Hi. I'm new to Processing (as well as to programming in general). I'm teaching myself, and one of the first projects I'm attempting is a simple boid flocking program. I'm having difficulty with the section of code that determines the "cohesion" of the boids (the section highlighted in red below). The program compiles just fine without that section, but encounters this error when I add it in: "Cannot find anything named 'Boid1'."

I'm trying to copy the Pvector of one of the boids, so that I can then run some calculations based on that. The specific line of code is:

Boid1 Neighbour = Boid1s[Boid1] .get();

I know this is incorrect, as are many variants that I've tried. What is the correct syntax for this operation? Any suggestions?

If further clarification is needed, I'll gladly provide it.

Thanks!


// Creates an array of objects (with specified size)
Boid1[] Boid1s = new Boid1[5];

void setup() {
  size (600,400);
  smooth();
  // Initializing all the elements of the array
  for (int i = 0; i < Boid1s.length; i++) {
    Boid1s[i] = new Boid1();
  }
}

void draw() {
  background(255);
 
  for (int i = 0; i < Boid1s.length; i++) {
    Boid1s[i].run();
}
 
}


class Boid1 {  //defines the class

  PVector location;
  PVector velocity;
  PVector acceleration;
  float topspeed;
  float diameter;
  color c1;

  Boid1() {  //constructor function: gets called whenever a new boid is created
              //the below algorithms are referenced in the functions
    location = new PVector(random(width),random(height));
    velocity = new PVector(random(-2,2),random(-2,2));
    acceleration = new PVector(0,0);
    topspeed = 4;
    diameter = 15;
    c1 = color(random(100,255),random(0,70),random(0,70),200);
  }

 

void run(){  // the main function - calls all the other functions listed
 
  update();
  display();
  avoidEdges();
  cohesion();

 
}

// the below algorithms are called through the main function (see above)

  void update() {
   
    velocity.add(acceleration);
    velocity.limit(topspeed);
    location.add(velocity);

 
  }

  void display() {
    stroke(c1);
    fill(c1);
    ellipse(location.x,location.y,diameter,diameter);
  }

  void avoidEdges() {

    if ((location.x > width) || (location.x < 0)) {
      velocity.x = velocity.x*-1;;
    }
    if ((location.y > height) || (location.y < 0)){
      velocity.y = velocity.y*-1;
    }
   }
  
    void cohesion(){ // each agent steers towards the average position of its neighbours
 
    PVector aveLocation = new PVector(); // PVector to store average location
    int neighbourcount = 0; // int to count the number of neighbours
   
     for (int i = 0; i < Boid1s.length; i++){
      Boid1 Neighbour = Boid1s[Boid1] .get(); //Gets a copy of the vector, returns a PVector object.
      float distance = PVector.dist(location,Neighbour.location); //Calculates the Euclidean distance between                                     //points                                               
      if (distance < 100){
        aveLocation.add(Neighbour.location);
        neighbourcount++;
      }
    }
   
   
    aveLocation.div(neighbourcount); // divide by num neighbours to get the average - the center position of our near                                                                 //neighbours
    PVector toCenter = PVector.sub(aveLocation,Location); // make a vector to that point
    toCenter.normalize(); // scale it to 1
    toCenter.mult(.1); // multiply by .1
    acceleration.add(toCenter);    // add to the acceleration
   
  }
    

}  //closes class