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Thread: Reading file of floats into array list and sorting into subsets

  1. #1
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    Default Reading file of floats into array list and sorting into subsets

    Hello, I am working on an assignment where I need to sort floats into subsets based on deviation. I need to pull the first element out and use it to compare the rest. a good way to think about it is d = first element and a = the first element in the remaining list, and b = the second element in the list. I need to put the floating points into subset where the elements are at least d apart

    Example: d= 2 and list {5, 7, 8, 12, 4, 6, 7}
    needs to be put into sets {5, 7, 12} {8, 4, 6} {7}

    this is what I have so far

    import java.io.File;
    import java.io.FileNotFoundException;
    import java.util.ArrayList;
    import java.util.Scanner;
    import java.util.Collections;
     
    public class FloatFromFile
    {
    	public static void main(String[] args)
    	{
    		Scanner file = null;
    		ArrayList<Float> list = new ArrayList<Float>();
     
    		try
    		{
    			file = new Scanner(new File("test.txt"));
    		}
    		catch (FileNotFoundException e)
    		{
    			e.printStackTrace();
    		}
     
    		while(file.hasNext())
    		{
    			if (file.hasNextFloat()) list.add(file.nextFloat());
    			else file.next();
    		}
     
    		// display unsorted list
    		System.err.print("Origional List is:\n");
    		for (Float i: list) System.out.println(i);
     
    		Collections.sort(list);
     
    		// display sorted list
    		System.err.print("Sorted List is:\n");
    		for (Float i: list) System.out.println(i);
     
    		ArrayList<Float> sorted = new ArrayList<Float>();
    		while (file.hasNext())
    		{
    			Float val = file.nextFloat();
    			int i = sorted.size();
    			float temp = sorted.get(i-1);
    			while (i > 0 && temp > val)
    			{
    				i--;
    				temp = sorted.get(i-1);
    			}
    			sorted.insert(i, val);
    		}
    		for (Float i: sorted) System.out.println(i);
     
     
    		}
    }

    I am getting one error with the sorted.insert(i, val), but I know that is not the only problem. Any help would be great.


  2. #2
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    Default Re: Reading file of floats into array list and sorting into subsets

    We don't read minds. Do you think that posting the exact error message might be helpful?
    Improving the world one idiot at a time!

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    Default Re: Reading file of floats into array list and sorting into subsets

    Quote Originally Posted by Junky View Post
    We don't read minds.
    Speak for yourself... at the moment, I'm sensing that you're tired and grumpy!
    And believe me, that was no party trick, It's just something you pick up from a year of JavaPenguin
    Please use [highlight=Java]//code goes here...[/highlight] tags when posting your code

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