finding the average from an arraylist

[sumprit]

Hi everyone! i am trying to find the average from an arraylist conatining database values. My database table have 9 columns and has 168 rows. Now i need to find the average at an interval of 12.

My database table has time as 1 column and 8 other columns with parameters like temperature,rainfall and so on.... Now i need to calculate the average of the values at an interval of 12 hours. i query the result and store in a resultset and then i iterated it, but i have no idea of proceeding further after that. please give some suggestion or hints so that i can able to find the result.

please show me the way. Thanks in advance.

[ztini]

Kind of depends on how "time" is stored in your db.

But basically, you want to start a loop at time zero and continue until you hit 12 hours. Along the way you want to do 2 things. One, count the number of ResultSet rows and two, extract the temp using ResultSet.getDouble("Temp") and store each row temp as a culmulative sum. This assumes that column "Temp" is stored in your database as a double. I suspect its probably a string, so you'll need:

ResultSet rs;
String temp = rs.getString("Temp");
double tempAsDouble = Double.parseDouble(temp);

At the end of the loop, just do (sumOfTemps / countOfRows) to get your average.

Loop again if ResultSet is not empty.

[sumprit]

Thank you for your guidance. But will you please explain me in more details. Actually, i need to calculate the average of 7 days, but with an interval of 12 hours. i have database values for 7 days. so 7*24 means 168 rows and with 9 columns and i need to have average of 12 hour interval for 1 day i.e in 1 day 2 value will come so i must have 2*7 means 14 values(avg values).

Please guide me. I am completely confused. i cannot able to proceed further. Please take me to the right track.