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<?php/*** Author : Julien Moquet** Inspired by Proj4js from Mike Adair madairATdmsolutions.ca* and Richard Greenwood rich@greenwoodmap.com* License: LGPL as per: http://www.gnu.org/copyleft/lesser.html*/class Proj4phpCommon {public $PI = M_PI; #3.141592653589793238; //Math.PI,public $HALF_PI = M_PI_2; #1.570796326794896619; //Math.PI*0.5,public $TWO_PI = 6.283185307179586477; //Math.PI*2,public $FORTPI = 0.78539816339744833;public $R2D = 57.29577951308232088;public $D2R = 0.01745329251994329577;public $SEC_TO_RAD = 4.84813681109535993589914102357e-6; /* SEC_TO_RAD = Pi/180/3600 */public $EPSLN = 1.0e-10;public $MAX_ITER = 20;// following constants from geocent.cpublic $COS_67P5 = 0.38268343236508977; /* cosine of 67.5 degrees */public $AD_C = 1.0026000; /* Toms region 1 constant *//* datum_type values */public $PJD_UNKNOWN = 0;public $PJD_3PARAM = 1;public $PJD_7PARAM = 2;public $PJD_GRIDSHIFT = 3;public $PJD_WGS84 = 4; // WGS84 or equivalentpublic $PJD_NODATUM = 5; // WGS84 or equivalentconst SRS_WGS84_SEMIMAJOR = 6378137.0; // only used in grid shift transforms// ellipoid pj_set_ell.cpublic $SIXTH = .1666666666666666667; /* 1/6 */public $RA4 = .04722222222222222222; /* 17/360 */public $RA6 = .02215608465608465608; /* 67/3024 */public $RV4 = .06944444444444444444; /* 5/72 */public $RV6 = .04243827160493827160; /* 55/1296 *//* meridinal distance for ellipsoid and inverse* * 8th degree - accurate to < 1e-5 meters when used in conjuction* * with typical major axis values.* * Inverse determines phi to EPS (1e-11) radians, about 1e-6 seconds.*/protected $C00 = 1.0;protected $C02 = .25;protected $C04 = .046875;protected $C06 = .01953125;protected $C08 = .01068115234375;protected $C22 = .75;protected $C44 = .46875;protected $C46 = .01302083333333333333;protected $C48 = .00712076822916666666;protected $C66 = .36458333333333333333;protected $C68 = .00569661458333333333;protected $C88 = .3076171875;/*** Function to compute the constant small m which is the radius of* a parallel of latitude, phi, divided by the semimajor axis.** @param type $eccent* @param type $sinphi* @param type $cosphi* @return type*/public function msfnz( $eccent, $sinphi, $cosphi ) {$con = $eccent * $sinphi;return $cosphi / (sqrt( 1.0 - $con * $con ));}/*** Function to compute the constant small t for use in the forward* computations in the Lambert Conformal Conic and the Polar* Stereographic projections.** @param type $eccent* @param type $phi* @param type $sinphi* @return type*/public function tsfnz( $eccent, $phi, $sinphi ) {$con = $eccent * $sinphi;$com = 0.5 * $eccent;$con = pow( ((1.0 - $con) / (1.0 + $con) ), $com );return (tan( .5 * (M_PI_2 - $phi) ) / $con);}/*** Function to compute the latitude angle, phi2, for the inverse of the* Lambert Conformal Conic and Polar Stereographic projections.** rise up an assertion if there is no convergence.** @param type $eccent* @param type $ts* @return type*/public function phi2z( $eccent, $ts ) {$eccnth = .5 * $eccent;$phi = M_PI_2 - 2 * atan( $ts );for( $i = 0; $i <= 15; $i++ ) {$con = $eccent * sin( $phi );$dphi = M_PI_2 - 2 * atan( $ts * (pow( ((1.0 - $con) / (1.0 + $con) ), $eccnth )) ) - $phi;$phi += $dphi;if( abs( $dphi ) <= .0000000001 )return $phi;}assert( "false; /* phi2z has NoConvergence */" );return (-9999);}/*** Function to compute constant small q which is the radius of a* parallel of latitude, phi, divided by the semimajor axis.** @param type $eccent* @param type $sinphi* @return type*/public function qsfnz( $eccent, $sinphi ) {if( $eccent > 1.0e-7 ) {$con = $eccent * $sinphi;return (( 1.0 - $eccent * $eccent) * ($sinphi / (1.0 - $con * $con) - (.5 / $eccent) * log( (1.0 - $con) / (1.0 + $con) )));}return (2.0 * $sinphi);}/*** Function to eliminate roundoff errors in asin** @param type $x* @return type*/public function asinz( $x ) {return asin(abs( $x ) > 1.0 ? ($x > 1.0 ? 1.0 : -1.0) : $x);#if( abs( $x ) > 1.0 ) {# $x = ($x > 1.0) ? 