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-rw-r--r--src/org/unitConverter/math/DecimalComparison.java207
1 files changed, 141 insertions, 66 deletions
diff --git a/src/org/unitConverter/math/DecimalComparison.java b/src/org/unitConverter/math/DecimalComparison.java
index 859e8da..0f5b91e 100644
--- a/src/org/unitConverter/math/DecimalComparison.java
+++ b/src/org/unitConverter/math/DecimalComparison.java
@@ -27,42 +27,45 @@ import java.math.BigDecimal;
*/
public final class DecimalComparison {
/**
- * The value used for double comparison. If two double values are within this value multiplied by the larger value,
- * they are considered equal.
+ * The value used for double comparison. If two double values are within this
+ * value multiplied by the larger value, they are considered equal.
*
* @since 2019-03-18
* @since v0.2.0
*/
public static final double DOUBLE_EPSILON = 1.0e-15;
-
+
/**
- * The value used for float comparison. If two float values are within this value multiplied by the larger value,
- * they are considered equal.
+ * The value used for float comparison. If two float values are within this
+ * value multiplied by the larger value, they are considered equal.
*
* @since 2019-03-18
* @since v0.2.0
*/
public static final float FLOAT_EPSILON = 1.0e-6f;
-
+
/**
* Tests for equality of double values using {@link #DOUBLE_EPSILON}.
* <p>
- * <strong>WARNING: </strong>this method is not technically transitive. If a and b are off by slightly less than
- * {@code epsilon * max(abs(a), abs(b))}, and b and c are off by slightly less than
- * {@code epsilon * max(abs(b), abs(c))}, then equals(a, b) and equals(b, c) will both return true, but equals(a, c)
- * will return false. However, this situation is very unlikely to ever happen in a real programming situation.
+ * <strong>WARNING: </strong>this method is not technically transitive. If a
+ * and b are off by slightly less than {@code epsilon * max(abs(a), abs(b))},
+ * and b and c are off by slightly less than
+ * {@code epsilon * max(abs(b), abs(c))}, then equals(a, b) and equals(b, c)
+ * will both return true, but equals(a, c) will return false. However, this
+ * situation is very unlikely to ever happen in a real programming situation.
* <p>
* If this does become a concern, some ways to solve this problem:
* <ol>
- * <li>Raise the value of epsilon using {@link #equals(double, double, double)} (this does not make a violation of
- * transitivity impossible, it just significantly reduces the chances of it happening)
- * <li>Use {@link BigDecimal} instead of {@code double} (this will make a violation of transitivity 100% impossible)
+ * <li>Raise the value of epsilon using
+ * {@link #equals(double, double, double)} (this does not make a violation of
+ * transitivity impossible, it just significantly reduces the chances of it
+ * happening)
+ * <li>Use {@link BigDecimal} instead of {@code double} (this will make a
+ * violation of transitivity 100% impossible)
* </ol>
*
- * @param a
- * first value to test
- * @param b
- * second value to test
+ * @param a first value to test
+ * @param b second value to test
* @return whether they are equal
* @since 2019-03-18
* @since v0.2.0
@@ -71,57 +74,61 @@ public final class DecimalComparison {
public static final boolean equals(final double a, final double b) {
return DecimalComparison.equals(a, b, DOUBLE_EPSILON);
}
-
+
/**
* Tests for double equality using a custom epsilon value.
*
* <p>
- * <strong>WARNING: </strong>this method is not technically transitive. If a and b are off by slightly less than
- * {@code epsilon * max(abs(a), abs(b))}, and b and c are off by slightly less than
- * {@code epsilon * max(abs(b), abs(c))}, then equals(a, b) and equals(b, c) will both return true, but equals(a, c)
- * will return false. However, this situation is very unlikely to ever happen in a real programming situation.
+ * <strong>WARNING: </strong>this method is not technically transitive. If a
+ * and b are off by slightly less than {@code epsilon * max(abs(a), abs(b))},
+ * and b and c are off by slightly less than
+ * {@code epsilon * max(abs(b), abs(c))}, then equals(a, b) and equals(b, c)
+ * will both return true, but equals(a, c) will return false. However, this
+ * situation is very unlikely to ever happen in a real programming situation.
