PHP 4.0 Bug #6547: Maths calculation problem
| From: | pp dot foong at net-linx dot com dot my | Date: | Tue, 05 Sep 2000 10:14:57 +0000 |
| Subject: | PHP 4.0 Bug #6547: Maths calculation problem | ||
| Groups: | php.dev | ||
| Request: | Send a blank email to php-dev+get-32114@lists.php.net to get a copy of this message | ||
From: pp.foong@net-linx.com.my
Operating system: Linux 2.2.16
PHP version: 4.0.2
PHP Bug Type: Scripting Engine problem
Bug description: Maths calculation problem
The function below will show the sunrise or sunset time of the day $yday for a place based on its
latitude and longitude information.
It works well with php3.x and php4.x until 4.0.1pl2, but in php4.0.2, it will give the same result
for all sunrise and sunset and whatever latitude and longitude information passed to it. Some
calculating function might not function well in the version of php...
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function suntime ($latitude, $longitude, $timezone, $yday) {
$A = 1.5708;
$B = 3.14159;
$C = 4.71239;
$D = 6.28319;
$E = 0.0174533 * $latitude;
$F = 0.0174533 * $longitude;
$G = 0.261799 * $timezone;
$R = -.0145439;
for ($i = 0; $i < 2; $i++)
{
if (!$i) {$J = $A; $type = "rise";}
else {$J = $C; $type = "set"; }
$K = $yday + (($J - $F) / $D);
$L = ($K * .017202) - .0574039; // Solar Mean Anomoly
$M = $L + .0334405 * sin($L); // Solar True Longitude
$M += 4.93289 + (3.49066E-04) * sin(2 * $L);
// Quadrant Determination
if ($D == 0) {exit;}
while ($M < 0) {$M = ($M + $D);}
while ($M >= $D) {$M = ($M - $D);}
if (($M / $A) - intval($M / $A) == 0) {$M += 4.84814E-06;}
$P = sin($M) / cos($M); // Solar Right Ascension
$P = atan2(.91746 * $P, 1);
// Quadrant Adjustment
if ($M > $C) {$P += $D;}
else {if ($M > $A) {$P += $B;} }
$Q = .39782 * sin($M); // Solar Declination
$Q = $Q / sqrt(-$Q * $Q + 1);
$Q = atan2($Q, 1);
$S = $R - (sin($Q) * sin($E));
$S = $S / (cos($Q) * cos($E));
if (abs($S) > 1) {echo 'none';} // Null phenomenon
$S = $S / sqrt(-$S * $S + 1);
$S = $A - atan2($S, 1);
if ($type == 'rise') {$S = $D - $S ;}
$T = $S + $P - 0.0172028 * $K - 1.73364; // Local apparent time
$U = $T - $F; // Universal timer
$V = $U + $G; // Wall clock time
// Quadrant Determination
if ($D == 0) {exit;}
while ($V < 0) {$V = ($V + $D);}
while ($V >= $D) {$V = ($V - $D);}
$V = $V * 3.81972;
$hour = intval($V);
$min = intval((($V - $hour) * 60) + 0.5);
echo "<font size=\"1\" color=\"#ff0000\">sun$type: ";
echo date( "g:i A", mktime($hour,$min,0,$mon,$mday,$year) );
echo "</font><br>";
}
}
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