How to group a list of data into year, season, month, week, day?

Question

I am dealing with big data of years.

The data model is quite simple:

public class ValueData
{
    public DateTime TimeRecorded {get; set;}
    public double   ValueRecorded {get; set;}
}

After having a list of ValueData: List<ValueData> for years of data, I need to group the data based on: Year ==> contains data of 4 seasons: Season ==> A season contains 4 months ==> A month contains data of 4 weeks ==> A week contains data of 7 days based on the week calendar numbers of a year. Because I need to make a sum of data per year, per season, per month, per week and per day

How can I achieve this data classification? should I use LinQ?

You can use LINQ and you can use a different approach. However, where did you get stuck? This sounds like a requirement specification. — Tim Schmelter, Apr 07 '14 at 14:53
@TimSchmelter im stucking to find a way to group data based on year, season, month, week and day. Which is another approach that you can think of? — olidev, Apr 07 '14 at 15:01
Are you after something like `var grp = dataList.GroupBy(d => new { Year=d.TimeRecorded.Year, Month=d.TimeRecorded.Month, }).ToList();` ? — huMpty duMpty, Apr 07 '14 at 15:22

score 0 · Answer 1 · edited May 23 '17 at 12:20

0

I guess you are looking for something like conditional groups but 2gbs of data will take a while to process. I guess it's ok for a one time parse and save the results but if you need to run this often you'll need a more appropriate solution.

edited May 23 '17 at 12:20

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answered Apr 07 '14 at 15:14

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score 0 · Answer 2 · answered Apr 07 '14 at 18:30

I believe you want something along the lines of the following query:

var groups = data.GroupBy(v => new {Year = v.TimeRecorded.Year,
                                    Season = SeasonFromMonth(v.TimeRecorded.Month),
                                    Month = v.TimeRecorded.Month,
                                    Week = System.Globalization.CultureInfo.InvariantCulture.Calendar.GetWeekOfYear(v.TimeRecorded, System.Globalization.CalendarWeekRule.FirstDay, System.DayOfWeek.Monday),
                                    Day = v.TimeRecorded.Day});

With a helper function SeasonFromMonth that accepts the integer month and returns some value (probably an enum) indicating the season.

You can then select relevant subgroups with queries like:

var fallValues = groups.Where(g => g.Key.Season == Seasons.Fall);
var decemberValues = groups.Where(g => g.Key.Month == 12);
var firstOfMonth = groups.Where(g => g.Key.Day == 1);

and so on, or flatten the groups into a single list by adding a SelectMany clause (although the SelectMany will throw away the key information):

groups.Where(g => g.Key.Season == Seasons.Fall).SelectMany(g => g);
groups.Where(g => g.Key.Month == 12).SelectMany(g => g);
groups.Where(g => g.Key.Day == 1).SelectMany(g => g);

How to group a list of data into year, season, month, week, day?

2 Answers2