aherbert commented on code in PR #348:
URL: https://github.com/apache/commons-math/pull/348#discussion_r4459279258
##########
commons-math-legacy-core/src/main/java/org/apache/commons/math4/legacy/core/MathArrays.java:
##########
@@ -273,14 +276,17 @@ public static double distanceInf(double[] p1, double[]
p2) {
*
* @param p1 the first point
* @param p2 the second point
- * @return the L<sub>∞</sub> distance between the two points
+ * @return the L<sub>∞</sub> distance between the two points, or
+ * {@link Integer#MAX_VALUE} if the distance is too large to be
+ * represented as an {@code int}
* @throws DimensionMismatchException if the array lengths differ.
*/
public static int distanceInf(int[] p1, int[] p2) {
checkEqualLength(p1, p2);
int max = 0;
for (int i = 0; i < p1.length; i++) {
- max = JdkMath.max(max, JdkMath.abs(p1[i] - p2[i]));
+ final long delta = JdkMath.abs((long) p1[i] - p2[i]);
+ max = (int) JdkMath.min(JdkMath.max(max, delta),
Integer.MAX_VALUE);
Review Comment:
Compute max as a long and then convert to int after the loop for the return
##########
commons-math-legacy-core/src/main/java/org/apache/commons/math4/legacy/core/MathArrays.java:
##########
@@ -203,14 +203,17 @@ public static double distance1(double[] p1, double[] p2) {
*
* @param p1 the first point
* @param p2 the second point
- * @return the L<sub>1</sub> distance between the two points
+ * @return the L<sub>1</sub> distance between the two points, or
+ * {@link Integer#MAX_VALUE} if the distance is too large to be
+ * represented as an {@code int}
* @throws DimensionMismatchException if the array lengths differ.
*/
public static int distance1(int[] p1, int[] p2) {
checkEqualLength(p1, p2);
int sum = 0;
for (int i = 0; i < p1.length; i++) {
- sum += JdkMath.abs(p1[i] - p2[i]);
+ final long delta = JdkMath.abs((long) p1[i] - p2[i]);
Review Comment:
Compute sum as a long. Then do a final check against MAX_VALUE after the
loop on the return.
The sum cannot overflow a long as two max length arrays with MIN in one and
MAX in the other is (2^31-1) * (2^32-1) < 2^63.
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