warning: [unchecked] unchecked cast  DOUBLE & NUMBER

import java.math.BigDecimal;
 
public class MathArray<N extends Number> {
 
	private N[] array; 
 
	MathArray(N[] array) {
		this.array = array;
	}
 
 
	void warnNaN( Double bd ) { 
		if(( bd.isNaN() ) )
			System.err.println("Warning: result is undefined"); 
	} 
 
	void warnNaN( Number bd ) {
		warnNaN( new Double( bd.doubleValue() ) ) ;
	}
 
	void applyNeg() { 
		for(int i = 0; i < array.length; i++) { 
			array[i] = ( N )negate( array[i] ); 
			warnNaN(array[i]); 
		} 
	} 
 
	private Number negate( BigDecimal bd ){
		return bd.negate() ;
	}
 
	private Number negate( Double bd ){
		return bd.isNaN() ? bd : new BigDecimal( bd.doubleValue() ).negate() ;
	}
 
	private Number negate( Number bd ){
		return negate( new Double( bd.doubleValue() ) ) ; //OVERLOAD THE ABOVE METHOD TO OTHER TYPES
	}
 
 
	void applySqrt() { 
		for(int i = 0; i < array.length; i++) { 
			array[i] = ( N )new Double( Math.sqrt(array[i].doubleValue() ) ); 
			warnNaN(array[i]); 
		} 
	} 
 
	void applySin() { 
		for(int i = 0; i < array.length; i++) { 
			array[i] = ( N )new Double( Math.sin(array[i].doubleValue()) ); 
			warnNaN(array[i]); 
		} 
	} 
 
	void applyCos() { 
 
		for(int i = 0; i < array.length; i++) { 
 
			array[i] = ( N )new Double( Math.cos(array[i].doubleValue() ) ); 
 
			warnNaN(array[i]); 
 
		} 
 
	} 
 
	void print() { 
 
		for(int i = 0; i < array.length; i++) 
			System.out.print(array[i] + (i < array.length-1?", ":"\n")); 
 
	} 
 
	public static void main(String[] args) { 
 
		MathArray<Number> te = new MathArray<Number>( new Number[]{ new BigDecimal( 0.1 ), new BigDecimal( 2.23 ), new BigDecimal( 3.08 ) } ); 
 
		// apply -Sqrt(Sin(x)) to each element x in the array: 
 
		te.applySin(); 
 
		te.applySqrt(); 
 
		te.applyNeg(); 
 
		te.print(); 
 
	} 
}