Using math functions in PHP 4.3.5

[Bill Stockwell]

I have upgraded PHP on our server (a RedHat 7.2 box) to version 4.3.5.
However,
now code I wrote in PHP before fails to work correctly. I have some
code that invokes the math function atan2 in connection with
converting rectangular to polar coordinates in a Web page. This used
to work in PHP 4.x (earlier version) but failed with 4.3.4 and now
with 4.3.5. I haven't found anything in the README files about this
-- any thoughts on how to make atan2 work?

[Andy Hassall]

On 8 Apr 2004 17:22:48 -0700, bs********@ucok.edu (Bill Stockwell) wrote:

I have upgraded PHP on our server (a RedHat 7.2 box) to version 4.3.5.
However,
now code I wrote in PHP before fails to work correctly. I have some
code that invokes the math function atan2 in connection with
converting rectangular to polar coordinates in a Web page. This used
to work in PHP 4.x (earlier version) but failed with 4.3.4 and now
with 4.3.5. I haven't found anything in the README files about this
-- any thoughts on how to make atan2 work?

Failed in what way?

atan2 works fine for me on PHP 4.3.5, and I've not specified anything special
with regards to maths modules.

Configure Command
'./configure' '--prefix=/usr' '--with-apxs2=/usr/apache2/bin/apxs'
'--with-config-file-path=/etc/apache2' '--enable-trans-sid' '--with-gd'
'--with-mysql=/usr/mysql' '--with-zlib-dir=/usr' '--with-jpeg'
'--with-jpeg-dir=/usr'

--
Andy Hassall <an**@andyh.co.uk> / Space: disk usage analysis tool
http://www.andyh.co.uk / http://www.andyhsoftware.co.uk/space

[Bill Stockwell]

Andy Hassall <an**@andyh.co.uk> wrote in message news:<71********************************@4ax.com>. ..

On 8 Apr 2004 17:22:48 -0700, bs********@ucok.edu (Bill Stockwell) wrote:

I have upgraded PHP on our server (a RedHat 7.2 box) to version 4.3.5.
However,
now code I wrote in PHP before fails to work correctly. I have some
code that invokes the math function atan2 in connection with
converting rectangular to polar coordinates in a Web page. This used
to work in PHP 4.x (earlier version) but failed with 4.3.4 and now
with 4.3.5. I haven't found anything in the README files about this
-- any thoughts on how to make atan2 work?

Failed in what way?

atan2 works fine for me on PHP 4.3.5, and I've not specified anything special
with regards to maths modules.

Configure Command
'./configure' '--prefix=/usr' '--with-apxs2=/usr/apache2/bin/apxs'
'--with-config-file-path=/etc/apache2' '--enable-trans-sid' '--with-gd'
'--with-mysql=/usr/mysql' '--with-zlib-dir=/usr' '--with-jpeg'
'--with-jpeg-dir=/usr'

It fails in that no matter what (x,y) point I give it, I get 0 back
for the angle. This did NOT happen with PHP 4.0.6 -- it worked just
fine then.

[Andy Hassall]

On 9 Apr 2004 06:57:15 -0700, bs********@ucok.edu (Bill Stockwell) wrote:

Andy Hassall <an**@andyh.co.uk> wrote in message news:<71********************************@4ax.com>. ..

On 8 Apr 2004 17:22:48 -0700, bs********@ucok.edu (Bill Stockwell) wrote:

>I have upgraded PHP on our server (a RedHat 7.2 box) to version 4.3.5.
> However,
>now code I wrote in PHP before fails to work correctly. I have some
>code that invokes the math function atan2 in connection with
>converting rectangular to polar coordinates in a Web page. This used
>to work in PHP 4.x (earlier version) but failed with 4.3.4 and now
>with 4.3.5. I haven't found anything in the README files about this
>-- any thoughts on how to make atan2 work?

Failed in what way?

atan2 works fine for me on PHP 4.3.5, and I've not specified anything special
with regards to maths modules.

Configure Command
'./configure' '--prefix=/usr' '--with-apxs2=/usr/apache2/bin/apxs'
'--with-config-file-path=/etc/apache2' '--enable-trans-sid' '--with-gd'
'--with-mysql=/usr/mysql' '--with-zlib-dir=/usr' '--with-jpeg'
'--with-jpeg-dir=/usr'

It fails in that no matter what (x,y) point I give it, I get 0 back
for the angle. This did NOT happen with PHP 4.0.6 -- it worked just
fine then.

Output of this script on PHP 4.3.5:

<pre>
<?php
$xrange = 3;
$yrange = 3;

print " ";
for ($x=-$xrange; $x<=$xrange; $x++)
printf(" %-6d", $x);

echo "\n";

for ($y=-$yrange; $y<=$yrange; $y++)
{
printf(" %-6d ", $y);

for ($x=-$xrange; $x<=$xrange; $x++)
{
printf(" %-3.3f", atan2($x, $y));
}
echo "\n";
}

?>
</pre>

Is:
-3 -2 -1 0 1 2 3
-3 -2.356 -2.554 -2.820 3.142 2.820 2.554 2.356
-2 -2.159 -2.356 -2.678 3.142 2.678 2.356 2.159
-1 -1.893 -2.034 -2.356 3.142 2.356 2.034 1.893
0 -1.571 -1.571 -1.571 0.000 1.571 1.571 1.571
1 -1.249 -1.107 -0.785 0.000 0.785 1.107 1.249
2 -0.983 -0.785 -0.464 0.000 0.464 0.785 0.983
3 -0.785 -0.588 -0.322 0.000 0.322 0.588 0.785

Which looks right to me.

So does this give all zeroes on your setup?

--
Andy Hassall <an**@andyh.co.uk> / Space: disk usage analysis tool
http://www.andyh.co.uk / http://www.andyhsoftware.co.uk/space