Finding Multiple Modes In An Array

Question

I\'m trying to write a java method which finds all the modes in an array. I know there is a simple method to find the mode in an array but when there are more than one single mo

Answer 1

Hope this helps. This is my answer. Hope it helps

public List mode(double[] m) {
    HashMap freqs = new HashMap();
    for (double d : m) {
        Double freq = freqs.get(d);
        freqs.put(d, (freq == null ? 1 : freq + 1));
    }
    List mode = new ArrayList();
    List frequency = new ArrayList();
    List values = new ArrayList();

    for (Map.Entry entry : freqs.entrySet()) {
        frequency.add(entry.getValue());
        values.add(entry.getKey());
    }
    double max = Collections.max(frequency);

    for(int i=0; i< frequency.size();i++)
    {
        double val =frequency.get(i);
        if(max == val )
        {
            mode.add(values.get(i));
        }
    }
    return mode;
}