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0

I have a list of every day from 2018-01-01 to 2018-06-01. It is a vector and it looks like this:

dates <- c("2018-01-01", "2018-01-02", "2018-01-03", ... , "2018-05-30", "2018-06-01")

I want to make a data frame where the first column has each of those dates and the second column has their day of the week. I am assuming that 2018-01-01 is a Monday.

date day
2018-01-01 Monday
2018-01-02 Tuesday
2018-01-03 Wednesday
... ...
2018-06-01 Monday

I'm working on a data frame towards that end, but I was curious for a better way to recycle through the days of the week than the solution I put together.

day <- NULL
for (i in 1:length(dates)) 
 x <- i
 while (x > 7) 
 x <- i - 7
 
 day <- c(day, days[x])


cbind(dates,day)

r

share|improve this question

asked Mar 26 at 2:20

CauderCauder

1741111 bronze badges

add a comment | 

0

I have a list of every day from 2018-01-01 to 2018-06-01. It is a vector and it looks like this:

dates <- c("2018-01-01", "2018-01-02", "2018-01-03", ... , "2018-05-30", "2018-06-01")

I want to make a data frame where the first column has each of those dates and the second column has their day of the week. I am assuming that 2018-01-01 is a Monday.

date day
2018-01-01 Monday
2018-01-02 Tuesday
2018-01-03 Wednesday
... ...
2018-06-01 Monday

I'm working on a data frame towards that end, but I was curious for a better way to recycle through the days of the week than the solution I put together.

day <- NULL
for (i in 1:length(dates)) 
 x <- i
 while (x > 7) 
 x <- i - 7
 
 day <- c(day, days[x])


cbind(dates,day)

r

share|improve this question

asked Mar 26 at 2:20

CauderCauder

1741111 bronze badges

add a comment | 

I have a list of every day from 2018-01-01 to 2018-06-01. It is a vector and it looks like this:

dates <- c("2018-01-01", "2018-01-02", "2018-01-03", ... , "2018-05-30", "2018-06-01")

I want to make a data frame where the first column has each of those dates and the second column has their day of the week. I am assuming that 2018-01-01 is a Monday.

date day
2018-01-01 Monday
2018-01-02 Tuesday
2018-01-03 Wednesday
... ...
2018-06-01 Monday

I'm working on a data frame towards that end, but I was curious for a better way to recycle through the days of the week than the solution I put together.

day <- NULL
for (i in 1:length(dates)) 
 x <- i
 while (x > 7) 
 x <- i - 7
 
 day <- c(day, days[x])


cbind(dates,day)

r

share|improve this question

asked Mar 26 at 2:20

CauderCauder

1741111 bronze badges

dates <- c("2018-01-01", "2018-01-02", "2018-01-03", ... , "2018-05-30", "2018-06-01")

date day
2018-01-01 Monday
2018-01-02 Tuesday
2018-01-03 Wednesday
... ...
2018-06-01 Monday

day <- NULL
for (i in 1:length(dates)) 
 x <- i
 while (x > 7) 
 x <- i - 7
 
 day <- c(day, days[x])


cbind(dates,day)

share|improve this question

asked Mar 26 at 2:20

CauderCauder

1741111 bronze badges

share|improve this question

asked Mar 26 at 2:20

CauderCauder

1741111 bronze badges

asked Mar 26 at 2:20

CauderCauder

1741111 bronze badges

asked Mar 26 at 2:20

CauderCauder

1741111 bronze badges

1 Answer
1

active

oldest

votes

0

We can use weekdays to get day of the week and put it in a dataframe.

data.frame(dates, day = weekdays(dates))

# dates day
#1 2018-01-01 Monday
#2 2018-01-02 Tuesday
#3 2018-01-03 Wednesday
#4 2018-05-30 Wednesday
#5 2018-06-01 Friday

EDIT

If we don't want to use any in-built function we can create a vector of days and lookup from there. Considering the first day is "Monday" we can use the modulo operator to find the relevant day for rest of the dates

days <- c("Monday","Tuesday","Wednesday","Thursday","Friday","Saturday","Sunday")

day <- days[(as.numeric(dates - dates[1]) %% 7) + 1]
day
#[1] "Monday" "Tuesday" "Wednesday" "Wednesday" "Friday" 

and then put them in dataframe

data.frame(dates, day)
# dates day
#1 2018-01-01 Monday
#2 2018-01-02 Tuesday
#3 2018-01-03 Wednesday
#4 2018-05-30 Wednesday
#5 2018-06-01 Friday

data

dates<-as.Date(c("2018-01-01","2018-01-02","2018-01-03","2018-05-30","2018-06-01"))

share|improve this answer

edited Mar 26 at 2:37

answered Mar 26 at 2:24

Ronak ShahRonak Shah

66.3k1010 gold badges4747 silver badges8080 bronze badges

• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  For reasons related to the project, I'm not allowed to use any 'magic functions'
  
  – Cauder
  Mar 26 at 2:28
  

  
  
  
  


• 
  
  
  

  
  1
  

  
  
  
  
  
  

  
  
  @Cauder how do you define a 'magic function' ?
  
