote:
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.


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

Jul 17 '05 #5

P: n/a
Wim Smit wrote:
Thanks for the quick reply.

I tried to use this code now:

$x = (- log(1) - log(0.06/100))*100*673356;

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

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


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/
Jul 17 '05 #6

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