utils.ArrayOperations Maven / Gradle / Ivy

Go to download

Show more of this group Show more artifacts with this name
Show all versions of jstat Show documentation

Java Library for Statistical Analysis.

The newest version!

package utils;
import java.util.List;


public class ArrayOperations
{

	/**
	 * Returns an array of doubles
	 */
	public static double[] toArray(final List array){

		if(array == null){
			throw new NullPointerException("Input List is null");
		}

		double[] data = new double[array.size()];

		for (int i = 0; i < array.size(); i++) {
			data[i] = array.get(i);
		}

		return data;

	}

	/**
	  * Returns the sum of the array elements
	  */
	public static  Double sum(List< Double > array){

		if(array == null){
			throw new NullPointerException("Input List is null");
		}

		double result = 0.0;

		for(Double element : array){
			result += element;
		}

		return result;
	}


	/**
	  * Returns the squared sum of the arraty elements
	  */
	public static  Double sumSqr(List< Double > array ){

		if(array == null){
			throw new NullPointerException("Input List is null");
		}

		double result = 0.0;

		for(Double element : array){

            result += ( element*element );
		}

		return result;
	}


    /**
      * Returns the maximum element in the List
     */
	public static Double max(List< Double > array){

		if(array == null){
			throw new NullPointerException("Input List is null");
		}

		Double result = array.get(0);
		
		for(Double element : array){
			
			if(element > result){
                result = element;
			}	
		}
		
		return result;
	}


    /**
     * Returns the minimum element in the array
     */
	public static Double min(List< Double > array ){

		if(array == null){
			throw new NullPointerException("Input List is null");
		}

		Double result = array.get(0);
		
		for(Double element : array){
			
			if(element < result){
                result = element;
			}	
		}
		
		return result;
	}
	
}