Read Quarterly time series data as Dates in R
Year A B C D E F
1993-Q1 15.3 5.77 437.02 487.68 97 86.9
1993-Q2 13.5 5.74 455.2 504.5 94.7 85.4
1993-Q3 12.9 5.79 469.42 523.37 92.4 82.9
:::
2021-Q1 18.3 6.48 35680.82 29495.92 182.2 220.4
2021-Q2 7.9 6.46 36940.3 30562.03 180.4 218
Dataset1 <- read.csv('C:/Users/s/Desktop/R/intro/data/Dataset1.csv')
class(Dataset1)
[1] "data.frame"
time_series <- ts(Dataset1, start=1993, frequency = 4)
class(time_series)
[1] "mts" "ts" "matrix"
I don't know how to proceed from there to read my Year column as dates (quaterly) instead of numbers!
Date class does not work well with ts class. It is better to use year and quarter. Using the input shown reproducibly in the Note at the end use read.csv.zoo with yearqtr class and then convert it to ts. The strip.white is probably not needed but we added it just in case.
library(zoo)
z <- read.csv.zoo("Dataset1.csv", FUN = as.yearqtr, format = "%Y-Q%q",
strip.white = TRUE)
tt <- as.ts(z)
tt
## A B C D E F
## 1993 Q1 15.3 5.77 437.02 487.68 97.0 86.9
## 1993 Q2 13.5 5.74 455.20 504.50 94.7 85.4
## 1993 Q3 12.9 5.79 469.42 523.37 92.4 82.9
class(tt)
## [1] "mts" "ts" "matrix"
as.integer(time(tt)) # years
## [1] 1993 1993 1993
cycle(tt) # quarters
## Qtr1 Qtr2 Qtr3
## 1993 1 2 3
as.numeric(time(tt)) # time in years
## [1] 1993.00 1993.25 1993.50
If you did want to use Date class it would be better to use a zoo (or xts) series.
zd <- aggregate(z, as.Date, c)
zd
## A B C D E F
## 1993-01-01 15.3 5.77 437.02 487.68 97.0 86.9
## 1993-04-01 13.5 5.74 455.20 504.50 94.7 85.4
## 1993-07-01 12.9 5.79 469.42 523.37 92.4 82.9
If you want a data frame or xts object then fortify.zoo(z), fortify.zoo(zd), as.xts(z) or as.xts(zd) can be used depending on which one you want.
Note
Lines <- "Year,A,B,C,D,E,F
1993-Q1,15.3,5.77,437.02,487.68,97,86.9
1993-Q2,13.5,5.74,455.2,504.5,94.7,85.4
1993-Q3,12.9,5.79,469.42,523.37,92.4,82.9
"
cat(Lines, file = "Dataset1.csv")