From 8dc523faab4899942ff49eae3f6af8dcee4912ee Mon Sep 17 00:00:00 2001
From: Peter Powers <pmpowers@usgs.gov>
Date: Wed, 12 Apr 2017 09:11:39 -0600
Subject: [PATCH] added trim() to XySequence
---
src/org/opensha2/data/Data.java | 18 ++++++++++++++++++
src/org/opensha2/data/ImmutableXySequence.java | 11 +++++++++++
src/org/opensha2/data/XySequence.java | 10 ++++++++++
3 files changed, 39 insertions(+)
diff --git a/src/org/opensha2/data/Data.java b/src/org/opensha2/data/Data.java
index b32430b3d..8a074a39f 100644
--- a/src/org/opensha2/data/Data.java
+++ b/src/org/opensha2/data/Data.java
@@ -1447,4 +1447,22 @@ public final class Data {
// checkArgument(expression, "value");
// }
+ static int firstNonZeroIndex(double... data) {
+ for (int i=0; i<data.length; i++) {
+ if (data[i] != 0.0) {
+ return i;
+ }
+ }
+ return -1;
+ }
+
+ static int lastNonZeroIndex(double... data) {
+ for (int i=data.length-1; i>=0; i--) {
+ if (data[i] != 0.0) {
+ return i;
+ }
+ }
+ return -1;
+ }
+
}
diff --git a/src/org/opensha2/data/ImmutableXySequence.java b/src/org/opensha2/data/ImmutableXySequence.java
index 7781dec7c..f3d8f96a4 100644
--- a/src/org/opensha2/data/ImmutableXySequence.java
+++ b/src/org/opensha2/data/ImmutableXySequence.java
@@ -2,6 +2,7 @@ package org.opensha2.data;
import static com.google.common.base.Preconditions.checkArgument;
import static com.google.common.base.Preconditions.checkElementIndex;
+import static com.google.common.base.Preconditions.checkState;
import java.util.Arrays;
@@ -65,6 +66,16 @@ class ImmutableXySequence extends XySequence {
public final boolean isClear() {
return Data.areZeroValued(ys);
}
+
+ @Override
+ public final XySequence trim() {
+ checkState(!this.isClear(), "XySequence.trim() not permitted for 'clear' sequences");
+ int minIndex = Data.firstNonZeroIndex(ys);
+ int maxIndex = Data.lastNonZeroIndex(ys) + 1;
+ return new ImmutableXySequence(
+ Arrays.copyOfRange(xs, minIndex, maxIndex),
+ Arrays.copyOfRange(ys, minIndex, maxIndex));
+ }
@Override
public final boolean equals(Object obj) {
diff --git a/src/org/opensha2/data/XySequence.java b/src/org/opensha2/data/XySequence.java
index a58ea154f..0ed827b98 100644
--- a/src/org/opensha2/data/XySequence.java
+++ b/src/org/opensha2/data/XySequence.java
@@ -506,6 +506,16 @@ public abstract class XySequence implements Iterable<XyPoint> {
*/
public abstract boolean isClear();
+ /**
+ * Returns a new, immutable sequence that has had all leading and trailing
+ * zero-valued points ({@code y = 0}) removed. Any zero-valued points in the
+ * middle of this sequence are ignored.
+ *
+ * @throws IllegalStateException if {@link #isClear() this.isClear()} as empty
+ * sequences are not permitted
+ */
+ public abstract XySequence trim();
+
/**
* Transforms all y-values in place using the supplied {@link Function}.
*
--
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