Calculating the Mode

[Nemeliza]

I need to calculate the mode of 50 numbers and im struggling on how to go abouts doing this. Mathematically i have no problem but writing a program to do this is another matter.
This is what im thinking:

first of all, is there a java function that can do this????

• store the given numbers in an array
• sort the array
• compare a value in the array to the next value in the array (incrementing array[value1] and array[value2] accordingly)
• where value1 == value2 increment x (incrementing array[value1] and array[value2] accordingly)
• until end of array
• print (x+1)

I know this pseudo is very vague but i hope its enough to get my point accross.

Thanks,
nem.

[DaBeeeenster]

You could use a HashMap. Store the number in the array as the index of the HashMap entry, and then increment it every time it is found in the array. So

HashMap numbers = new HashMap();

for (i=0; i < array.size; i++) {
Integer thisNumber = numbers.get(array[i]);
if (thisNumber == null) {
numbers.put(new Integer(array[i], new Integer(1));
} else {
thisNumber = new Integer(thisNumber.intValue() + 1);
}
}

Then just enumerate through the hashmap looking for the entry with the largest value.

API for the HashMap:
http://java.sun.com/j2se/1.3/docs/ap...l/HashMap.html

Sorry - it's a bit rushed as I have to go out. Let me know if you need more help.

[directhex]

i use mode calculation in my 3rd year project, which is ansi c

convert the following idea to a more friendly javatastic form: a tally chart

page through all the values. if the value has been encountered before increment its value in a tally chart, else add it to the bottom of the chart. then parse the chart with an ultra-simple if(entry[n+1]>entry[n]) largest=entry[n+1];