CODEWITHSUNDEEP
rdate
shiny
shiny

Reputation: 3502

Extract the day of fortnight from Date objects?

In my analysis, I have to extract the day of a week and the day number of each fortnight from Date objects. I want the result to look like below

Date                 weekday         fortnightly    
2010-05-01           Saturday            1 
2010-05-02           Sunday              2
.
.
2010-05-14           Friday              14 
2010-05-15           Saturday            1
2010-05-16           Sunday              2
.
.
2010-05-28           Friday              14  
2010-05-29           Saturday            1
2010-05-30           Sunday              2
2010-05-31           Monday              3  
2010-06-1            Tuesday             4
2010-06-2            Wednesday           5

I extracted the weekday as below

df$weekday <- weekdays(as.Date(df$Date))

However, I don't know which function I can use to extract the day number for each fortnight.

Any suggestions would be appreciated.

Upvotes: 1

Views: 379

Answers (2)

akrun
akrun

Reputation: 887891

We can try

(seq_along(v1)-1)%%14 + 1L
#[1]  1  2  3  4  5  6  7  8  9 10 11 12 13 14  1  2  3  4  5  6  7  8  9 10 11
#[26] 12 13 14  1  2  3  4  5  6  7  8  9 10 11 12 13 14  1  2  3  4  5  6  7  8
#[51]  9 10 11 12 13 14  1  2  3  4

data

v1 <- seq(as.Date('2010-05-01'), length.out=60, by = '1 day')

Upvotes: 2

Ronak Shah
Ronak Shah

Reputation: 389275

Is this what you want?

Taking @akrun's data as reference

v1 <- seq(as.Date('2010-05-01'), length.out=60, by = '1 day')
c(rep(seq(1, 14, 1), floor(length(v1)/14)), 1:(length(v1)%%14))

# [1]  1  2  3  4  5  6  7  8  9 10 11 12 13 14  1  2  3  4  5  6  7  8  9 10 11 12 13 14  1  2  3  4
# [33]  5  6  7  8  9 10 11 12 13 14  1  2  3  4  5  6  7  8  9 10 11 12 13 14  1  2  3  4

Repeating a sequence of numbers from 1 to 14 for length(v1)/14 times and then appending the remaining numbers.

So if in your case it's a data frame then you can try, 

c(rep(seq(1, 14, 1), floor(nrow(df)/14)), 1:(nrow(df)%%14))

which would again generate the same sequence.

Upvotes: 2

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