Commit df349606 authored by Michael Adair's avatar Michael Adair
Browse files

closes #66: change implementation to match PROJ.4 code for spherical and... 

closes #66: change implementation to match PROJ.4 code for spherical and non-spherical forms for sinu projection
parent a4641a0d

lib/proj4js-combined.js

+118 −78
Original line number Diff line number Diff line
@@ -1215,7 +1215,61 @@ Proj4js.common = { 
  {

    var temp= e*sinphi;

    return a/Math.sqrt(1.0 - temp*temp);

  },

  

  //code from the PROJ.4 pj_mlfn.c file;  this may be useful for other projections

  pj_enfn: function(es) {

    var en = new 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)));

    var 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;

  },

  

  pj_mlfn: function(phi, sphi, cphi, en) {

    cphi *= sphi;

    sphi *= sphi;

    return(en[0] * phi - cphi * (en[1] + sphi*(en[2]+ sphi*(en[3] + sphi*en[4]))));

  },

  

  pj_inv_mlfn: function(arg, es, en) {

    var k = 1./(1.-es);

    var phi = arg;

    for (var i = Proj4js.common.MAX_ITER; i ; --i) { /* rarely goes over 2 iterations */

      var s = Math.sin(phi);

      t = 1. - es * s * s;

      //t = this.pj_mlfn(phi, s, Math.cos(phi), en) - arg;

      //phi -= t * (t * Math.sqrt(t)) * k;

      t = (this.pj_mlfn(phi, s, Math.cos(phi), en) - arg) * (t * Math.sqrt(t)) * k;

      phi -= t;

      if (Math.abs(t) < Proj4js.common.EPSLN)

        return phi;

    }

    Proj4js.reportError("cass:pj_inv_mlfn: Convergence error");

    return phi;

  },



/* 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.

*/

  C00: 1.0,

  C02: .25,

  C04: .046875,

  C06: .01953125,

  C08: .01068115234375,

  C22: .75,

  C44: .46875,

  C46: .01302083333333333333,

  C48: .00712076822916666666,

  C66: .36458333333333333333,

  C68: .00569661458333333333,

  C88: .3076171875  



};
@@ -3879,7 +3933,18 @@ Proj4js.Proj.sinu = { 
	init: function() {

		/* Place parameters in static storage for common use

		  -------------------------------------------------*/

		this.R = 6370997.0; //Radius of earth

		  



		if (!this.sphere) {

		  this.en = Proj4js.common.pj_enfn(this.es);

    } else {

      this.n = 1.;

      this.m = 0.;

      this.es = 0;

      this.C_y = Math.sqrt((this.m + 1.) / this.n);

      this.C_x = this.C_y/(this.m + 1.);

    }

		  

	},



	/* Sinusoidal forward equations--mapping lat,long to x,y
@@ -3890,9 +3955,28 @@ Proj4js.Proj.sinu = { 
		var lat=p.y;	

		/* Forward equations

		-----------------*/

		delta_lon = Proj4js.common.adjust_lon(lon - this.long0);

		x = this.R * delta_lon * Math.cos(lat) + this.x0;

		y = this.R * lat + this.y0;

		lon = Proj4js.common.adjust_lon(lon - this.long0);

		

		if (this.sphere) {

      if (!this.m) {

        lat = this.n != 1. ? Math.asin(this.n * Math.sin(lat)): lat;

      } else {

        k = this.n * Math.sin(lat);

        for (var i = Proj4js.common.MAX_ITER; i ; --i) {

          lat -= V = (this.m * lat + Math.sin(lat) - k) / (this.m + Math.cos(lat));

          if (Math.abs(V) < Proj4js.common.EPSLN) break;

        }

      }

      x = this.a * this.C_x * lon * (this.m + Math.cos(lat));

      y = this.a * this.C_y * lat;



		} else {

		  

		  var s = Math.sin(lat);

		  var c = Math.cos(lat);

      y = this.a * Proj4js.common.pj_mlfn(lat, s, c, this.en);

      x = this.a * lon * c / Math.sqrt(1. - this.es * s * s);

		}



		p.x=x;

		p.y=y;
@@ -3906,16 +3990,27 @@ Proj4js.Proj.sinu = { 
		  -----------------*/

		p.x -= this.x0;

		p.y -= this.y0;

		lat = p.y / this.R;

		if (Math.abs(lat) > Proj4js.common.HALF_PI) {

		    Proj4js.reportError("sinu:Inv:DataError");

		}

		temp = Math.abs(lat) - Proj4js.common.HALF_PI;

		if (Math.abs(temp) > Proj4js.common.EPSLN) {

			temp = this.long0+ p.x / (this.R *Math.cos(lat));

			lon = Proj4js.common.adjust_lon(temp);

		lat = p.y / this.a;

