Java Code Examples for cern.colt.list.DoubleArrayList#get()

/**
 * Computes the specified quantile elements over the values previously added.
 * @param phis the quantiles for which elements are to be computed. Each phi must be in the interval (0.0,1.0]. <tt>phis</tt> must be sorted ascending.
 * @return the approximate quantile elements.
 */
public DoubleArrayList quantileElements(DoubleArrayList phis) {
	if (precomputeEpsilon<=0.0) return super.quantileElements(phis);
	
	int quantilesToPrecompute = (int) Utils.epsilonCeiling(1.0 / precomputeEpsilon);
	/*
	if (phis.size() > quantilesToPrecompute) {
		// illegal use case!
		// we compute results, but loose explicit approximation guarantees.
		return super.quantileElements(phis);
	}
	*/
 
	//select that quantile from the precomputed set that corresponds to a position closest to phi.
	phis = phis.copy();
	double e = precomputeEpsilon;
	for (int index=phis.size(); --index >= 0;) {
		double phi = phis.get(index);
		int i = (int) Math.round( ((2.0*phi/e) - 1.0 ) / 2.0); // finds closest
		i = Math.min(quantilesToPrecompute-1, Math.max(0,i));
		double augmentedPhi = (e/2.0)*(1+2*i);
		phis.set(index,augmentedPhi);				
	}
	
	return super.quantileElements(phis);
}
 

/**
 * Returns a string representation of the receiver, containing
 * the String representation of each key-value pair, sorted ascending by key.
 */
public String toString() {
	DoubleArrayList theKeys = keys();
	theKeys.sort();

	StringBuffer buf = new StringBuffer();
	buf.append("[");
	int maxIndex = theKeys.size() - 1;
	for (int i = 0; i <= maxIndex; i++) {
		double key = theKeys.get(i);
	    buf.append(String.valueOf(key));
		buf.append("->");
	    buf.append(String.valueOf(get(key)));
		if (i < maxIndex) buf.append(", ");
	}
	buf.append("]");
	return buf.toString();
}
 

/**
 * Returns a string representation of the receiver, containing
 * the String representation of each key-value pair, sorted ascending by value.
 */
public String toStringByValue() {
	DoubleArrayList theKeys = new DoubleArrayList();
	keysSortedByValue(theKeys);

	StringBuffer buf = new StringBuffer();
	buf.append("[");
	int maxIndex = theKeys.size() - 1;
	for (int i = 0; i <= maxIndex; i++) {
		double key = theKeys.get(i);
	    buf.append(String.valueOf(key));
		buf.append("->");
	    buf.append(String.valueOf(get(key)));
		if (i < maxIndex) buf.append(", ");
	}
	buf.append("]");
	return buf.toString();
}
 

/**
 * Computes the specified quantile elements over the values previously added.
 * @param phis the quantiles for which elements are to be computed. Each phi must be in the interval (0.0,1.0]. <tt>phis</tt> must be sorted ascending.
 * @return the approximate quantile elements.
 */
public DoubleArrayList quantileElements(DoubleArrayList phis) {
	if (precomputeEpsilon<=0.0) return super.quantileElements(phis);
	
	int quantilesToPrecompute = (int) Utils.epsilonCeiling(1.0 / precomputeEpsilon);
	/*
	if (phis.size() > quantilesToPrecompute) {
		// illegal use case!
		// we compute results, but loose explicit approximation guarantees.
		return super.quantileElements(phis);
	}
	*/
 
	//select that quantile from the precomputed set that corresponds to a position closest to phi.
	phis = phis.copy();
	double e = precomputeEpsilon;
	for (int index=phis.size(); --index >= 0;) {
		double phi = phis.get(index);
		int i = (int) Math.round( ((2.0*phi/e) - 1.0 ) / 2.0); // finds closest
		i = Math.min(quantilesToPrecompute-1, Math.max(0,i));
		double augmentedPhi = (e/2.0)*(1+2*i);
		phis.set(index,augmentedPhi);				
	}
	
	return super.quantileElements(phis);
}
 

/**
 * Returns a string representation of the receiver, containing
 * the String representation of each key-value pair, sorted ascending by key.
 */
public String toString() {
	DoubleArrayList theKeys = keys();
	theKeys.sort();

	StringBuffer buf = new StringBuffer();
	buf.append("[");
	int maxIndex = theKeys.size() - 1;
	for (int i = 0; i <= maxIndex; i++) {
		double key = theKeys.get(i);
	    buf.append(String.valueOf(key));
		buf.append("->");
	    buf.append(String.valueOf(get(key)));
		if (i < maxIndex) buf.append(", ");
	}
	buf.append("]");
	return buf.toString();
}
 

/**
 * Returns a string representation of the receiver, containing
 * the String representation of each key-value pair, sorted ascending by value.
 */
public String toStringByValue() {
	DoubleArrayList theKeys = new DoubleArrayList();
	keysSortedByValue(theKeys);

	StringBuffer buf = new StringBuffer();
	buf.append("[");
	int maxIndex = theKeys.size() - 1;
	for (int i = 0; i <= maxIndex; i++) {
		double key = theKeys.get(i);
	    buf.append(String.valueOf(key));
		buf.append("->");
	    buf.append(String.valueOf(get(key)));
		if (i < maxIndex) buf.append(", ");
	}
	buf.append("]");
	return buf.toString();
}
 

/**
 * Finds the first and last indexes of a specific element within a sorted list.
 * @return int[]
 * @param list cern.colt.list.DoubleArrayList
 * @param element the element to search for
 */
protected static IntArrayList binaryMultiSearch(DoubleArrayList list, double element) {
	int index = list.binarySearch(element);
	if (index<0) return null; //not found

	int from = index-1;
	while (from>=0 && list.get(from)==element) from--;
	from++;
	
	int to = index+1;
	while (to<list.size() && list.get(to)==element) to++;
	to--;
	
	return new IntArrayList(new int[] {from,to});
}
 

private static double covariance2(DoubleArrayList data1, DoubleArrayList data2) {
	int size = data1.size();
	double mean1 = Descriptive.mean(data1);
	double mean2 = Descriptive.mean(data2);
	double covariance = 0.0D;
	for (int i = 0; i < size; i++) {
		double x = data1.get(i);
		double y = data2.get(i);

		covariance += (x - mean1) * (y - mean2);
	}

	return covariance / (double) (size-1);
}
 

/**
 * Finds the first and last indexes of a specific element within a sorted list.
 * @return int[]
 * @param list cern.colt.list.DoubleArrayList
 * @param element the element to search for
 */
protected static IntArrayList binaryMultiSearch(DoubleArrayList list, double element) {
	int index = list.binarySearch(element);
	if (index<0) return null; //not found

	int from = index-1;
	while (from>=0 && list.get(from)==element) from--;
	from++;
	
	int to = index+1;
	while (to<list.size() && list.get(to)==element) to++;
	to--;
	
	return new IntArrayList(new int[] {from,to});
}
 

private static double covariance2(DoubleArrayList data1, DoubleArrayList data2) {
	int size = data1.size();
	double mean1 = Descriptive.mean(data1);
	double mean2 = Descriptive.mean(data2);
	double covariance = 0.0D;
	for (int i = 0; i < size; i++) {
		double x = data1.get(i);
		double y = data2.get(i);

		covariance += (x - mean1) * (y - mean2);
	}

	return covariance / (double) (size-1);
}