New file |
0,0 → 1,74 |
<?php |
/** |
* Author : Julien Moquet |
* |
* Inspired by Proj4php from Mike Adair madairATdmsolutions.ca |
* and Richard Greenwood rich@greenwoodma$p->com |
* License: LGPL as per: http://www.gnu.org/copyleft/lesser.html |
*/ |
class Proj4phpProjGauss { |
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/** |
* |
*/ |
public function init() { |
|
$sphi = sin( $this->lat0 ); |
$cphi = cos( $this->lat0 ); |
$cphi *= $cphi; |
$this->rc = sqrt( 1.0 - $this->es ) / (1.0 - $this->es * $sphi * $sphi); |
$this->C = sqrt( 1.0 + $this->es * $cphi * $cphi / (1.0 - $this->es) ); |
$this->phic0 = asin( $sphi / $this->C ); |
$this->ratexp = 0.5 * $this->C * $this->e; |
$this->K = tan( 0.5 * $this->phic0 + Proj4php::$common->FORTPI ) / (pow( tan( 0.5 * $this->lat0 + Proj4php::$common->FORTPI ), $this->C ) * Proj4php::$common->srat( $this->e * $sphi, $this->ratexp )); |
} |
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/** |
* |
* @param type $p |
* @return type |
*/ |
public function forward( $p ) { |
$lon = $p->x; |
$lat = $p->y; |
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$p->y = 2.0 * atan( $this->K * pow( tan( 0.5 * $lat + Proj4php::$common->FORTPI ), $this->C ) * Proj4php::$common->srat( $this->e * sin( $lat ), $this->ratexp ) ) - Proj4php::$common->HALF_PI; |
$p->x = $this->C * $lon; |
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return $p; |
} |
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/** |
* |
* @param type $p |
* @return null |
*/ |
public function inverse( $p ) { |
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$DEL_TOL = 1e-14; |
$lon = $p->x / $this->C; |
$lat = $p->y; |
$num = pow( tan( 0.5 * $lat + Proj4php::$common . FORTPI ) / $this->K, 1. / $this->C ); |
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for( $i = Proj4php::$common . MAX_ITER; $i > 0; --$i ) { |
$lat = 2.0 * atan( $num * Proj4php::$common->srat( $this->e * sin( $p->y ), -0.5 * $this->e ) ) - Proj4php::$common->HALF_PI; |
if( abs( $lat - $p->y ) < $DEL_TOL ) |
break; |
$p->y = $lat; |
} |
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/* convergence failed */ |
if( !$i ) { |
Proj4php::reportError( "gauss:inverse:convergence failed" ); |
return null; |
} |
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$p->x = $lon; |
$p->y = $lat; |
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return $p; |
} |
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} |
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Proj4php::$proj['gauss'] = new Proj4phpProjGauss(); |