Correct verification of zero length values and weights
This bug was found when checking the sonar report for the variance class
which uses MathArrays.verifyValues.
diff --git a/commons-math-legacy-core/src/main/java/org/apache/commons/math4/legacy/core/MathArrays.java b/commons-math-legacy-core/src/main/java/org/apache/commons/math4/legacy/core/MathArrays.java
index 00d3c48..d92362b 100644
--- a/commons-math-legacy-core/src/main/java/org/apache/commons/math4/legacy/core/MathArrays.java
+++ b/commons-math-legacy-core/src/main/java/org/apache/commons/math4/legacy/core/MathArrays.java
@@ -968,6 +968,7 @@
* <li>the weights array contains one or more infinite values</li>
* <li>the weights array contains one or more NaN values</li>
* <li>the weights array contains negative values</li>
+ * <li>the weights array does not contain at least one non-zero value (applies when length is non zero)</li>
* <li>the start and length arguments do not determine a valid array</li></ul>
* </li>
* <li>returns <code>false</code> if the array is non-null, but
@@ -1004,6 +1005,7 @@
* <li>the weights array contains one or more infinite values</li>
* <li>the weights array contains one or more NaN values</li>
* <li>the weights array contains negative values</li>
+ * <li>the weights array does not contain at least one non-zero value (applies when length is non zero)</li>
* <li>the start and length arguments do not determine a valid array</li></ul>
* </li>
* <li>returns <code>false</code> if the array is non-null, but
@@ -1031,27 +1033,29 @@
checkEqualLength(weights, values);
- boolean containsPositiveWeight = false;
- for (int i = begin; i < begin + length; i++) {
- final double weight = weights[i];
- if (Double.isNaN(weight)) {
- throw new MathIllegalArgumentException(LocalizedFormats.NAN_ELEMENT_AT_INDEX, Integer.valueOf(i));
+ if (length != 0) {
+ boolean containsPositiveWeight = false;
+ for (int i = begin; i < begin + length; i++) {
+ final double weight = weights[i];
+ if (Double.isNaN(weight)) {
+ throw new MathIllegalArgumentException(LocalizedFormats.NAN_ELEMENT_AT_INDEX, Integer.valueOf(i));
+ }
+ if (Double.isInfinite(weight)) {
+ throw new MathIllegalArgumentException(LocalizedFormats.INFINITE_ARRAY_ELEMENT,
+ Double.valueOf(weight), Integer.valueOf(i));
+ }
+ if (weight < 0) {
+ throw new MathIllegalArgumentException(LocalizedFormats.NEGATIVE_ELEMENT_AT_INDEX,
+ Integer.valueOf(i), Double.valueOf(weight));
+ }
+ if (!containsPositiveWeight && weight > 0.0) {
+ containsPositiveWeight = true;
+ }
}
- if (Double.isInfinite(weight)) {
- throw new MathIllegalArgumentException(LocalizedFormats.INFINITE_ARRAY_ELEMENT,
- Double.valueOf(weight), Integer.valueOf(i));
- }
- if (weight < 0) {
- throw new MathIllegalArgumentException(LocalizedFormats.NEGATIVE_ELEMENT_AT_INDEX,
- Integer.valueOf(i), Double.valueOf(weight));
- }
- if (!containsPositiveWeight && weight > 0.0) {
- containsPositiveWeight = true;
- }
- }
- if (!containsPositiveWeight) {
- throw new MathIllegalArgumentException(LocalizedFormats.WEIGHT_AT_LEAST_ONE_NON_ZERO);
+ if (!containsPositiveWeight) {
+ throw new MathIllegalArgumentException(LocalizedFormats.WEIGHT_AT_LEAST_ONE_NON_ZERO);
+ }
}
return verifyValues(values, begin, length, allowEmpty);
diff --git a/commons-math-legacy-core/src/test/java/org/apache/commons/math4/legacy/core/MathArraysTest.java b/commons-math-legacy-core/src/test/java/org/apache/commons/math4/legacy/core/MathArraysTest.java
index 84b7fc5..aa71a74 100644
--- a/commons-math-legacy-core/src/test/java/org/apache/commons/math4/legacy/core/MathArraysTest.java
+++ b/commons-math-legacy-core/src/test/java/org/apache/commons/math4/legacy/core/MathArraysTest.java
@@ -635,6 +635,9 @@
final double[] nullArray = null;
Assert.assertFalse(MathArrays.verifyValues(singletonArray, 0, 0));
Assert.assertFalse(MathArrays.verifyValues(testArray, 0, 0));
+ Assert.assertTrue(MathArrays.verifyValues(testArray, 0, 0, true));
+ Assert.assertFalse(MathArrays.verifyValues(testArray, testWeightsArray, 0, 0));
+ Assert.assertTrue(MathArrays.verifyValues(testArray, testWeightsArray, 0, 0, true));
try {
MathArrays.verifyValues(singletonArray, 2, 1); // start past end
Assert.fail("Expecting MathIllegalArgumentException");
@@ -683,6 +686,12 @@
} catch (MathIllegalArgumentException ex) {
// expected
}
+ try {
+ MathArrays.verifyValues(testArray, new double[testArray.length], 0, 6); // can't have all zero weights
+ Assert.fail("Expecting MathIllegalArgumentException");
+ } catch (MathIllegalArgumentException ex) {
+ // expected
+ }
}
@Test
