jodd-core/src/main/java/jodd/util/ArraysUtil.java
public static int indexOf(double[] array, double[] sub, int startIndex, int endIndex) {
		int sublen = sub.length;
		if (sublen == 0) {
			return startIndex;
		}
		int total = endIndex - sublen + 1;
		double c = sub[0];
		mainloop:
		for (int i = startIndex; i < total; i++) {
			if (Double.compare(array[i], c) != 0) {
				continue;
			}
			int j = 1;
			int k = i + 1;
			while (j < sublen) {
				if (Double.compare(sub[j], array[k]) != 0) {
					continue mainloop;
				}
				j++; k++;
			}
			return i;
		}
		return -1;
	}
public static int indexOf(double[] array, double[] sub, int startIndex, int endIndex) {
		int sublen = sub.length;
		if (sublen == 0) {
			return startIndex;
		}
		int total = endIndex - sublen + 1;
		double c = sub[0];
		mainloop:
		for (int i = startIndex; i < total; i++) {
			if (Double.compare(array[i], c) != 0) {
				continue;
			}
			int j = 1;
			int k = i + 1;
			while (j < sublen) {
				if (Double.compare(sub[j], array[k]) != 0) {
					continue mainloop;
				}
				j++; k++;
			}
			return i;
		}
		return -1;
	}
Finds the first occurrence in an array from specified given position and upto given length.