public class RandomR {
  private double d;  //distance between joints
  private int joints; //number of joints
  private double[] load; //array for loads

  private int default_d = 10;  //default value for distance between joints
  private int default_joints = 5;  //default value for number of joints

  private double min_load = 20;  //min value of load created
  private double range = 100.0;  //range for load i.e. loads created from min_load to 80
  private double chance = 0.5;  //probability that load is created
  
  public RandomR() {  //default constructor
    this.d = default_d;
    this.joints = default_joints;
    this.load = new double[joints+1];
    computeLoads();
  }

  public RandomR(int d) {
    this();  //calls default constructor
    this.d = d;
  }
  
  public RandomR(int d, int joints) {
    this(d);  //calls RandomR(int d) constructor
    this.joints = joints;
    this.load = new double[joints+1];
  }
   
  public double[] getLoads() {
    return load;
  }

  public void computeLoads() {
    boolean none = true;  //makes sure at least one load created
    for (int i=1; i<=joints; i++) {
      if (Math.random() < chance) {
        load[i] = Math.random()*range;  //generates random numbers from 0 to Range
        if (load[i]<min_load) load[i] = min_load;  //makes sure load greater than min_value
        none = false;
      }
      else {
        load[i] = 0;  //generate zero load
      }
    }
    if (none == true) {
      int randomPosition;
      randomPosition = (int)(Math.random()*joints);
      if (randomPosition == 0) randomPosition = 1;
      load[randomPosition] = min_load;  //assigns min_load to random joint if no loads created
    }
  }

  public double getReactionA() {
    double RA = 0;
    double RATemp = 0;
    for (int i=1; i<=joints; i++) {
      RATemp = RATemp + load[i]*(joints-i+1)*d;
    }
    RA = RATemp/((joints+1)*d);
    return RA;
  }
  
  public double getReactionB() {
    double RB = 0;
    double RBTemp = 0;
    for (int i=1; i<=joints; i++) {
      RBTemp = RBTemp + load[i]*(i)*d;
    }
    RB = RBTemp/((joints+1)*d);
    return RB;
  }  
  
  public double getD() {
    return this.d;
  }

  public double getJoints() {
    return this.joints;
  }

}