geom_line absent in plot

tidyverse
#1

I am trying to create a line plot with this df named total_sales. It's content is

date tot_amount
Jul-18 165275
Aug-18 158731
Sep-18 160522
Oct-18 164416
Nov-18 160234
Dec-18 167913
Jan-19 162642
Feb-19 150665
Mar-19 166265
Apr-19 159845
May-19 157368
Jun-19 160539

I wrote a code to plot a line graph showing total sales over time.
ggplot(data = total_sales_by_month_year, aes(x = month_year, y = total_sales)) +
geom_line() +
labs(title = "Total Sales by Month", x = "Month", y = "Total Sales")

But this is the plot that was displayed to me.

IMG_20230331_205059_480
IMG_20230331_205059_4801280×669 46.4 KB

The result above does not contain a geom_line.
I would appreciate help with this. Thanks

#2

Please post the output of

dput(total_sales_by_month_year)

I do not see a column named total_sales in your example data.

#3

Screenshots are disfavored to illustrate the problem, use a reprex. See the FAQ.

There should have been an error message

Do you need to adjust the group aesthetic

eventually leading to

library(ggplot2)

total_sales_by_month_year <- data.frame(
  date = c(
    "Ju-18", "Aug-18", "Sep-18",
    "Oct-18", "Nov-18", "Dec-18", "Jan-19", "Feb-19", "Mar-19",
    "Apr-19", "May-19", "Jun-19"
  ),
  tot_amount = c(
    165275, 158731, 160522,
    164416, 160234, 167913, 162642, 150665, 166265, 159845,
    157368, 160539
  )
)

ggplot(data = total_sales_by_month_year, aes(x = date, y = tot_amount, group = 1)) +
  geom_line() +
  labs(title = "Total Sales by Month", x = "Month", y = "Total Sales")

Created on 2023-03-31 with reprex v2.0.2

but it is something that seems to trip up everyone when they see it.

1 Like
#4

this is the output of the code
structure(list(month_year = structure(c(18444, 18475, 18506,
18536, 18567, 18597, 18262, 18293, 18322, 18353, 18383, 18414
), class = "Date"), total_sales = c(165275.3, 158731.05, 160522,
164415.7, 160233.7, 167913.4, 162642.3, 150665, 166265.2, 159845.1,
157367.65, 160538.6)), row.names = c(NA, -12L), class = c("tbl_df",
"tbl", "data.frame"))

#5

Here is what I get using the data you posted and your ggplot code. Does the same code work for you?

total_sales_by_month_year <- structure(list(month_year = structure(c(18444, 18475, 18506,
                                                                     18536, 18567, 18597, 18262, 18293, 18322, 18353, 18383, 18414
), class = "Date"), total_sales = c(165275.3, 158731.05, 160522,
                                    164415.7, 160233.7, 167913.4, 162642.3, 150665, 166265.2, 159845.1,
                                    157367.65, 160538.6)), row.names = c(NA, -12L), class = c("tbl_df",
                                                                                              "tbl", "data.frame"))
library(ggplot2)
ggplot(data = total_sales_by_month_year, aes(x = month_year, y = total_sales)) +
  geom_line() +
  labs(title = "Total Sales by Month", x = "Month", y = "Total Sales")

Created on 2023-03-31 with reprex v2.0.2

#6

it does, thanks. But i made this question as clear as possible so that i can get an answer, i'm currently on a project and the df is a subset of the df i am working with. Suppose you are working with a df that with columns date and total_amount_spent. I wrote a code that shows the total amount spent over then used the code to make a line plot. i kept on getting errors one of which is 'Do you need to adjust the group aesthetic'?. I would like to know what i am doing wrong and i would appreciate it if you can guide me.

#7

The subset will plot in the same manner as the set if the arguments to aes are identical. But if you are adding a var and using it in aes not necessarily. So, show the subset data as modified because guessing is bootless.

#8

Here is an example for you to walk through

library(tidyverse)

(good_df <- data.frame(x=1:3,
                       y=4:6))

ggplot(data=good_df,
       aes(x=x,
           y=y)) + geom_line()

(bad_df <- data.frame(x=letters[1:3],
                       y=4:6))

ggplot(data=bad_df,
       aes(x=x,
           y=y)) + geom_line()

# fixing with a group aesthetic
ggplot(data=bad_df,
       aes(x=x,
           y=y,
           group=1L)) + geom_line()

The key to understand is that while numbers have a 'natural ordering' and, dates also are numbers with a natural ordering. character strings do not for the purpose of graphing. a representation of 'dates' in a textual form might look to you as a date, but not be a date class numeric object, and so it will not be clear that the x coords can be related straightforwardly to justify connecting the points into lines.

while your dput() contained a data.frame with actual numeric date types, your opening post shows that you likely had a 'date appearing' textual type. at some point you did a conversion; but you havent considered that this is the reason for your initial lack of a line, and the post example shared ability to see a line.

hope it helps.

#9

yes, i made a conversion. i created a new column that contains the month and year (eg Jan 2018)from the date column (eg 01-01-2018) in my df. the new column's data type is chr. trying to make a line plot using this column doesnt work. what should i do ?

#10

A) Make your date column not be chr but be a date
Or
B) add an arbitrary single value group(as shown in my example code above)

1 Like
#11

It worked !. Thanks alot.