		

		if (this.sphere) {

		  

      p.y /= this.C_y;

      lat = this.m ? Math.asin((this.m * p.y + Math.sin(p.y)) / this.n) :

        ( this.n != 1. ? Math.asin(sin(p.y) / this.n) : p.y );

      lon = p.x / (this.C_x * (this.m + Math.cos(p.y)));

		  

		} else {

		  lat = Proj4js.common.pj_inv_mlfn(p.y/this.a, this.es, this.en)

		  var s = Math.abs(lat);

      if (s < Proj4js.common.HALF_PI) {

        s = Math.sin(lat);

        temp = this.long0 + p.x * Math.sqrt(1. - this.es * s * s) /(this.a * Math.cos(lat));

        //temp = this.long0 + p.x / (this.a * Math.cos(lat));

        lon = Proj4js.common.adjust_lon(temp);

      } else if ((s - Proj4js.common.EPSLN) < Proj4js.common.HALF_PI) {

        lon = this.long0;

      }

		  

		}

		  

		p.x=lon;
@@ -4234,8 +4329,8 @@ ALGORITHM REFERENCES 
Proj4js.Proj.cass = {

  init : function() {

    if (!this.sphere) {

      this.en = this.pj_enfn(this.es)

      this.m0 = this.pj_mlfn(this.lat0, Math.sin(this.lat0), Math.cos(this.lat0), this.en);

      this.en = Proj4js.common.pj_enfn(this.es)

      this.m0 = Proj4js.common.pj_mlfn(this.lat0, Math.sin(this.lat0), Math.cos(this.lat0), this.en);

    }

  },
@@ -4264,7 +4359,7 @@ Proj4js.Proj.cass = { 
        //ellipsoid

      this.n = Math.sin(phi);

      this.c = Math.cos(phi);

      y = this.pj_mlfn(phi, this.n, this.c, this.en);

      y = Proj4js.common.pj_mlfn(phi, this.n, this.c, this.en);

      this.n = 1./Math.sqrt(1. - this.es * this.n * this.n);

      this.tn = Math.tan(phi); 

      this.t = this.tn * this.tn;
@@ -4295,7 +4390,7 @@ Proj4js.Proj.cass = { 
      lam = Math.atan2(Math.tan(x), Math.cos(this.dd));

    } else {

      /* ellipsoid */

      var ph1 = this.pj_inv_mlfn(this.m0 + y, this.es, this.en);

      var ph1 = Proj4js.common.pj_inv_mlfn(this.m0 + y, this.es, this.en);

      this.tn = Math.tan(ph1); 

      this.t = this.tn * this.tn;

      this.n = Math.sin(ph1);
@@ -4310,62 +4405,7 @@ Proj4js.Proj.cass = { 
    p.x = Proj4js.common.adjust_lon(this.long0+lam);

    p.y = phi;

    return p;

  },//lamazInv()





  //code from the PROJ.4 pj_mlfn.c file;  this may be useful for other projections

  pj_enfn: function(es) {

    var en = new 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)));

    var 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;

  },

  

  pj_mlfn: function(phi, sphi, cphi, en) {

    cphi *= sphi;

    sphi *= sphi;

    return(en[0] * phi - cphi * (en[1] + sphi*(en[2]+ sphi*(en[3] + sphi*en[4]))));

  },

  

  pj_inv_mlfn: function(arg, es, en) {

    var k = 1./(1.-es);

    var phi = arg;

    for (var i = Proj4js.common.MAX_ITER; i ; --i) { /* rarely goes over 2 iterations */

      var s = Math.sin(phi);

      t = 1. - es * s * s;

      //t = this.pj_mlfn(phi, s, Math.cos(phi), en) - arg;

      //phi -= t * (t * Math.sqrt(t)) * k;

      t = (this.pj_mlfn(phi, s, Math.cos(phi), en) - arg) * (t * Math.sqrt(t)) * k;

      phi -= t;

      if (Math.abs(t) < Proj4js.common.EPSLN)

        return phi;

    }

    Proj4js.reportError("cass:pj_inv_mlfn: Convergence error");

    return phi;

  },



/* 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.

*/

  C00: 1.0,

  C02: .25,

  C04: .046875,

  C06: .01953125,

  C08: .01068115234375,

  C22: .75,

  C44: .46875,

  C46: .01302083333333333333,

  C48: .00712076822916666666,

  C66: .36458333333333333333,

  C68: .00569661458333333333,

  C88: .3076171875

  }//cassInv()



}

/* ======================================================================
@@ -5062,9 +5102,9 @@ Proj4js.Proj.laea = { 
          y = cosz * rh;

          break;

        case this.OBLIQ:

          phi = (Math.abs(rh) <= Proj4js.common.EPSLN) ? this.phi0 : Math.asin(cosz * sinph0 + y * sinz * cosph0 / rh);

          x *= sinz * cosph0;

          y = (cosz - Math.sin(phi) * sinph0) * rh;

          phi = (Math.abs(rh) <= Proj4js.common.EPSLN) ? this.phi0 : Math.asin(cosz * this.sinph0 + y * sinz * this.cosph0 / rh);

          x *= sinz * this.cosph0;

          y = (cosz - Math.sin(phi) * this.sinph0) * rh;

          break;

        case this.N_POLE:

          y = -y;

lib/proj4js-compressed.js

+12 −10

File changed.

