date - Aggregate daily level data to weekly level in R

Question

I have a huge dataset similar to the following reproducible sample data.

   Interval    value
1  2012-06-10   552
2  2012-06-11  4850
3  2012-06-12  4642
4  2012-06-13  4132
5  2012-06-14  4190
6  2012-06-15  4186
7  2012-06-16  1139
8  2012-06-17   490
9  2012-06-18  5156
10 2012-06-19  4430
11 2012-06-20  4447
12 2012-06-21  4256
13 2012-06-22  3856
14 2012-06-23  1163
15 2012-06-24   564
16 2012-06-25  4866
17 2012-06-26  4421
18 2012-06-27  4206
19 2012-06-28  4272
20 2012-06-29  3993
21 2012-06-30  1211
22 2012-07-01   698
23 2012-07-02  5770
24 2012-07-03  5103
25 2012-07-04   775
26 2012-07-05  5140
27 2012-07-06  4868
28 2012-07-07  1225
29 2012-07-08   671
30 2012-07-09  5726
31 2012-07-10  5176

I want to aggregate this data to weekly level to get the output similar to the following:

   Interval           value
1  Week 2, June 2012  *aggregate value for day 10 to day 14 of June 2012*
2  Week 3, June 2012  *aggregate value for day 15 to day 21 of June 2012*
3  Week 4, June 2012  *aggregate value for day 22 to day 28 of June 2012*
4  Week 5, June 2012  *aggregate value for day 29 to day 30 of June 2012*
5  Week 1, July 2012  *aggregate value for day 1 to day 7 of July 2012*
6  Week 2, July 2012  *aggregate value for day 8 to day 10 of July 2012*

How do I achieve this easily without writing a long code?

Answer 1

If you mean the sum of of ‘value’ by week I think the easiest way to do it is to convert the data into a xts object as GSee suggested:

data <- as.xts(data$value,order.by=as.Date(data$interval))
weekly <- apply.weekly(data,sum)

            [,1]
2012-06-10   552
2012-06-17 23629
2012-06-24 23872
2012-07-01 23667
2012-07-08 23552
2012-07-10 10902

I leave the formatting of the output as an exercise for you :-)