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https://github.com/csharpee/Map-Projections.git
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36070bf6a8
I started putting in finalised Danseiji datasets. I also added a new input, just for ritual purposes, and also ran the Plotter for the heck of it. My new maps fare surprisingly poorly against established names like Robinson, and even Kavrayskiy. I think I need to rework my metrics slightly. Now, I know how that sounds, but to be fair, the current area metric was designed to ensure Gall-Peters did not beat Behrmann. I made sure it did not pay too much heed to the extremely distorted parts, and paid more attention to the vast moderately-distorted regions. I'm starting to think now, though, that those regions are a lot more important than I'd thought. I'll try to make them as intuitive as possible, while still reasonably conforming to what I think makes a good map.
93 lines
3.3 KiB
Java
93 lines
3.3 KiB
Java
/**
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* MIT License
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*
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* Copyright (c) 2017 Justin Kunimune
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*
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* Permission is hereby granted, free of charge, to any person obtaining a copy
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* of this software and associated documentation files (the "Software"), to deal
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* in the Software without restriction, including without limitation the rights
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* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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* copies of the Software, and to permit persons to whom the Software is
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* furnished to do so, subject to the following conditions:
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*
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* The above copyright notice and this permission notice shall be included in all
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* copies or substantial portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
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* SOFTWARE.
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*/
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package maps;
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import java.util.Arrays;
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import maps.Projection.Property;
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import maps.Projection.Type;
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import utils.Math2;
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import utils.NumericalAnalysis;
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/**
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* A class of values and functions used to approximate the Tobler projection
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*
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* @author jkunimune
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*/
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public class Tobler {
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public static final Projection TOBLER =
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new Projection(
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"Tobler Hyperelliptical", "An equal-area projection shaped like a hyperellipse.",
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2*Math.PI, 0, 0b1001, Type.PSEUDOCYLINDRICAL, Property.EQUAL_AREA, 4,
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new String[]{"Std. Parallel","alpha","K"},
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new double[][] {{0,89,37.5}, {0,1,0.0}, {1,5,3.0}}) { //optimal parameters are 30.6,.50,3.63, but these defaults are more recognizably Tobler
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private static final int N = 20000;
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private double alpha, kappa, epsilon; //epsilon is related to gamma, but defined somewhat differently
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private double[] Z; //Z[i] = sin(phi) when y = i/(Z.length-1)
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public void setParameters(double... params) {
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this.height = 2/Math.pow(Math.cos(Math.toRadians(params[0])),2);
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this.alpha = params[1];
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this.kappa = params[2];
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this.epsilon = NumericalAnalysis.simpsonIntegrate(
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0, 1, this::hyperEllipse, 1./N);
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this.Z = NumericalAnalysis.simpsonODESolve(
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1, N, this::dZdY, 1./N);
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}
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public double[] project(double lat, double lon) {
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final double z0 = Math.abs(Math.sin(lat));
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final int i = Arrays.binarySearch(Z, z0);
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final double y;
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if (i >= 0)
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y = i/(Z.length-1.);
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else if (-i-1 >= Z.length)
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y = Z[Z.length-1];
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else
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y = Math2.linInterp(z0, Z[-i-2], Z[-i-1], -i-2, -i-1)/
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(Z.length-1.);
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return new double[] {
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lon * Math.abs(alpha + (1-alpha)*hyperEllipse(y)),
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y * Math.signum(lat)*height/2 };
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}
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public double[] inverse(double x, double y) {
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return new double[] {
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Math.asin(Z[(int)Math.round(Math.abs(2*y/height)*(Z.length-1))])*Math.signum(y),
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x / Math.abs(alpha + (1-alpha)*hyperEllipse(2*y/height)) };
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}
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public double dZdY(double y) {
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return Math.abs((alpha + (1-alpha)*hyperEllipse(y))/
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(alpha + (1-alpha)*epsilon));
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}
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public double hyperEllipse(double y) {
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return Math.pow(1 - Math.pow(Math.abs(y),kappa), 1/kappa);
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}
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};
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}
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