/**
* @covers Marando\Meeus\Nutation\Nutation::meanObliquity
* @see p.148, ex. 22.a
*/
public function testMeanObliquity()
{
$ε0 = Nutation::meanObliquity(AstroDate::parse('1987-Apr-10'));
$this->assertEquals(Angle::dms(23, 26, 27.407), $ε0, 'ε0', 0.001);
}
public function test()
{
return;
$frame = Frame::ICRF();
$epoch = Epoch::J(2000);
echo $epoch->toDate()->toTDB();
echo "\n";
echo "\n";
exit;
$ra = \Marando\Units\Time::hms(11, 16, 46.6);
$dec = \Marando\Units\Angle::dms(5, 45, 32.5);
$dist = Distance::au(5.8);
echo "\n" . ($eq = new Equat($frame, $epoch, $ra, $dec, $dist));
echo "\n" . ($eq = (new Equat($frame, $epoch, $ra, $dec, $dist))->apparent());
echo "\n";
return;
$frame = Frame::ICRF();
$epoch = AstroDate::jd(2457335.472615741)->toEpoch();
$ra = \Marando\Units\Time::hms(11, 16, 46.6);
$dec = \Marando\Units\Angle::dms(5, 45, 32.5);
$dist = Distance::au(5.8);
echo "\n" . ($eq = new Equat($frame, $epoch, $ra, $dec, $dist));
echo "\n" . ($eq = (new Equat($frame, $epoch, $ra, $dec, $dist))->apparent());
$eq = new Equat($frame, $epoch, $ra, $dec, $dist);
$eq->topo = Geo::deg(27, -82);
echo "\n" . $eq->toHoriz();
echo "\n" . $eq->apparent();
echo "\n" . ($h = $eq->toHoriz());
echo "\n" . $h->az->deg . "\t" . $h->alt->deg;
echo "\n" . $eq->apparent(\Marando\Units\Pressure::mbar(100), \Marando\Units\Temperature::F(90), 0.85);
echo "\n" . $eq->toHoriz();
return;
$ra = \Marando\Units\Time::hours(14.424354);
$dec = \Marando\Units\Angle::deg(33.54366);
$dist = Distance::au(1.5);
$geo = Geo::deg(27, -82);
$e = new Equat(Frame::ICRF(), Epoch::jd(2455586), $ra, $dec, $dist);
$e->topo = $geo;
echo "\n\n" . $e;
echo "\n" . $e->apparent();
$e = new Equat(Frame::ICRF(), Epoch::jd(2455586), $ra, $dec, $dist);
$e->topo = $geo;
echo "\n" . $e->apparent();
$e = new Equat(Frame::ICRF(), Epoch::jd(2455586), $ra, $dec, $dist);
$e->topo = $geo;
echo "\n" . $e->toHoriz();
return;
$e = new Equat(Frame::ICRF(), Epoch::jd(2455586), $ra, $dec, $dist);
echo "\n\n" . $e;
echo "\n" . $e->apparent($geo);
echo "\n" . $e->apparent()->toHoriz($geo);
$e = new Equat(Frame::ICRF(), Epoch::jd(2455586), $ra, $dec, $dist);
echo "\n\n" . $e;
echo "\n" . $e->apparent();
echo "\n" . $e->apparent()->toHoriz();
$e = new Equat(Frame::ICRF(), Epoch::jd(2451586), $ra, $dec, $dist);
$e->topo = $geo;
echo "\n\n" . $e;
echo "\n" . $e->apparent();
echo "\n" . $e->apparent()->toHoriz();
return;
// Position of Mercury
$x = Distance::au(+1.18052679326447);
$y = Distance::au(-0.3650485652522116);
$z = Distance::au(-0.2123422968928603);
// Velocity of Mercury
$vx = Velocity::aud(0.02052320553396918);
$vy = Velocity::aud(0.02828864020900079);
$vz = Velocity::aud(0.01145246106968459);
// Frame & epoch
$frame = Frame::ICRF();
$epoch = AstroDate::parse('2015-Mar-20')->toEpoch();
$c = new Cartesian($frame, $epoch, $x, $y, $z, $vx, $vy, $vz);
echo "\n\n";
echo $c;
echo "\n\n";
echo $c->setUnit('km km/d');
echo "\n\n";
echo $c->setUnit('km km/s');
echo "\n\n";
echo $c->toEquat();
echo "\n\n";
echo $c->toEquat()->apparent();
echo "\n\n";
echo $c->toEquat()->apparent(Geo::deg(27, 278));
echo "\n\n";
echo $c->toEquat()->toHoriz(Geo::deg(27, 278));
echo "\n\n";
}
/**
* Finds the mean obliquity of the ecliptic (ε0) for a given date by using the
* coefficients provided by Laskar.