* <p>
* If this does become a concern, some ways to solve this problem:
* <ol>
- * <li>Raise the value of epsilon (this does not make a violation of transitivity impossible, it just significantly
- * reduces the chances of it happening)
- * <li>Use {@link BigDecimal} instead of {@code double} (this will make a violation of transitivity 100% impossible)
+ * <li>Raise the value of epsilon (this does not make a violation of
+ * transitivity impossible, it just significantly reduces the chances of it
+ * happening)
+ * <li>Use {@link BigDecimal} instead of {@code double} (this will make a
+ * violation of transitivity 100% impossible)
* </ol>
*
- * @param a
- * first value to test
- * @param b
- * second value to test
- * @param epsilon
- * allowed difference
+ * @param a first value to test
+ * @param b second value to test
+ * @param epsilon allowed difference
* @return whether they are equal
* @since 2019-03-18
* @since v0.2.0
*/
- public static final boolean equals(final double a, final double b, final double epsilon) {
+ public static final boolean equals(final double a, final double b,
+ final double epsilon) {
return Math.abs(a - b) <= epsilon * Math.max(Math.abs(a), Math.abs(b));
}
-
+
/**
* Tests for equality of float values using {@link #FLOAT_EPSILON}.
*
* <p>
- * <strong>WARNING: </strong>this method is not technically transitive. If a and b are off by slightly less than
- * {@code epsilon * max(abs(a), abs(b))}, and b and c are off by slightly less than
- * {@code epsilon * max(abs(b), abs(c))}, then equals(a, b) and equals(b, c) will both return true, but equals(a, c)
- * will return false. However, this situation is very unlikely to ever happen in a real programming situation.
+ * <strong>WARNING: </strong>this method is not technically transitive. If a
+ * and b are off by slightly less than {@code epsilon * max(abs(a), abs(b))},
+ * and b and c are off by slightly less than
+ * {@code epsilon * max(abs(b), abs(c))}, then equals(a, b) and equals(b, c)
+ * will both return true, but equals(a, c) will return false. However, this
+ * situation is very unlikely to ever happen in a real programming situation.
* <p>
* If this does become a concern, some ways to solve this problem:
* <ol>
- * <li>Raise the value of epsilon using {@link #equals(float, float, float)} (this does not make a violation of
- * transitivity impossible, it just significantly reduces the chances of it happening)
- * <li>Use {@link BigDecimal} instead of {@code float} (this will make a violation of transitivity 100% impossible)
+ * <li>Raise the value of epsilon using {@link #equals(float, float, float)}
+ * (this does not make a violation of transitivity impossible, it just
+ * significantly reduces the chances of it happening)
+ * <li>Use {@link BigDecimal} instead of {@code float} (this will make a
+ * violation of transitivity 100% impossible)
* </ol>
*
- * @param a
- * first value to test
- * @param b
- * second value to test
+ * @param a first value to test
+ * @param b second value to test
* @return whether they are equal
* @since 2019-03-18
* @since v0.2.0
@@ -129,53 +136,121 @@ public final class DecimalComparison {
public static final boolean equals(final float a, final float b) {
return DecimalComparison.equals(a, b, FLOAT_EPSILON);
}
-
+
/**
* Tests for float equality using a custom epsilon value.
*
* <p>
- * <strong>WARNING: </strong>this method is not technically transitive. If a and b are off by slightly less than
- * {@code epsilon * max(abs(a), abs(b))}, and b and c are off by slightly less than
- * {@code epsilon * max(abs(b), abs(c))}, then equals(a, b) and equals(b, c) will both return true, but equals(a, c)
- * will return false. However, this situation is very unlikely to ever happen in a real programming situation.
+ * <strong>WARNING: </strong>this method is not technically transitive. If a
+ * and b are off by slightly less than {@code epsilon * max(abs(a), abs(b))},
+ * and b and c are off by slightly less than
+ * {@code epsilon * max(abs(b), abs(c))}, then equals(a, b) and equals(b, c)
+ * will both return true, but equals(a, c) will return false. However, this
+ * situation is very unlikely to ever happen in a real programming situation.
