How to Convert a List to List

Question

_{Friday, July 17, 2015 3:23 PM}

Hi all,

I have a time-series Data, stored in my DataBase in the Format

Date           Price

03-Jan-86   15.6
10-Jan-86   63.2
17-Jan-86   56.9
24-Jan-86
31-Jan-86
07-Feb-86
 

and i want to to store them in a List<DateTime> and then Convert this list to  List<double> in order to place them in a numeric variable for some R.NET statistical calculations

I have load them in the List<DateTime> (the first column) but now how can i convert em to double list?

All replies (6)

_{Sunday, July 19, 2015 11:49 AM ✅Answered | 1 vote}

Hi thanks for your response. I dont have clear answer but guessing because i never done it before.

I have checked how R studio imports the Data and from this format 03-Jan-86 it imports data into a DataFrame

at this format  Jan 03, 1986.

I am close to find the solution but i have been stacked at this point for a days

Hello,

DateTime.ToOADate() method will return a double Ole Automation date. I think this is what you want.

If you want to convert the datetime to a custom format like "Jan 03, 1986", you can use the format string like this:

DateTime date=Convert.ToDateTime("03-Jan-86");
string customDate = date.ToString("MMM dd, yyyy");

If it's not correct, I think you need to post your question in the R.NET codeplex site, as the owner of this opensource library for how to get the right date format:

http://rdotnet.codeplex.com/

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_{Friday, July 17, 2015 3:33 PM}

List<DateTime> dates; //assuming you loaded the values to this list

List<long> longDates = new List<long>();

foreach(var d in dates)
{
  longDate.Add(d.Ticks);
}

or

List<long> longDate = new List<long>();

longDate.AddRange(dates.Select(d => d.Ticks));

sivanitha

_{Friday, July 17, 2015 3:50 PM}

Hi Sivathina before i mark it as answered i would like to make a clarification

Why did you save it in a long and not in a double?

and the second one if i try to check the type it returns me MessageBox.Show(longDates.GetType().ToString());

Generic List [System.int64]. Can i use it as numeric as well?

Thanks a lot

I think i almost done

Aris

_{Friday, July 17, 2015 3:58 PM}

DateTime.Ticks returns a long value - the number of 100-nanosecond intervals since midnight January 1st, 0001.

How exactly do you expect a date and time to be represented as a numeric value?

_{Friday, July 17, 2015 4:23 PM}

Hi thanks for your response. I dont have clear answer but guessing because i never done it before.

I have checked how R studio imports the Data and from this format 03-Jan-86 it imports data into a DataFrame

at this format  Jan 03, 1986.

I am close to find the solution but i have been stacked at this point for a days

_{Sunday, July 19, 2015 11:21 PM}

YES! this is the correct answer! So i will give a better description in case some in the future has the same problem.

I am loading all my Date Column from MySql in this list

List<DateTime> listA = new List<DateTime>(); and i convert this list to double in order to use it as numeric vecror in R.NET

List<double> listAtoDouble = new List<double>();

foreach (var d in listA)
                {
                    listAtoDouble.Add(d.ToOADate());
                    
                }

**** NOTE

The only problem now is that they dont appear in an appropriate format. Dates apperar like 32000 34000 36000