/** * Calculates the sidereal time for the given timestamp. * * @return float */ public function getSiderealTime() { $julianDay = new JulianDay($this->dateTime); $T = bcdiv(bcsub(strval($julianDay), '2451545.0'), '36525'); $T2 = bcpow($T, '2'); $T3 = bcpow($T, '3'); $term1 = '280.46061837'; $term2 = bcmul('360.98564736629', bcsub(strval($julianDay), '2451545.0')); $term3 = bcmul('0.000387933', $T2); $term4 = bcdiv($T3, '38710000'); $result = bcsub(bcadd(bcadd($term1, $term2), $term3), $term4); while (bccomp($result, 0) == -1) { $result = bcadd($result, '360'); } while (bccomp($result, '360') >= 1) { $result = bcsub($result, '360'); } $st = new Time(); $st->setHourAngle(floatval($result)); return $st->getValue(); }
public function testSetHourAngleWorksAsExpected() { $time = new Time(); $time->setHourAngle(100.596390417); $this->assertEquals(6.7064260278, $time->getValue()); }