* <p>
* If this does become a concern, some ways to solve this problem:
* <ol>
- * <li>Raise the value of epsilon (this does not make a violation of transitivity impossible, it just significantly
- * reduces the chances of it happening)
- * <li>Use {@link BigDecimal} instead of {@code float} (this will make a violation of transitivity 100% impossible)
+ * <li>Raise the value of epsilon (this does not make a violation of
+ * transitivity impossible, it just significantly reduces the chances of it
+ * happening)
+ * <li>Use {@link BigDecimal} instead of {@code float} (this will make a
+ * violation of transitivity 100% impossible)
* </ol>
*
- * @param a
- * first value to test
- * @param b
- * second value to test
- * @param epsilon
- * allowed difference
+ * @param a first value to test
+ * @param b second value to test
+ * @param epsilon allowed difference
* @return whether they are equal
* @since 2019-03-18
* @since v0.2.0
*/
- public static final boolean equals(final float a, final float b, final float epsilon) {
+ public static final boolean equals(final float a, final float b,
+ final float epsilon) {
return Math.abs(a - b) <= epsilon * Math.max(Math.abs(a), Math.abs(b));
}
-
+
+ /**
+ * Tests for equality of {@code UncertainDouble} values using
+ * {@link #DOUBLE_EPSILON}.
+ * <p>
+ * <strong>WARNING: </strong>this method is not technically transitive. If a
+ * and b are off by slightly less than {@code epsilon * max(abs(a), abs(b))},
+ * and b and c are off by slightly less than
+ * {@code epsilon * max(abs(b), abs(c))}, then equals(a, b) and equals(b, c)
+ * will both return true, but equals(a, c) will return false. However, this
+ * situation is very unlikely to ever happen in a real programming situation.
+ * <p>
+ * If this does become a concern, some ways to solve this problem:
+ * <ol>
+ * <li>Raise the value of epsilon using
+ * {@link #equals(UncertainDouble, UncertainDouble, double)} (this does not
+ * make a violation of transitivity impossible, it just significantly reduces
+ * the chances of it happening)
+ * <li>Use {@link BigDecimal} instead of {@code double} (this will make a
+ * violation of transitivity 100% impossible)
+ * </ol>
+ *
+ * @param a first value to test
+ * @param b second value to test
+ * @return whether they are equal
+ * @since 2020-09-07
+ * @see #hashCode(double)
+ */
+ public static final boolean equals(final UncertainDouble a,
+ final UncertainDouble b) {
+ return DecimalComparison.equals(a.value(), b.value())
+ && DecimalComparison.equals(a.uncertainty(), b.uncertainty());
+ }
+
+ /**
+ * Tests for {@code UncertainDouble} equality using a custom epsilon value.
+ *
+ * <p>
+ * <strong>WARNING: </strong>this method is not technically transitive. If a
+ * and b are off by slightly less than {@code epsilon * max(abs(a), abs(b))},
+ * and b and c are off by slightly less than
+ * {@code epsilon * max(abs(b), abs(c))}, then equals(a, b) and equals(b, c)
+ * will both return true, but equals(a, c) will return false. However, this
+ * situation is very unlikely to ever happen in a real programming situation.
+ * <p>
+ * If this does become a concern, some ways to solve this problem:
+ * <ol>
+ * <li>Raise the value of epsilon (this does not make a violation of
+ * transitivity impossible, it just significantly reduces the chances of it
+ * happening)
+ * <li>Use {@link BigDecimal} instead of {@code double} (this will make a
+ * violation of transitivity 100% impossible)
+ * </ol>
+ *
+ * @param a first value to test
+ * @param b second value to test
+ * @param epsilon allowed difference
+ * @return whether they are equal
+ * @since 2019-03-18
+ * @since v0.2.0
+ */
+ public static final boolean equals(final UncertainDouble a,
+ final UncertainDouble b, final double epsilon) {
+ return DecimalComparison.equals(a.value(), b.value(), epsilon)
+ && DecimalComparison.equals(a.uncertainty(), b.uncertainty(),
+ epsilon);
+ }
+
/**
- * Takes the hash code of doubles. Values that are equal according to {@link #equals(double, double)} will have the
- * same hash code.
+ * Takes the hash code of doubles. Values that are equal according to
+ * {@link #equals(double, double)} will have the same hash code.
*
- * @param d
- * double to hash
+ * @param d double to hash
* @return hash code of double
* @since 2019-10-16
*/
public static final int hash(final double d) {
return Float.hashCode((float) d);
}
-
+
// You may NOT get any DecimalComparison instances
private DecimalComparison() {
throw new AssertionError();
}
-
+
}