Preview size limit exceeded, changes collapsed.

lib/proj4js.js

+55 −1
Original line number Diff line number Diff line
@@ -1200,7 +1200,61 @@ Proj4js.common = { 
  {

    var temp= e*sinphi;

    return a/Math.sqrt(1.0 - temp*temp);

  },

  

  //code from the PROJ.4 pj_mlfn.c file;  this may be useful for other projections

  pj_enfn: function(es) {

    var en = new 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)));

    var 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;

  },

  

  pj_mlfn: function(phi, sphi, cphi, en) {

    cphi *= sphi;

    sphi *= sphi;

    return(en[0] * phi - cphi * (en[1] + sphi*(en[2]+ sphi*(en[3] + sphi*en[4]))));

  },

  

  pj_inv_mlfn: function(arg, es, en) {

    var k = 1./(1.-es);

    var phi = arg;

    for (var i = Proj4js.common.MAX_ITER; i ; --i) { /* rarely goes over 2 iterations */

      var s = Math.sin(phi);

      t = 1. - es * s * s;

      //t = this.pj_mlfn(phi, s, Math.cos(phi), en) - arg;

      //phi -= t * (t * Math.sqrt(t)) * k;

      t = (this.pj_mlfn(phi, s, Math.cos(phi), en) - arg) * (t * Math.sqrt(t)) * k;

      phi -= t;

      if (Math.abs(t) < Proj4js.common.EPSLN)

        return phi;

    }

    Proj4js.reportError("cass:pj_inv_mlfn: Convergence error");

    return phi;

  },



/* 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.

*/

  C00: 1.0,

  C02: .25,

  C04: .046875,

  C06: .01953125,

  C08: .01068115234375,

  C22: .75,

  C44: .46875,

  C46: .01302083333333333333,

  C48: .00712076822916666666,

  C66: .36458333333333333333,

  C68: .00569661458333333333,

  C88: .3076171875  



};

lib/projCode/cass.js

+5 −60
Original line number Diff line number Diff line
@@ -27,8 +27,8 @@ ALGORITHM REFERENCES 
Proj4js.Proj.cass = {

  init : function() {

    if (!this.sphere) {

      this.en = this.pj_enfn(this.es)

      this.m0 = this.pj_mlfn(this.lat0, Math.sin(this.lat0), Math.cos(this.lat0), this.en);

      this.en = Proj4js.common.pj_enfn(this.es)

      this.m0 = Proj4js.common.pj_mlfn(this.lat0, Math.sin(this.lat0), Math.cos(this.lat0), this.en);

    }

  },
@@ -57,7 +57,7 @@ Proj4js.Proj.cass = { 
        //ellipsoid

      this.n = Math.sin(phi);

      this.c = Math.cos(phi);

      y = this.pj_mlfn(phi, this.n, this.c, this.en);

      y = Proj4js.common.pj_mlfn(phi, this.n, this.c, this.en);

      this.n = 1./Math.sqrt(1. - this.es * this.n * this.n);

      this.tn = Math.tan(phi); 

      this.t = this.tn * this.tn;
@@ -88,7 +88,7 @@ Proj4js.Proj.cass = { 
      lam = Math.atan2(Math.tan(x), Math.cos(this.dd));

    } else {

      /* ellipsoid */

      var ph1 = this.pj_inv_mlfn(this.m0 + y, this.es, this.en);

      var ph1 = Proj4js.common.pj_inv_mlfn(this.m0 + y, this.es, this.en);

      this.tn = Math.tan(ph1); 

      this.t = this.tn * this.tn;

      this.n = Math.sin(ph1);
@@ -103,61 +103,6 @@ Proj4js.Proj.cass = { 
    p.x = Proj4js.common.adjust_lon(this.long0+lam);

    p.y = phi;

    return p;

  },//lamazInv()





  //code from the PROJ.4 pj_mlfn.c file;  this may be useful for other projections

  pj_enfn: function(es) {

    var en = new 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)));

    var 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;

  },

  

  pj_mlfn: function(phi, sphi, cphi, en) {

    cphi *= sphi;

    sphi *= sphi;

    return(en[0] * phi - cphi * (en[1] + sphi*(en[2]+ sphi*(en[3] + sphi*en[4]))));

