Извлечение дат в R

Question

Я работаю с временными рядами в онлайн-режиме, поэтому мне нужно последовательно выводить даты (по одному). Я использовал:

dates<- seq(as.Date(today), by="days", length=10) 
dates[1] 
      [,1] 
2016-06-24 NA 

Я хотел бы, чтобы извлечь каждый элемент, как мы делаем в матрицах, например:

mat<- matrix(c(1,2),ncol=1, nrow=2) 
mat[1,1] 
[1] 1 

Как я могу просто получить часть даты т.е. 2016-06-24 путем индексации или в петле?

Answer 1

Пожалуйста, дайте мне знать, если я неверно истолковал ваш вопрос. Это взыскивает их последовательно и выводит его на экран:

dates<- seq(as.Date(Sys.Date()), by="days", length=10) 

for(i in 1:length(dates)){ 
    print(paste("I have extracted the following date:", dates[i])) 
} 

[1] "I have extracted the following date: 2016-06-25" 
[1] "I have extracted the following date: 2016-06-26" 
[1] "I have extracted the following date: 2016-06-27" 
[1] "I have extracted the following date: 2016-06-28" 
[1] "I have extracted the following date: 2016-06-29" 
[1] "I have extracted the following date: 2016-06-30" 
[1] "I have extracted the following date: 2016-07-01" 
[1] "I have extracted the following date: 2016-07-02" 
[1] "I have extracted the following date: 2016-07-03" 
[1] "I have extracted the following date: 2016-07-04" 

Answer 2

Используйте paste() функцию для печати всех их сразу с текстом и объединить его с dates объекта.

today <- Sys.Date() 
    today 
    # [1] "2016-06-26" 

    dates<- seq(as.Date(today), by="days", length=10) 
    dates 
    # [1] "2016-06-26" "2016-06-27" "2016-06-28" "2016-06-29" "2016-06-30" 
    # [6] "2016-07-01" "2016-07-02" "2016-07-03" "2016-07-04" "2016-07-05" 

    paste("I have extracted the following date: ",dates) 
    # [1] "I have extracted the following date: 2016-06-26" 
    # [2] "I have extracted the following date: 2016-06-27" 
    # [3] "I have extracted the following date: 2016-06-28" 
    # [4] "I have extracted the following date: 2016-06-29" 
    # [5] "I have extracted the following date: 2016-06-30" 
    # [6] "I have extracted the following date: 2016-07-01" 
    # [7] "I have extracted the following date: 2016-07-02" 
    # [8] "I have extracted the following date: 2016-07-03" 
    # [9] "I have extracted the following date: 2016-07-04" 
    #[10] "I have extracted the following date: 2016-07-05"