Create a histogram showing month and year

August 9, 2022

I can create only a histogram with month or year seperately but not with month and year at the same time in the x-axis.

This is the data I have

Year	Month	stroke_victims
2005	1	40
2005	2	50
2005	3	48
2005	4	52
2005	5	32
2005	6	21
2005	7	23
2005	8	56
2005	9	43
2005	10	11
2005	11	12
2005	12	15
2006	1	40
2006	2	50
2006	3	48
2006	4	52
2006	5	32
2006	6	21
2006	7	23
2006	8	56
2006	9	43
2006	10	11
2006	11	12
2006	12	15
2007	1	40
2007	2	50
2007	3	48
2007	4	52
2007	5	32
2007	6	21
2007	7	23
2007	8	56
2007	9	43
2007	10	11
2007	11	12
2007	12	15

For year the code is like this

ggplot(stroke,aes(x=Year,y=stroke_victims)) + geom_bar(stat="identity") + ggtitle("Stroke victim patterns across the year 2005-2007")

For year the code is like this

ggplot(stroke,aes(x=Month,y=stroke_victims)) + geom_bar(stat="identity") + ggtitle("Stroke victim patterns by Months")

Is it possible to create a code which show january 2005, then february 2005 and so on and with the month name?

>Solution :

There are two ways to get the month name:

stroke$Month_text <- month.abb[stroke$Month]
head(stroke)
#   Year Month stroke_victims Month_text
# 1 2005     1             40        Jan
# 2 2005     2             50        Feb
# 3 2005     3             48        Mar
# 4 2005     4             52        Apr
# 5 2005     5             32        May
# 6 2005     6             21        Jun

or one can convert it to a date and use format(.., format="%B") (see ?strptime for %-codes). I’ll use month.abb for now.

From here, we can facet on Month_text. However, it’s going to be sorted lexicographically which is incorrect:

ggplot(stroke,aes(x=Month_text,y=stroke_victims)) +
  geom_bar(stat="identity") +
  ggtitle("Stroke victim patterns by Months") +
  facet_grid(Year ~ .)

With any question in ggplot2 that includes "order of …", we use factors.

stroke$Month_text <- factor(month.abb[stroke$Month], levels = month.abb)
ggplot(...) + ... # unchanged from above

Data

stroke <- structure(list(Year = c(2005L, 2005L, 2005L, 2005L, 2005L, 2005L, 2005L, 2005L, 2005L, 2005L, 2005L, 2005L, 2006L, 2006L, 2006L, 2006L, 2006L, 2006L, 2006L, 2006L, 2006L, 2006L, 2006L, 2006L, 2007L, 2007L, 2007L, 2007L, 2007L, 2007L, 2007L, 2007L, 2007L, 2007L, 2007L, 2007L), Month = c(1L, 2L, 3L, 4L, 5L, 6L, 7L, 8L, 9L, 10L, 11L, 12L, 1L, 2L, 3L, 4L, 5L, 6L, 7L, 8L, 9L, 10L, 11L, 12L, 1L, 2L, 3L, 4L, 5L, 6L, 7L, 8L, 9L, 10L, 11L, 12L), stroke_victims = c(40L, 50L, 48L, 52L, 32L, 21L, 23L, 56L, 43L,  11L, 12L, 15L, 40L, 50L, 48L, 52L, 32L, 21L, 23L, 56L, 43L, 11L, 12L, 15L, 40L, 50L, 48L, 52L, 32L, 21L, 23L, 56L, 43L, 11L, 12L, 15L), Month_text = structure(c(1L, 2L, 3L, 4L, 5L, 6L, 7L, 8L, 9L, 10L, 11L, 12L, 1L, 2L, 3L, 4L, 5L, 6L, 7L, 8L, 9L, 10L, 11L, 12L, 1L, 2L, 3L, 4L, 5L, 6L, 7L, 8L, 9L, 10L, 11L, 12L), .Label = c("Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"), class = "factor")), row.names = c(NA, -36L), class = "data.frame")