  – Ronak Shah
  Mar 26 at 2:30
  

  
  
  
  


• 
  
  
  

  
  2
  

  
  
  
  
  
  

  
  
  I'm limited to just 'dplyr' and base packages.
  
  – Cauder
  Mar 26 at 2:41
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  @Cauder I have updated the answer. I hope this does not fall into your category of "magic function". weekdays is a base function.
  
  – Ronak Shah
  Mar 26 at 2:41
  
  

  
  
  
  


• 
  
  
  

  
  2
  

  
  
  
  
  
  

  
  
  it's called modulo operator, it gives the remainder after division. Try 12 %% 7, 12 %% 6.
  
  – Ronak Shah
  Mar 26 at 2:51
  

  
  
  
  

 | 
show 2 more comments

Your Answer

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0

We can use weekdays to get day of the week and put it in a dataframe.

data.frame(dates, day = weekdays(dates))

# dates day
#1 2018-01-01 Monday
#2 2018-01-02 Tuesday
#3 2018-01-03 Wednesday
#4 2018-05-30 Wednesday
#5 2018-06-01 Friday

EDIT

If we don't want to use any in-built function we can create a vector of days and lookup from there. Considering the first day is "Monday" we can use the modulo operator to find the relevant day for rest of the dates

days <- c("Monday","Tuesday","Wednesday","Thursday","Friday","Saturday","Sunday")

day <- days[(as.numeric(dates - dates[1]) %% 7) + 1]
day
#[1] "Monday" "Tuesday" "Wednesday" "Wednesday" "Friday" 

and then put them in dataframe

data.frame(dates, day)
# dates day
#1 2018-01-01 Monday
#2 2018-01-02 Tuesday
#3 2018-01-03 Wednesday
#4 2018-05-30 Wednesday
#5 2018-06-01 Friday

data

dates<-as.Date(c("2018-01-01","2018-01-02","2018-01-03","2018-05-30","2018-06-01"))

share|improve this answer

edited Mar 26 at 2:37

answered Mar 26 at 2:24

Ronak ShahRonak Shah

66.3k1010 gold badges4747 silver badges8080 bronze badges

• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  For reasons related to the project, I'm not allowed to use any 'magic functions'
  
  – Cauder
  Mar 26 at 2:28
  

  
  
  
  


• 
  
  
  

  
  1
  

  
  
  
  
  
  

  
  
  @Cauder how do you define a 'magic function' ?
  
  – Ronak Shah
  Mar 26 at 2:30
  

  
  
  
  


• 
  
  
  

  
  2
  

  
  
  
  
  
  

  
  
  I'm limited to just 'dplyr' and base packages.
  
  – Cauder
  Mar 26 at 2:41
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  @Cauder I have updated the answer. I hope this does not fall into your category of "magic function". weekdays is a base function.
  
  – Ronak Shah
  Mar 26 at 2:41
  
  

  
  
  
  


• 
  
  
  

  
  2
  

  
  
  
  
  
  

  
  
  it's called modulo operator, it gives the remainder after division. Try 12 %% 7, 12 %% 6.
  
  – Ronak Shah
  Mar 26 at 2:51
  

  
  
  
  

 | 
show 2 more comments

0

We can use weekdays to get day of the week and put it in a dataframe.

data.frame(dates, day = weekdays(dates))

# dates day
#1 2018-01-01 Monday
#2 2018-01-02 Tuesday
#3 2018-01-03 Wednesday
#4 2018-05-30 Wednesday
#5 2018-06-01 Friday

