CODEWITHSUNDEEP
r
Michael Herman
Michael Herman

Reputation: 41

How to make factory fiscal quarters behave like dates

I’m putting together some functions to help summarize temporal data in fiscal quarters. Function I have will take a date—e.g. 2017-01-01—and spit out factored character value that corresponds—e.g. ”1Q2017”. I’m using my data to create graphs in ggplot. But since I factor the quarters, I can’t use attributes like geom_line() to connect my data points, like you would for dates.

Can I create a data type for quarters that displays as quarters but behaves like dates? How would I do this?

Upvotes: 0

Views: 347

Answers (3)

G. Grothendieck
G. Grothendieck

Reputation: 269654

The "yearqtr" class in zoo represents year/quarters but acts sort of like dates in so far as internally such objects are represented numerically as year + frac where frac is 0, 1/4, 2/4, 3/4 and one can perform arithmetic on them and they format as meaningful year/quarter strings and work with lines in ggplot2 (and classic graphics and lattice graphics). See ?yearqtr and ?scale_x_yearqtr.

library(ggplot2)
library(zoo)

# test data
dates <- c("2017-01-01", "2017-04-01")
values <- 1:2

z <- zoo(values, as.yearqtr(dates)) # test zoo object

# 1. classic graphics

plot(z, axat = "n") 
axis(1, at = time(z), labels = format(time(z), "%YQ%q"))

# 2. ggplot2 graphics

autoplot(z) + scale_x_yearqtr()

# 3. ggplot2 graphics using data frame with yearqtr

DF <- fortify.zoo(z) # test data frame
sapply(DF, class)
##     Index         z 
## "yearqtr" "integer" 

ggplot(DF, aes(Index, z)) + geom_line() + scale_x_yearqtr()

Upvotes: 1

tblznbits
tblznbits

Reputation: 6778

You just need to specify group=1 in aes.

library(tidyverse) # install.packages('tidyverse') if needed

dat = data_frame(date = seq.Date(as.Date('2017-01-01'), 
                                 as.Date('2017-12-31'), 
                                 length.out=365), 
                 x = rnorm(365))
dat = mutate(dat, qtr = paste0(lubridate::quarter(date), 'Q', lubridate::year(date)))
dat$qtr = as.factor(dat$qtr) # for similarity to your situation
dat %>%
    group_by(qtr) %>%
    summarise(n = sum(x)) %>%
    ggplot(aes(x=qtr, y=n, group=1)) +
    geom_line()

Upvotes: 0

manotheshark
manotheshark

Reputation: 4357

Taking the comment from @Jaap and incorporating with example graph:

library(ggplot2)
library(zoo)

df <- data.frame(date1 = c("2017-01-01", "2016-10-01", "2016-07-01"),
                 v1 = c(2, 4, 3))
df$date1 <- as.Date(df$date1)

ggplot(df, aes(x = date1, y = v1)) +
  geom_line() + 
  scale_x_date(name = "quarters",
               date_labels = as.yearqtr)

Upvotes: 0

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