average

I was wondering if it's possible to calculate the average of some numbers if I have this: int currentCount = 12; float currentScore = 6.1123 (this is a range of 1 <-> 10). Now, if I receive another score (let's say 4.5), can I recalculate the average so it would be something like: int currentCount now equals 13 float currentScore now equals ????? or is this impossible and I still need to remember the list of scores? The following formulas allow you to track averages just from stored average and count, as you requested. currentScore = (currentScore * currentCount + newValue) / (currentCount + 1

.NET Framework 3.5. I'm trying to calculate the average of some pretty large numbers. For instance: using System; using System.Linq; class Program { static void Main(string[] args) { var items = new long[] { long.MaxValue - 100, long.MaxValue - 200, long.MaxValue - 300 }; try { var avg = items.Average(); Console.WriteLine(avg); } catch (OverflowException ex) { Console.WriteLine("can't calculate that!"); } Console.ReadLine(); } } Obviously, the mathematical result is 9223372036854775607 ( long.MaxValue - 200 ), but I get an exception there. This is because the implementation (on my machine) to

Ok experts...I've got a table that I am trying to calculate the average of the values in a column. Here is my lookup: $gameswon = mysql_query("SELECT SUM(P1_Score) AS value_sum FROM tblMatches Where P1_ID LIKE '".$playerid."'"); Any idea how I can determine the average (sum of values / total rows)? Thanks for your help. Obviously it is SELECT AVG(P1_Score) So in your case: $gameswon = mysql_query("SELECT AVG(P1_Score) AS value_sum FROM tblMatches WHERE P1_ID LIKE '".$playerid."'"); Try using AVG() aggregate function instead of SUM $gameswon = mysql_query("SELECT AVG(P1_Score) AS value_sum FROM

Is there a built-in method to calculate the average of an integer ArrayList? If not, can I make a function that will do that by taking in the name of the ArrayList and returning its average value? Óscar López It's really simple: // Better use a `List`. It is more generic and it also receives an `ArrayList`. public static double average(List<Integer> list) { // 'average' is undefined if there are no elements in the list. if (list == null || list.isEmpty()) return 0.0; // Calculate the summation of the elements in the list long sum = 0; int n = list.size(); // Iterating manually is faster than

Is there an easy way to obtain the average of an attribute in a collection? For instance, each user has a score. Given a collection of user(s) (@users), how can you get the average score for the group? Is there anything like @users.average(:score)? I think I came across something like this for database fields, but I need it to work for a collection... For your question, one could actually do: @users.collect(&:score).sum.to_f/@users.length if @users.length > 0 Earlier I thought, @users.collect(&:score).average would have worked. For database fields, User.average(:score) will work. You can also