EDIT

If we don't want to use any in-built function we can create a vector of days and lookup from there. Considering the first day is "Monday" we can use the modulo operator to find the relevant day for rest of the dates

days <- c("Monday","Tuesday","Wednesday","Thursday","Friday","Saturday","Sunday")

day <- days[(as.numeric(dates - dates[1]) %% 7) + 1]
day
#[1] "Monday" "Tuesday" "Wednesday" "Wednesday" "Friday" 

and then put them in dataframe

data.frame(dates, day)
# dates day
#1 2018-01-01 Monday
#2 2018-01-02 Tuesday
#3 2018-01-03 Wednesday
#4 2018-05-30 Wednesday
#5 2018-06-01 Friday

data

dates<-as.Date(c("2018-01-01","2018-01-02","2018-01-03","2018-05-30","2018-06-01"))

share|improve this answer

edited Mar 26 at 2:37

answered Mar 26 at 2:24

Ronak ShahRonak Shah

66.3k1010 gold badges4747 silver badges8080 bronze badges

• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  For reasons related to the project, I'm not allowed to use any 'magic functions'
  
  – Cauder
  Mar 26 at 2:28
  

  
  
  
  


• 
  
  
  

  
  1
  

  
  
  
  
  
  

  
  
  @Cauder how do you define a 'magic function' ?
  
  – Ronak Shah
  Mar 26 at 2:30
  

  
  
  
  


• 
  
  
  

  
  2
  

  
  
  
  
  
  

  
  
  I'm limited to just 'dplyr' and base packages.
  
  – Cauder
  Mar 26 at 2:41
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  @Cauder I have updated the answer. I hope this does not fall into your category of "magic function". weekdays is a base function.
  
  – Ronak Shah
  Mar 26 at 2:41
  
  

  
  
  
  


• 
  
  
  

  
  2
  

  
  
  
  
  
  

  
  
  it's called modulo operator, it gives the remainder after division. Try 12 %% 7, 12 %% 6.
  
  – Ronak Shah
  Mar 26 at 2:51
  

  
  
  
  

 | 
show 2 more comments

We can use weekdays to get day of the week and put it in a dataframe.

data.frame(dates, day = weekdays(dates))

# dates day
#1 2018-01-01 Monday
#2 2018-01-02 Tuesday
#3 2018-01-03 Wednesday
#4 2018-05-30 Wednesday
#5 2018-06-01 Friday

EDIT

If we don't want to use any in-built function we can create a vector of days and lookup from there. Considering the first day is "Monday" we can use the modulo operator to find the relevant day for rest of the dates

days <- c("Monday","Tuesday","Wednesday","Thursday","Friday","Saturday","Sunday")

day <- days[(as.numeric(dates - dates[1]) %% 7) + 1]
day
#[1] "Monday" "Tuesday" "Wednesday" "Wednesday" "Friday" 

and then put them in dataframe

data.frame(dates, day)
# dates day
#1 2018-01-01 Monday
#2 2018-01-02 Tuesday
#3 2018-01-03 Wednesday
#4 2018-05-30 Wednesday
#5 2018-06-01 Friday

data

dates<-as.Date(c("2018-01-01","2018-01-02","2018-01-03","2018-05-30","2018-06-01"))

share|improve this answer

edited Mar 26 at 2:37

answered Mar 26 at 2:24

Ronak ShahRonak Shah

66.3k1010 gold badges4747 silver badges8080 bronze badges

data.frame(dates, day = weekdays(dates))

# dates day
#1 2018-01-01 Monday
#2 2018-01-02 Tuesday
#3 2018-01-03 Wednesday
#4 2018-05-30 Wednesday
#5 2018-06-01 Friday

days <- c("Monday","Tuesday","Wednesday","Thursday","Friday","Saturday","Sunday")

day <- days[(as.numeric(dates - dates[1]) %% 7) + 1]
day
#[1] "Monday" "Tuesday" "Wednesday" "Wednesday" "Friday" 

data.frame(dates, day)
# dates day
#1 2018-01-01 Monday
#2 2018-01-02 Tuesday
#3 2018-01-03 Wednesday
#4 2018-05-30 Wednesday
#5 2018-06-01 Friday

dates<-as.Date(c("2018-01-01","2018-01-02","2018-01-03","2018-05-30","2018-06-01"))

share|improve this answer

edited Mar 26 at 2:37

answered Mar 26 at 2:24

Ronak ShahRonak Shah

66.3k1010 gold badges4747 silver badges8080 bronze badges

answered Mar 26 at 2:24

Ronak ShahRonak Shah

66.3k1010 gold badges4747 silver badges8080 bronze badges

answered Mar 26 at 2:24

Ronak ShahRonak Shah

66.3k1010 gold badges4747 silver badges8080 bronze badges