create an unique week variable NOT depending on the calendar in R - r

Question

I have a daily revenue time series df from 01-01-2014 to 15-06-2017 and I want to aggregate the daily revenue data to weekly revenue data and do the weekly predictions. Before I aggregate the revenue, I need to create a continuously week variable, which will NOT start from week 1 again when a new year starts. Since 01-01-2014 was not Monday, so I decided to start my first week from 06-01-2014.
My df now looks like this
date year month total
7 2014-01-06 2014 1 1857679.4
8 2014-01-07 2014 1 1735488.0
9 2014-01-08 2014 1 1477269.9
10 2014-01-09 2014 1 1329882.9
11 2014-01-10 2014 1 1195215.7
...
709 2017-06-14 2017 6 1677476.9
710 2017-06-15 2017 6 1533083.4
I want to create a unique week variable starting from 2014-01-06 until the last row of my dataset (1257 rows in total), which is 2017-06-15.
I wrote a loop:
week = c()
for (i in 1:179) {
week = rep(i,7)
print(week)
}
However, the result of this loop is not saved for each iteration. When I type week, it just shows 179,179,179,179,179,179,179
Where is the problem and how can I add 180, 180, 180, 180 after the repeat loop?
And if I will add more new data after 2017-06-15, how can I create the weekly variable automatically depending on my end of row (date)? (In other words, by doing that, I don't need to calculate how many daily observations I have and divide it by 7 and plus the rest of the dates to become the week index)
Thank you!

Answer 1

Does this work
library(lubridate)
#DATA
x = data.frame(date = seq.Date(from = ymd("2014-01-06"),
to = ymd("2017-06-15"), length.out = 15))
#Add year and week for each date
x$week = year(x$date) + week(x$date)/100
#Convert the addition of year and week to factor and then to numeric
x$week_variable = as.numeric(as.factor(x$week))
#Another alternative
x$week_variable2 = floor(as.numeric(x$date - min(x$date))/7) + 1
x
# date week week_variable week_variable2
#1 2014-01-06 2014.01 1 1
#2 2014-04-05 2014.14 2 13
#3 2014-07-04 2014.27 3 26
#4 2014-10-02 2014.40 4 39
#5 2014-12-30 2014.52 5 52
#6 2015-03-30 2015.13 6 65
#7 2015-06-28 2015.26 7 77
#8 2015-09-26 2015.39 8 90
#9 2015-12-24 2015.52 9 103
#10 2016-03-23 2016.12 10 116
#11 2016-06-21 2016.25 11 129
#12 2016-09-18 2016.38 12 141
#13 2016-12-17 2016.51 13 154
#14 2017-03-17 2017.11 14 167
#15 2017-06-15 2017.24 15 180

Answer 2

Here is the answer:
week = c()
for (i in 1:184) {
for (j in 1:7) {
week[j+(i-1)*7] = i
}
}
week = as.data.frame(week)
I created a week variable, and from week 1 to the week 184 (end of my dataset). For each week number, I repeat 7 times because there are 7 days in a week. Later I assigned the week variable to my data frame.