1.0 : -1.0;#}#return asin( $x );}/*** following functions from gctpc cproj.c for transverse mercator projections** @param type $x* @return type*/public function e0fn( $x ) {return (1.0 - 0.25 * $x * (1.0 + $x / 16.0 * (3.0 + 1.25 * $x)));}/**** @param type $x* @return type*/public function e1fn( $x ) {return (0.375 * $x * (1.0 + 0.25 * $x * (1.0 + 0.46875 * $x)));}/**** @param type $x* @return type*/public function e2fn( $x ) {return (0.05859375 * $x * $x * (1.0 + 0.75 * $x));}/**** @param type $x* @return type*/public function e3fn( $x ) {return ($x * $x * $x * (35.0 / 3072.0));}/**** @param type $e0* @param type $e1* @param type $e2* @param type $e3* @param type $phi* @return type*/public function mlfn( $e0, $e1, $e2, $e3, $phi ) {return ($e0 * $phi - $e1 * sin( 2.0 * $phi ) + $e2 * sin( 4.0 * $phi ) - $e3 * sin( 6.0 * $phi ));}/**** @param type $esinp* @param type $exp* @return type*/public function srat( $esinp, $exp ) {return (pow( (1.0 - $esinp) / (1.0 + $esinp), $exp ));}/*** Function to return the sign of an argument** @param type $x* @return type*/public function sign( $x ) {return $x < 0.0 ? -1 : 1;}/*** Function to adjust longitude to -180 to 180; input in radians** @param type $x* @return type*/public function adjust_lon( $x ) {return (abs( $x ) < M_PI) ? $x : ($x - ($this->sign( $x ) * $this->TWO_PI) );}/*** IGNF - DGR : algorithms used by IGN France* Function to adjust latitude to -90 to 90; input in radians** @param type $x* @return type*/public function adjust_lat( $x ) {$x = (abs( $x ) < M_PI_2) ? $x : ($x - ($this->sign( $x ) * M_PI) );return $x;}/*** Latitude Isometrique - close to tsfnz ...** @param type $eccent* @param float $phi* @param type $sinphi* @return string*/public function latiso( $eccent, $phi, $sinphi ) {if( abs( $phi ) > M_PI_2 )return +NaN;if( $phi == M_PI_2 )return INF;if( $phi == -1.0 * M_PI_2 )return -1.0 * INF;$con = $eccent * $sinphi;return log( tan( (M_PI_2 + $phi) / 2.0 ) ) + $eccent * log( (1.0 - $con) / (1.0 + $con) ) / 2.0;}/**** @param type $x* @param type $L* @return type*/public function fL( $x, $L ) {return 2.0 * atan( $x * exp( $L ) ) - M_PI_2;}/*** Inverse Latitude Isometrique - close to ph2z** @param type $eccent* @param type $ts* @return type*/public function invlatiso( $eccent, $ts ) {$phi = $this->fL( 1.0, $ts );$Iphi = 0.0;$con = 0.0;do {$Iphi = $phi;$con = $eccent * sin( $Iphi );$phi = $this->fL( exp( $eccent * log( (1.0 + $con) / (1.0 - $con) ) / 2.0 ), $ts );} while( abs( $phi - $Iphi ) > 1.0e-12 );return $phi;}/*** Grande Normale** @param type $a* @param type $e* @param type $sinphi* @return type*/public function gN( $a, $e, $sinphi ) {$temp = $e * $sinphi;return $a / sqrt( 1.0 - $temp * $temp );}/*** code from the PROJ.4 pj_mlfn.c file; this may be useful for other projections** @param type $es* @return type*/public function pj_enfn( $es ) {$en = array( );$en[0] = $this->C00 - $es * ($this->C02 + $es * ($this->C04 + $es * ($this->C06 + $es * $this->C08)));$en[1] = es * ($this->C22 - $es * ($this->C04 + $es * ($this->C06 + $es * $this->C08)));$t = $es * $es;$en[2] = $t * ($this->C44 - $es * ($this->C46 + $es * $this->C48));$t *= $es;$en[3] = $t * ($this->C66 - $es * $this->C68);$en[4] = $t * $es * $this->C88;return $en;}/**** @param type $phi* @param type $sphi* @param type $cphi* @param type $en* @return type*/public function pj_mlfn( $phi, $sphi, $cphi, $en ) {$cphi *= $sphi;$sphi *= $sphi;return ($en[0] * $phi - $cphi * ($en[1] + $sphi * ($en[2] + $sphi * ($en[3] + $sphi * $en[4]))));}/**** @param type $arg* @param type $es* @param type $en* @return type*/public function pj_inv_mlfn( $arg, $es, $en ) {$k = (float) 1 / (1 - $es);$phi = $arg;for( $i = Proj4php::$common->MAX_ITER; $i; --$i ) { /* rarely goes over 2 iterations */$s = sin( $phi );$t = 1. - $es * $s * $s;//$t = $this->pj_mlfn($phi, $s, cos($phi), $en) - $arg;//$phi -= $t * ($t * sqrt($t)) * $k;$t = ($this->pj_mlfn( $phi, $s, cos( $phi ), $en ) - $arg) * ($t * sqrt( $t )) * $k;$phi -= $t;if( abs( $t ) < Proj4php::$common->EPSLN )return $phi;}Proj4php::reportError( "cass:pj_inv_mlfn: Convergence error" );return $phi;}}