How to calculate difference between dates while values in rows are equal?

Hi all, I want to find rows where the values in the first column of the matrix are equal (identifying number for stocks) and calculate the difference between the the start date of equal values and the last date of equal values. Then I want to check if the difference between dates are < 20 and if so, I want to delete the part of the matrix between the dates. In the file attached, the first column if the identifying number of the stocks, and the second column are the dates in serial date numbers. Hope anyone can help!

Many thanks in advance!

Answer 1

[vijaya lakshmi]

Hi Louisa,

In order to find the difference between 2 dates which are stored in 'serial date number' format

First, convert the "serial date number" format to "date" format

   t1=datetime(725617,'ConvertFrom','datenum');
      t2=datetime(725618,'ConvertFrom','datenum');

Later find the difference between dates

 diff= datenum(t2) - datenum(t1);

Or the other way is, directly find the difference between the dates which are in "serial date number" format

datenum(725620)-datenum(725619)