Aggregate data to weekly level with every week starting from Monday

Question

I have a data frame like,

2015-01-30     1       Fri
2015-01-30     2       Sat
2015-02-01     3       Sun
2015-02-02     1       Mon
2015-02-03     1                


        

Answer 1

Wit dplyr and lubridate is this really easy thanks to the function isoweek

my.df <- read.table(header=FALSE, text=
  '2015-01-30     1       Fri
   2015-01-30     2       Sat
   2015-02-01     3       Sun
   2015-02-02     1       Mon
   2015-02-03     1       Tue
   2015-02-04     1       Wed 
   2015-02-05     1       Thu
   2015-02-06     1       Fri
   2015-02-07     1       Sat
   2015-02-08     1       Sun')
 my.df %>% mutate(week = isoweek(V1)) %>% group_by(week) %>% summarise(sum(V2))

or a bit shorter

my.df %>% group_by(isoweek(V1)) %>% summarise(sum(V2))