Subversion Repositories eFlore/Projets.eflore-projets

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Ignore whitespace Rev 1173 → Rev 1174

/tags/v5.12-baouque/scripts/modules/ifn/bibliotheque/proj4php/projCode/gauss.php
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 {
 
/**
*
*/
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 ));
}
 
/**
*
* @param type $p
* @return type
*/
public function forward( $p ) {
$lon = $p->x;
$lat = $p->y;
 
$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;
return $p;
}
 
/**
*
* @param type $p
* @return null
*/
public function inverse( $p ) {
$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 );
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 = $lat;
}
/* convergence failed */
if( !$i ) {
Proj4php::reportError( "gauss:inverse:convergence failed" );
return null;
}
$p->x = $lon;
$p->y = $lat;
return $p;
}
 
}
 
Proj4php::$proj['gauss'] = new Proj4phpProjGauss();