  },

  

  pj_inv_mlfn: function(arg, es, en) {

    var k = 1./(1.-es);

    var phi = arg;

    for (var i = Proj4js.common.MAX_ITER; i ; --i) { /* rarely goes over 2 iterations */

      var s = Math.sin(phi);

      t = 1. - es * s * s;

      //t = this.pj_mlfn(phi, s, Math.cos(phi), en) - arg;

      //phi -= t * (t * Math.sqrt(t)) * k;

      t = (this.pj_mlfn(phi, s, Math.cos(phi), en) - arg) * (t * Math.sqrt(t)) * k;

      phi -= t;

      if (Math.abs(t) < Proj4js.common.EPSLN)

        return phi;

    }

    Proj4js.reportError("cass:pj_inv_mlfn: Convergence error");

    return phi;

  },



/* 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.

*/

  C00: 1.0,

  C02: .25,

  C04: .046875,

  C06: .01953125,

  C08: .01068115234375,

  C22: .75,

  C44: .46875,

  C46: .01302083333333333333,

  C48: .00712076822916666666,

  C66: .36458333333333333333,

  C68: .00569661458333333333,

  C88: .3076171875

  }//cassInv()



}

lib/projCode/sinu.js

+55 −14
Original line number Diff line number Diff line
@@ -31,7 +31,18 @@ Proj4js.Proj.sinu = { 
	init: function() {

		/* Place parameters in static storage for common use

		  -------------------------------------------------*/

		this.R = 6370997.0; //Radius of earth

		  



		if (!this.sphere) {

		  this.en = Proj4js.common.pj_enfn(this.es);

    } else {

      this.n = 1.;

      this.m = 0.;

      this.es = 0;

      this.C_y = Math.sqrt((this.m + 1.) / this.n);

      this.C_x = this.C_y/(this.m + 1.);

    }

		  

	},



	/* Sinusoidal forward equations--mapping lat,long to x,y
@@ -42,9 +53,28 @@ Proj4js.Proj.sinu = { 
		var lat=p.y;	

		/* Forward equations

		-----------------*/

		delta_lon = Proj4js.common.adjust_lon(lon - this.long0);

		x = this.R * delta_lon * Math.cos(lat) + this.x0;

		y = this.R * lat + this.y0;

		lon = Proj4js.common.adjust_lon(lon - this.long0);

		

		if (this.sphere) {

      if (!this.m) {

        lat = this.n != 1. ? Math.asin(this.n * Math.sin(lat)): lat;

      } else {

        k = this.n * Math.sin(lat);

        for (var i = Proj4js.common.MAX_ITER; i ; --i) {

          lat -= V = (this.m * lat + Math.sin(lat) - k) / (this.m + Math.cos(lat));

          if (Math.abs(V) < Proj4js.common.EPSLN) break;

        }

      }

      x = this.a * this.C_x * lon * (this.m + Math.cos(lat));

      y = this.a * this.C_y * lat;



		} else {

		  

		  var s = Math.sin(lat);

		  var c = Math.cos(lat);

      y = this.a * Proj4js.common.pj_mlfn(lat, s, c, this.en);

      x = this.a * lon * c / Math.sqrt(1. - this.es * s * s);

		}



		p.x=x;

		p.y=y;
@@ -58,16 +88,27 @@ Proj4js.Proj.sinu = { 
		  -----------------*/

		p.x -= this.x0;

		p.y -= this.y0;

		lat = p.y / this.R;

		if (Math.abs(lat) > Proj4js.common.HALF_PI) {

		    Proj4js.reportError("sinu:Inv:DataError");

		}

		temp = Math.abs(lat) - Proj4js.common.HALF_PI;

		if (Math.abs(temp) > Proj4js.common.EPSLN) {

			temp = this.long0+ p.x / (this.R *Math.cos(lat));

			lon = Proj4js.common.adjust_lon(temp);

		lat = p.y / this.a;

		

		if (this.sphere) {

		  

      p.y /= this.C_y;

      lat = this.m ? Math.asin((this.m * p.y + Math.sin(p.y)) / this.n) :

        ( this.n != 1. ? Math.asin(sin(p.y) / this.n) : p.y );

      lon = p.x / (this.C_x * (this.m + Math.cos(p.y)));

		  

		} else {

		  lat = Proj4js.common.pj_inv_mlfn(p.y/this.a, this.es, this.en)

		  var s = Math.abs(lat);

      if (s < Proj4js.common.HALF_PI) {

        s = Math.sin(lat);

        temp = this.long0 + p.x * Math.sqrt(1. - this.es * s * s) /(this.a * Math.cos(lat));

        //temp = this.long0 + p.x / (this.a * Math.cos(lat));

        lon = Proj4js.common.adjust_lon(temp);

      } else if ((s - Proj4js.common.EPSLN) < Proj4js.common.HALF_PI) {

        lon = this.long0;

      }

		  

		}

		  

		p.x=lon;