[R] interpolation to montly data

[stef salvez]

I have a panel data set (in MS excel)  like the one below


 1         "23/11/08"            2
1   "28/12/08"                   3
1    "25/01/09"                   4
1   "22/02/09"                   5
1    "29/03/09"                  6
1  "26/04/09"                   32
1  "24/05/09"                   23
1  "28/06/09"                   32
2   "26/10/08"                45
2  "23/11/08"                 46
2  "21/12/08"               90
2  "18/01/09"                54
2  "15/02/09"                 65
2   "16/03/09"               77
2  "12/04/09"                    7
2   "10/05/09"                   6




the start and end date of the time series for countries 1 and 2 are
different. For example, for country 1 the time series begins on
"23/11/08" while for country 2 the time series begins on "26-10-2008”.

My data on prices are available every 28 days (or equivalently every 4
weeks). But in some cases I have jumps (35 days or 29 days instead of
28 days). For example from the above table we have such jumps: from
"28/12/08" to "28/12/08" , from 22/02/09" to "29/03/09", etc

My goal is to have a unified sequence of dates across countries. So,
to achieve this I want to apply the following solutions

I want  to take what I have and calculate monthly average prices and also
report how many prices those averages are based on. I suppose that I
will still have gaps and may well need to interpolate.

Please, I would be grateful to you if you could provide the exact code
for doing this


thanks a lot