src/Common.php
public static 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 + $con)) / 2.0;
    }
public static function latiso($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;
    }
public static 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 ; }
Latitude Isometrique - close to tsfnz ...

@param float $eccent
@param float $phi
@param float $sinphi
@return float
Latitude Isometrique - close to tsfnz ...