/** PolynomialD1.java defines a degree 1 polynomial class.
 *  Author:  Joel C. Adams
 *  Version: For Java: An Introduction to Computing 1/e.  All Rights Reserved.
 *  NOTE: Polynomial terms are white-space delimited.
 *  Examples: 1 + 2x, 1 +2x, 1 -2x are all ok.
 */

package ann.math.polynomial;

import ann.util.Controller;
import java.util.StringTokenizer;

public class PolynomialD1 extends PolynomialD0
{
 /** Default constructor
  *  Postcondition: myB == 0.0 && myA == 0.0.
  */
 public PolynomialD1()
 {
   super();
   myB = 0.0;
 }
 /** Construct from double
  *  Receive:       double aValue, double bValue.
  *  Postcondition: myA == aValue && myB == bValue.
  */
 public PolynomialD1(double aValue, double bValue)
 {
   super(aValue);
   myB = bValue;
 }

 /** Construct from String
  *  Receive:       String polyString.
  *  Precondition:  strPolyD1 is of the form "a + bx" or "a + bX",
  *                  where a and b are numeric values.
  *  Postcondition: myA == a && myB == b.
  */
 public PolynomialD1(String polyString)
 {
   super(polyString);              // process A term (using myTokenizer)
   myB = getNextCoefficient();     // process B term (same way)
 }
 
 /* B-attribute accessor
  * Return: myB.
  */
 public double getB()
 {
   return myB;
 }

 /** B-attribute mutator
  *  Receive:       double newB.
  *  Postcondition: myB == newB.
  */
 public void setB(double newB)
 {
   myB = newB;
 }

 /** String converter (output)
  *  Return: the String equivalent to myA.
  */
 public String toString()
 {
   if (myB < 0)
     return super.toString() + " - " + Double.toString(-myB) + "x";
   else
     return super.toString() + " + " + Double.toString(myB) + "x";
 }

 //--- Attribute variable ---
 private double myB;
}