fit.ScientificDouble Maven / Gradle / Ivy

Go to download

Show more of this group Show more artifacts with this name
Show all versions of fitnesse Show documentation

The fully integrated standalone wiki, and acceptance testing framework.

There is a newer version: 20181217

// Modified or written by Object Mentor, Inc. for inclusion with FitNesse.
// Copyright (c) 2002 Cunningham & Cunningham, Inc.
// Released under the terms of the GNU General Public License version 2 or later.
package fit;

// Copyright (c) 2002 Cunningham & Cunningham, Inc.
// Released under the terms of the GNU General Public License version 2 or later.

// Warning: not (yet) a general number usable in all calculations.

public class ScientificDouble extends Number implements Comparable {
  private static final long serialVersionUID = 1L;

  protected final double value;
  protected double precision;

  public ScientificDouble(double value) {
    this.value = value;
    this.precision = 0;
  }

  public static ScientificDouble valueOf(String s) {
    ScientificDouble result = new ScientificDouble(Double.parseDouble(s));
    result.precision = precision(s);
    return result;
  }

  public static ScientificDouble parse(String s) {
    return valueOf(s);
  }

  public static double precision(String s) {
    double value = Double.parseDouble(s);
    double bound = Double.parseDouble(tweak(s.trim()));
    return Math.abs(bound - value);
  }

  public static String tweak(String s) {
    int pos;
    if ((pos = s.toLowerCase().indexOf("e")) >= 0) {
      return tweak(s.substring(0, pos)) + s.substring(pos);
    }
    if (s.contains(".")) {
      return s + "5";
    }
    return s + ".5";
  }

  @Override
  public boolean equals(Object obj) {
    return obj != null && obj instanceof Number && compareTo((Number) obj) == 0;
  }

  @Override
  public int hashCode() {
    return (int) value;
  }

  @Override
  public int compareTo(Number obj) {
    double other = obj.doubleValue();
    double diff = value - other;
    if (diff < -precision) return -1;
    if (diff > precision) return 1;
    if (Double.isNaN(value) && Double.isNaN(other)) return 0;
    if (Double.isNaN(value)) return 1;
    if (Double.isNaN(other)) return -1;
    return 0;
  }

  @Override
  public String toString() {
    return Double.toString(value);
  }

  @Override
  public double doubleValue() {
    return value;
  }

  @Override
  public float floatValue() {
    return (float) value;
  }

  @Override
  public long longValue() {
    return (long) value;
  }

  @Override
  public int intValue() {
    return (int) value;
  }
}