mirror of
https://github.com/csharpee/Map-Projections.git
synced 2025-12-12 00:00:17 -05:00
ea02e8a2ef
I made a program to automatically generate HTML snippets to fill the projection page in my GH-Pages branch. It also automatically produces nice pictures to go with it. I also threw in a nifty new transverse feature, primarily for azimuthal maps. And I now represent properties and types as enums. And I fixed a bug in 2 point equidistant. And fixed some unicode issues.
93 lines
3.2 KiB
Java
93 lines
3.2 KiB
Java
/**
|
|
* MIT License
|
|
*
|
|
* Copyright (c) 2017 Justin Kunimune
|
|
*
|
|
* Permission is hereby granted, free of charge, to any person obtaining a copy
|
|
* of this software and associated documentation files (the "Software"), to deal
|
|
* in the Software without restriction, including without limitation the rights
|
|
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
|
|
* copies of the Software, and to permit persons to whom the Software is
|
|
* furnished to do so, subject to the following conditions:
|
|
*
|
|
* The above copyright notice and this permission notice shall be included in all
|
|
* copies or substantial portions of the Software.
|
|
*
|
|
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
|
|
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
|
|
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
|
|
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
|
|
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
|
|
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
|
|
* SOFTWARE.
|
|
*/
|
|
package maps;
|
|
|
|
import java.util.Arrays;
|
|
|
|
import maps.Projection.Property;
|
|
import maps.Projection.Type;
|
|
import utils.Math2;
|
|
import utils.NumericalAnalysis;
|
|
|
|
/**
|
|
* A class of values and functions used to approximate the Tobler projection
|
|
*
|
|
* @author jkunimune
|
|
*/
|
|
public class Tobler {
|
|
|
|
public static final Projection TOBLER =
|
|
new Projection(
|
|
"Tobler", "An equal-area projection shaped like a hyperellipse (in case you're wondering about gamma, it's calculated automatically)",
|
|
2., 0b1001, Type.PSEUDOCYLINDRICAL, Property.EQUAL_AREA,
|
|
new String[]{"Std. Parallel","alpha","K"},
|
|
new double[][] {{0,89,37.5}, {0,1,0}, {1,8,2.5}}) {
|
|
|
|
private static final int N = 10000;
|
|
private double alpha, kappa, epsilon; //epsilon is related to gamma, but defined somewhat differently
|
|
private double[] Z; //Z[i] = sin(phi) when y = i/(Z.length-1)
|
|
|
|
public void setParameters(double... params) {
|
|
this.aspectRatio = Math.pow(Math.cos(Math.toRadians(params[0])),2)*Math.PI;
|
|
this.alpha = params[1];
|
|
this.kappa = params[2];
|
|
this.epsilon = NumericalAnalysis.simpsonIntegrate(
|
|
0, 1, this::hyperEllipse, 1./N);
|
|
this.Z = NumericalAnalysis.simpsonODESolve(
|
|
1, N, this::dZdY, 1./N);
|
|
}
|
|
|
|
public double[] project(double lat, double lon) {
|
|
final double z0 = Math.abs(Math.sin(lat));
|
|
final int i = Arrays.binarySearch(Z, z0);
|
|
final double y;
|
|
if (i >= 0)
|
|
y = i/(Z.length-1.);
|
|
else if (-i-1 >= Z.length)
|
|
y = Z[Z.length-1];
|
|
else
|
|
y = Math2.linInterp(z0, Z[-i-2], Z[-i-1], -i-2, -i-1)/
|
|
(Z.length-1.);
|
|
return new double[] {
|
|
lon * Math.abs(alpha + (1-alpha)*hyperEllipse(y)),
|
|
y * Math.signum(lat)/aspectRatio*Math.PI };
|
|
}
|
|
|
|
public double[] inverse(double x, double y) {
|
|
return new double[] {
|
|
Math.asin(Z[(int)Math.round(Math.abs(y)*(Z.length-1))])*Math.signum(y),
|
|
Math.PI * x / Math.abs(alpha + (1-alpha)*hyperEllipse(y)) };
|
|
}
|
|
|
|
public double dZdY(double y) {
|
|
return Math.abs((alpha + (1-alpha)*hyperEllipse(y))/
|
|
(alpha + (1-alpha)*epsilon));
|
|
}
|
|
|
|
public double hyperEllipse(double y) {
|
|
return Math.pow(1 - Math.pow(Math.abs(y),kappa), 1/kappa);
|
|
}
|
|
};
|
|
}
|