How can I index the dates of double data type ?

I have a column in a table that contains dates from 1-Jan-2013 to 15-Sep-2018 in the following format : 20130101, 20130102,...,20180915. I want assign index to the dates i.e. index=1 to 20130101, index=2 to 20130102 and so on. The dates are in double datatype and not datetime datatype. Can someone tell me how to do this?

Answer 1

[Walter Roberson]

Take the third output of unique() as the indices and the first output as the list of what the indices refers to.

You can also look at categorical() but you need to know some implementation details to retrieve the indices.

Depending on what you want to do with the values, you should consider using datetime() on the values and converting the table into a timetable which you would then be able to index by datetime

[Peter Perkins]

Just for the record, numbers like that are super easy to convert:

>> datetime([20130101, 20130102, 20180915],'ConvertFrom','yyyymmdd')
ans = 
  1×3 datetime array
   01-Jan-2013 00:00:00   02-Jan-2013 00:00:00   15-Sep-2018 00:00:00

[Shivam Pande]

Got it. Thanks.