Solved Getting 5 nearest entities?

I know there is the getNearbyEntities method but I don't want all the nearest entities I just want to select 5 random ones. Anyone know how to go about doing this? All help is appreciated

 

marshmallowz
getNearbyEntities returns list of entity. Just choose five values at random indexes.

 

Gater12
I can't wrap my head around how to do this, if it won't be much trouble can you show me an example?

 

This is gonna help:

http://docs.oracle.com/javase/7/docs/api/java/util/Collections.html#shuffle(java.util.List)

Call Collections.shuffle on the result of getNearbyEntities, and then just use the first 5 entries from the resulting list.

 

NathanWolf
I've never used that method before, can you help me?

 

Code:java

 
List<Entity> ents = new ArrayList<Entity>();
for (int i = 0; i < 5; i++) {
    Entity nearest = null;
    for (Entity ent : player.getNearbyEntities()) {
        if (nearest != null) {
            if (ent.getLocation().distance(player.getLocation() < nearest.getLocation().distance(player.getLocation)) {
                nearest = ent;
            }
        } else {
            nearest = ent;
        }
    }
    ents.add(nearest);
}
 

 

thecrystalflame
The getNearbyEntities takes 3 parameters of the x,y,z for the range

 

I pretty much spelled it out there.... I don't like to spoonfeed, but I guess here:

Code:

Collection<Entity> nearby = player.getNearbyEntities(16, 16, 16);
Collections.shuffle(nearby);
 
Entity randomEntity1 = nearby.get(0);
Entity randomEntity2 = nearby.get(1);
Entity randomEntity3 = nearby.get(2);
Entity randomEntity4 = nearby.get(3);
Entity randomEntity5 = nearby.get(4);

 

thecrystalflame

Spoonfeeding is detrimental to learning, especially without any kind of explanation, and even moreso when you're spoonfeeding unnecessarily inefficient and hard-to-grok code. There is absolutely no reason to call getNearbyEntities five times. Besides, your algorithm selects the five nearest, not five random, out of the set of nearby entities. Not only that, it also calls the inefficient distance method several times for what seems like no real reason.

For the purpose of selecting five entities at random in a list, shuffling and then popping the first (or last) five elements of the list is the cleanest way to do it (as suggested by NathanWolf), however generating five random indices would work equally well (and may be faster, depending on how big the list is in the average case, since random number generation is expensive, and the shuffle method runs in asymptotic linear time, whereas five random numbers is asymptotic constant time, both with random number generation as a constant factor).

NathanWolf
A minor detail to humans, but paramount to the compiler, is that the shuffle method takes a List, not a Collection, and the Collection interface has no get method :3

 

NathanWolf
Thanks for the help!