*
* By using this method the accuracy is estimated to be at 0".01 after 1000
* years and a few arc seconds after 10,000 years on either side of the
* epoch J2000. Also, this method is only valid over a period of 10,000 years
* on either side of J2000 and will throe an exception if attempted on out
* of range dates
*
* @param AstroDate $date Date to find ε0 for
* @return Angle Mean obliquity (ε0)
* @throws Exception Occurs with an out of range date, |year| > 10,000
*
* @see Meeus, Jean. Astronomical Algorithms. Richmond, Virg.: Willmann-Bell,
* 2009. 147. Print.
*/
public static function meanObliquityLaskar(AstroDate $date)
{
// Time factor
$t = ($date->copy()->toUTC()->jd - 2451545.0) / 36525;
// Check for out of range date
if (abs($t) >= 1) {
$msg = "The Laskar method is not valid for the year {$date->year}.";
throw new Exception($msg);
}
$ε0TermsLaskar = [Angle::dms(23, 26, 21.448)->rad, Angle::dms(0, 0, -4680.93)->rad, Angle::dms(0, 0, -1.55)->rad, Angle::dms(0, 0, 1999.25)->rad, Angle::dms(0, 0, -51.38)->rad, Angle::dms(0, 0, -249.67)->rad, Angle::dms(0, 0, -39.05)->rad, Angle::dms(0, 0, 7.12)->rad, Angle::dms(0, 0, 27.87)->rad, Angle::dms(0, 0, 5.79)->rad, Angle::dms(0, 0, 2.45)->rad];
$ε0 = static::Horner($t, $ε0TermsLaskar);
return Angle::rad($ε0);
}
public function testString()
{
$tests = ['0 0 1' => Angle::dms(0, 0, 1), '0 0 0.1' => Angle::dms(0, 0, 0, 1), '0 0 0.1' => Angle::dms(0, 0, 0, 0.1), '0 0 0.01' => Angle::dms(0, 0, 0, 0.01), '0 0 0.001' => Angle::dms(0, 0, 0, 0.001), '0 0 0.0001' => Angle::dms(0, 0, 0, 0.0001), '0 0 0.00001' => Angle::dms(0, 0, 0, 1.0E-5), '0 0 0.000001' => Angle::dms(0, 0, 0, 1.0E-6), '0 0 0.0000001' => Angle::dms(0, 0, 0, 1.0E-7), '0 0 0.00000001' => Angle::dms(0, 0, 0, 1.0E-8), '0 0 0.000000001' => Angle::dms(0, 0, 0, 1.0E-9), '-0 0 1' => Angle::dms(0, 0, -1), '-0 0 0.1' => Angle::dms(0, 0, 0, -1), '-0 0 0.1' => Angle::dms(0, 0, 0, -0.1), '-0 0 0.01' => Angle::dms(0, 0, 0, -0.01), '-0 0 0.001' => Angle::dms(0, 0, 0, -0.001), '-0 0 0.0001' => Angle::dms(0, 0, 0, -0.0001), '-0 0 0.00001' => Angle::dms(0, 0, 0, -1.0E-5), '-0 0 0.000001' => Angle::dms(0, 0, 0, -1.0E-6), '-0 0 0.0000001' => Angle::dms(0, 0, 0, -1.0E-7), '-0 0 0.00000001' => Angle::dms(0, 0, 0, -1.0E-8), '-0 0 0.000000001' => Angle::dms(0, 0, 0, -1.0E-9)];
foreach ($tests as $string => $angle) {
$this->assertEquals($string, $angle->format('d m s.9f'));
}
}
