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+/*
+ * Copyright 2009 Phil Burk, Mobileer Inc
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.jsyn.data;
+
+public class HammingWindow implements SpectralWindow {
+ private double[] data;
+
+ /** Construct a generalized Hamming Window */
+ public HammingWindow(int length, double alpha, double beta) {
+ data = new double[length];
+ double scaler = 2.0 * Math.PI / (length - 1);
+ for (int i = 0; i < length; i++) {
+ data[i] = alpha - (beta * (Math.cos(i * scaler)));
+ }
+ }
+
+ /** Traditional Hamming Window with alpha = 25/46 and beta = 21/46 */
+ public HammingWindow(int length) {
+ this(length, 25.0 / 46.0, 21.0 / 46.0);
+ }
+
+ @Override
+ public double get(int index) {
+ return data[index];
+ }
+
+}