Plotter improvements
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serso
parent
a49ca358af
commit
600b454eef
@ -406,6 +406,7 @@ public class CalculatorPlotFragment extends SherlockFragment implements Calculat
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}
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return new CubicLineChart(data, renderer, 0.1f);
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//return new ScatterChart(data, renderer);
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}
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private static XYSeriesRenderer createImagRenderer() {
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@ -473,7 +474,7 @@ public class CalculatorPlotFragment extends SherlockFragment implements Calculat
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private static XYSeriesRenderer createCommonRenderer() {
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final XYSeriesRenderer renderer = new XYSeriesRenderer();
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renderer.setFillPoints(true);
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renderer.setPointStyle(PointStyle.POINT);
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renderer.setPointStyle(PointStyle.CIRCLE);
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renderer.setLineWidth(3);
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renderer.setColor(Color.WHITE);
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renderer.setStroke(BasicStroke.SOLID);
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@ -6,6 +6,7 @@
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package org.solovyev.android.calculator.plot;
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import android.util.Log;
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import jscl.math.Expression;
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import jscl.math.Generic;
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import jscl.math.JsclInteger;
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@ -25,7 +26,8 @@ import org.jetbrains.annotations.Nullable;
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*/
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public final class PlotUtils {
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private static final double MAX_Y_DIFF = Math.pow(10, 6);
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private static final double MAX_Y_DIFF = 1;
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private static final double MAX_X_DIFF = 1;
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// not intended for instantiation
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private PlotUtils() {
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@ -51,80 +53,261 @@ public final class PlotUtils {
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max = max + dist;
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}
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final double step = Math.max( dist / numberOfSteps, 0.000000001);
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final double eps = 0.000000001;
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Double prevRealY = null;
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Double prevX = null;
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Double prevImagY = null;
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final double defaultStep = Math.max(dist / numberOfSteps, eps);
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double step = defaultStep;
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final Point real = new Point();
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final Point imag = new Point();
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double x = min;
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while (x <= max) {
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boolean needToCalculateRealY = realSeries.needToAdd(step, x);
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while (x <= max) {
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boolean needToCalculateRealY = realSeries.needToAdd(eps, x);
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if (needToCalculateRealY) {
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final Complex c = calculatorExpression(expression, variable, x);
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Double y = prepareY(c.realPart());
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if (y != null) {
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addSingularityPoint(realSeries, prevX, x, prevRealY, y);
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if (y != null) {
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real.moveToNextPoint(x, y);
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addSingularityPoint(realSeries, real);
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realSeries.add(x, y);
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prevRealY = y;
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prevX = x;
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}
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boolean needToCalculateImagY = imagSeries != null && imagSeries.needToAdd(step, x);
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boolean needToCalculateImagY = imagSeries != null && imagSeries.needToAdd(eps, x);
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if (needToCalculateImagY) {
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y = prepareY(c.imaginaryPart());
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if (y != null) {
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addSingularityPoint(imagSeries, prevX, x, prevImagY, y);
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imag.moveToNextPoint(x, y);
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addSingularityPoint(imagSeries, imag);
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imagSeries.add(x, y);
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prevImagY = y;
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prevX = x;
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}
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}
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if (c.imaginaryPart() != 0d) {
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imagExists = true;
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}
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}
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} else {
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boolean needToCalculateImagY = imagSeries != null && imagSeries.needToAdd(step, x);
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boolean needToCalculateImagY = imagSeries != null && imagSeries.needToAdd(eps, x);
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if (needToCalculateImagY) {
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final Complex c = calculatorExpression(expression, variable, x);
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Double y = prepareY(c.imaginaryPart());
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if (y != null) {
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addSingularityPoint(imagSeries, prevX, x, prevImagY, y);
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imag.moveToNextPoint(x, y);
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addSingularityPoint(imagSeries, imag);
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imagSeries.add(x, y);
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prevImagY = y;
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prevX = x;
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}
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}
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if (c.imaginaryPart() != 0d) {
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imagExists = true;
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}
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}
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}
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x += step;
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}
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step = updateStep(real, step, defaultStep / 2);
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if (real.isX2Defined()) {
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x = real.getX2() + step;
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} else {
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x += step;
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}
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}
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return imagExists;
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}
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@NotNull
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private static class Point {
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private static final double DEFAULT = Double.MIN_VALUE;
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private double x0 = DEFAULT;
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private double x1 = DEFAULT;
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private double x2 = DEFAULT;
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private double y0 = DEFAULT;
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private double y1 = DEFAULT;
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private double y2 = DEFAULT;
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private Point() {
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}
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public void moveToNextPoint(double x, double y) {
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if ( this.x2 == x ) {
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return;
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}
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this.x0 = this.x1;
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this.x1 = this.x2;
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this.x2 = x;
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this.y0 = this.y1;
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this.y1 = this.y2;
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this.y2 = y;
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}
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public boolean isFullyDefined() {
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return x0 != DEFAULT && x1 != DEFAULT && x2 != DEFAULT && y0 != DEFAULT && y1 != DEFAULT && y2 != DEFAULT;
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}
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public double getDx2() {
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return x2 - x1;
