is there a jump of 2 months?

Dear all

I have the following sequence of dates

A={

 '24/09/2000'
    '22/10/2000'
    '19/11/2000'
    '17/12/2000'
    '14/01/2001'
    '11/02/2001'
    '11/03/2001'
    '08/04/2001'
    '03/06/2001'
    '01/07/2001'
    '29/07/2001'
    '26/08/2001'
    '23/09/2001'
    '21/10/2001'}

I want to see if I have a jump of two months. for instance, in the above example there is such a jump from '08/04/2001' to '03/06/2001'.

I am looking for an if statement

 if there is not such a jump 
    '...'
end

thanks

Answer 1

[José-Luis]

Assuming your data is ordered, and that you have the financial toolbox:

numDate = datenum(A,'dd/mm/yyyy');
numDate = numDate - numDate(1);
monthNumber = month(test) + 12 * year(test);
jumpMonth = [0; diff(monthNumber)];

The vector jumpMonth will contain the difference in months between two succesive dates.

Cheers!

Answer 2

[Wayne King]

The basic way to do it is using datenum()

 B = datenum(A,'dd/mm/yyyy'); 
 numdays = diff(B);
 nummonths = numdays/30;

Then you need to use floor(), round(),ceil() or something similar, but you will see that only one element of nummonths is close to 2 in value

So, in this example

 nummonths = ceil(nummonths);
 for nn = 1:length(nummonths)
 if (nummonths(nn) > 1.5 & nummonths(nn) < 3.5)
   disp('There''s a jump');
 else
    disp('No Jump');
 end
 end

Anyway, you get the point.

Answer 3

[Andrei Bobrov]

[m,m] = datevec(A,'dd/mm/yyyy');
test = [0;mod(diff(m),12)] == 2;