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}
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public double getAbsDx2() {
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if ( x2 > x1 ) {
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return Math.abs(x2 - x1);
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} else {
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return Math.abs(x1 - x2);
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}
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}
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public double getAbsDx1() {
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if ( x1 > x0 ) {
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return Math.abs(x1 - x0);
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} else {
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return Math.abs(x0 - x1);
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}
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}
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public double getAbsDy1() {
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if ( y1 > y0 ) {
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return Math.abs(y1 - y0);
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} else {
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return Math.abs(y0 - y1);
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}
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}
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public double getAbsDy2() {
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if ( y2 > y1 ) {
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return Math.abs(y2 - y1);
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} else {
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return Math.abs(y1 - y2);
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}
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}
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public double getX0() {
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return x0;
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}
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public double getX1() {
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return x1;
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}
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public double getX2() {
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return x2;
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}
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public boolean isX2Defined() {
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return x2 != DEFAULT;
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}
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public double getY0() {
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return y0;
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}
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public double getY1() {
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return y1;
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}
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public double getY2() {
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return y2;
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}
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public void clearHistory () {
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this.x0 = DEFAULT;
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this.x1 = DEFAULT;
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this.y0 = DEFAULT;
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this.y1 = DEFAULT;
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}
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public double getAbsDyDx2() {
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double dx2 = this.getAbsDx2();
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double dy2 = this.getAbsDy2();
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return dy2 / dx2;
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}
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public double getAbsDyDx1() {
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double dx1 = this.getAbsDx1();
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double dy1 = this.getAbsDy1();
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return dy1 / dx1;
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}
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public double getDyDx1() {
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double result = getAbsDyDx1();
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return y1 > y0 ? result : -result;
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}
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public double getDyDx2() {
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double result = getAbsDyDx2();
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return y2 > y1 ? result : -result;
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}
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@Override
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public String toString() {
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return "Point{" +
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"x0=" + x0 +
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", x1=" + x1 +
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", x2=" + x2 +
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", y0=" + y0 +
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", y1=" + y1 +
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", y2=" + y2 +
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'}';
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}
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}
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private static double updateStep(@NotNull Point real,
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double step,
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double eps) {
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if ( !real.isFullyDefined() ) {
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return step;
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} else {
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double dydx2 = real.getAbsDyDx2();
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double dydx1 = real.getAbsDyDx1();
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double k = dydx2 / dydx1;
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if ( k > 1 ) {
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step = step / k;
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} else if ( k > 0 ) {
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step = step * k;
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}
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return Math.max(step, eps);
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}
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}
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@NotNull
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public static Complex calculatorExpression(@NotNull Generic expression, @NotNull Constant variable, double x) {
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return unwrap(expression.substitute(variable, Expression.valueOf(x)).numeric());
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}
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public static void addSingularityPoint(@NotNull MyXYSeries series, @Nullable Double prevX, @NotNull Double x, @Nullable Double prevY, @NotNull Double y) {
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if (prevX != null && prevY != null) {
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public static void addSingularityPoint(@NotNull MyXYSeries series,
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@NotNull Point point) {
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if (point.isFullyDefined()) {
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// y or prevY should be more than 1d because if they are too small false singularity may occur (e.g., 1/0.000000000000000001)
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if ( (Math.abs(y) >= 1d && Math.abs(prevY / y) > MAX_Y_DIFF) || (Math.abs(prevY) >= 1d && Math.abs(y / prevY) > MAX_Y_DIFF)) {
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//Log.d(CalculatorPlotActivity.class.getName(), "Singularity! Prev point: (" + prevX + ", " + prevY + "), current point: (" +x+ ", " + y +")" );
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// double dy0 = y1 - y0;
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// double dx0 = x1 - x0;
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// double dydx0 = dy0 / dx0;
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double dy2 = point.getAbsDy2();
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double dx2 = point.getAbsDx2();
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//double dx1 = x2 - x1;
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// double dydx1 = dy2 / dx1;
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if ( dy2 > MAX_Y_DIFF && dx2 < MAX_X_DIFF && isDifferentSign(point.getY2(), point.getY1()) && isDifferentSign(point.getDyDx1(), point.getDyDx2())) {
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Log.d(CalculatorPlotActivity.class.getName(), "Singularity: " + point);
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//Log.d(CalculatorPlotActivity.class.getName(), String.valueOf(prevX + Math.abs(x - prevX) / 2) + ", null");
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series.add(prevX + Math.abs(x - prevX) / 2, MathHelper.NULL_VALUE);
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series.add(point.getX1() + point.getAbsDx2() / 2, MathHelper.NULL_VALUE);
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point.clearHistory();
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}
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}
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}
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@Nullable
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private static boolean isDifferentSign(@NotNull Double y0, @NotNull Double y1) {
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return (y0 >= 0 && y1 < 0) || (y1 >= 0 && y0 < 0);
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}
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@Nullable
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public static Double prepareY(double y) {
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if (Double.isNaN(y)) {
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return null;
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