Customizing a ggplot chart

ggplot2

#1

Hello,

I am trying to transfer a chart from Excel over to R. I have used that Excel chart for many years and am hoping to re-create it in R.

Here is some dummy data that I ave created for this example:

data <- structure(list(
  Month = structure(c(17167, 17198, 17226, 17257, 17287, 17318, 17348, 17379, 17410, 17440, 17471, 17501, 17532), class = "Date"), 
  Sales_Dollars = c(0.21, 0.24, 0.33, 0.35, 0.38, 0.35, 0.31, 0.26, 0.21, 0.14, 0.18, 0.27, 0.28), 
  Sales_Units = c(0.08, 0.12, 0.15, 0.15, 0.18, 0.18, 0.18, 0.18, 0.16, 0.17, 0.16, 0.24, 0.19), 
  Price_per_Unit = c(0.14, 0.13, 0.18, 0.19, 0.19, 0.17, 0.14, 0.08, 0.06, 0, 0.04, 0.05, 0.1)), 
  .Names = c("Month", "Sales_Dollars", "Sales_Units", "Price_per_Unit"), class = c("tbl_df", "tbl", "data.frame"), row.names = c(NA, -13L))

data

> data
# A tibble: 13 x 4
   Month      Sales_Dollars Sales_Units Price_per_Unit
   <date>             <dbl>       <dbl>          <dbl>
 1 2017-01-01         0.210      0.0800         0.140 
 2 2017-02-01         0.240      0.120          0.130 
 3 2017-03-01         0.330      0.150          0.180 
 4 2017-04-01         0.350      0.150          0.190 
 5 2017-05-01         0.380      0.180          0.190 
 6 2017-06-01         0.350      0.180          0.170 
 7 2017-07-01         0.310      0.180          0.140 
 8 2017-08-01         0.260      0.180          0.0800
 9 2017-09-01         0.210      0.160          0.0600
10 2017-10-01         0.140      0.170          0     
11 2017-11-01         0.180      0.160          0.0400
12 2017-12-01         0.270      0.240          0.0500
13 2018-01-01         0.280      0.190          0.100 

Here is the Excel based chart that I normally use:
Excel_Chart

This is the closest that I could get with R:

data_chart <- data %>%
  ggplot(aes(x=Month))+
  geom_col(aes(y=Price_per_Unit, color="Price_per_Unit")) +
  geom_line(aes(y=Sales_Dollars, color="Dollars")) +
  geom_line(aes(y=Sales_Units, color="Units"))+
  scale_y_continuous(labels = scales::percent) +
  scale_x_date(date_breaks = "1 month", date_labels = "%b-%y") + 
  geom_hline(aes(yintercept = 0)) +
  theme(axis.text.x = element_text(angle = 45, hjust = 1)) +
  ggtitle("Product A: Sales Growth Performance") +
  ylab("Percentage Change Y/Y")
data_chart

Rplot
...But I am still trying to figure out a few things:

a) Adding data labels at the end of each variable (the last value of each variable)
b) The ability to customize the colors of each variable using RGB values
c) How do I get rid of the borders along geom_col?
d) The legend seems very odd, any suggestions on fixing it?

A few additional notes:
a) I am deliberately mixing a column (geom_col) with a line chart (geom_line). This is because I feel that the "Dollars" and "Units" variables are similar types of data, while the Price_per_Unit variable is conceptually different from the other two but still important to keep in the same chart.

b) The data frame is currently in a "wide" format. If there are suggested ways to build a mixed line and column plot using "tall" data, I am very keen to learn those ideas as well.

I hope that this makes sense. Any help would be hugely appreciated!


#2

Link that might help ya understand:

The legend issue is tied to the bar color issue, namely you specify the color you want the bar to be with fill rather than color. For bars, color refers to the outline (hence the green above). Separating your fill and color variables will also fix the legend. Here's your example again:

library(ggplot2)
library(dplyr)

data <- structure(list(
  Month = structure(c(17167, 17198, 17226, 17257, 17287, 17318, 17348, 17379, 17410, 17440, 17471, 17501, 17532), class = "Date"), 
  Sales_Dollars = c(0.21, 0.24, 0.33, 0.35, 0.38, 0.35, 0.31, 0.26, 0.21, 0.14, 0.18, 0.27, 0.28), 
  Sales_Units = c(0.08, 0.12, 0.15, 0.15, 0.18, 0.18, 0.18, 0.18, 0.16, 0.17, 0.16, 0.24, 0.19), 
  Price_per_Unit = c(0.14, 0.13, 0.18, 0.19, 0.19, 0.17, 0.14, 0.08, 0.06, 0, 0.04, 0.05, 0.1)), 
  .Names = c("Month", "Sales_Dollars", "Sales_Units", "Price_per_Unit"), class = c("tbl_df", "tbl", "data.frame"), row.names = c(NA, -13L))

data_chart <- data %>%
  ggplot(aes(x=Month))+
  geom_col(aes(y=Price_per_Unit, fill="Price_per_Unit")) +
  geom_line(aes(y=Sales_Dollars, color="Dollars")) +
  geom_line(aes(y=Sales_Units, color="Units"))+
  scale_y_continuous(labels = scales::percent) +
  scale_x_date(date_breaks = "1 month", date_labels = "%b-%y") + 
  scale_fill_manual(values = "green",
                    labels = c("Price Per Unit")) + 
  scale_color_manual(values = c("blue", "purple")) + 
  geom_hline(aes(yintercept = 0)) +
  theme(axis.text.x = element_text(angle = 45, hjust = 1),
        legend.title = element_blank()) +
  ggtitle("Product A: Sales Growth Performance") +
  ylab("Percentage Change Y/Y") + 
  geom_text(aes(label = scales::percent(Sales_Dollars[length(Sales_Dollars)]),
                x = max(Month) + 15, 
                y = Sales_Dollars[length(Sales_Dollars)])) + 
  geom_text(aes(label = scales::percent(Sales_Units[length(Sales_Units)]),
                x = max(Month) + 15,
                y = Sales_Units[length(Sales_Units)]))

data_chart

and the plot:

Worth noting that the + 15 in the x-placement for the geom_text(s) was the result of trial and error, I'm sure there's a more mathematical way to do this.

Hopefully this helps!


#3

PS - you can add legend.position = "bottom" to the theme() argument if you prefer the legend on the bottom like the Excel example.


#4

@rywhale Thank you! I think this will solve most of my needs. Let me play with these for a bit, I am planning to check the "solved" button for your answer soon :smile:


#5

I made a few further modifications. here is what I have now:

library(ggplot2)
library(dplyr)

data <- structure(list(
  Month = structure(c(17167, 17198, 17226, 17257, 17287, 17318, 17348, 17379, 17410, 17440, 17471, 17501, 17532), class = "Date"), 
  Sales_Dollars = c(0.21, 0.24, 0.33, 0.35, 0.38, 0.35, 0.31, 0.26, 0.21, 0.14, 0.18, 0.27, 0.28), 
  Sales_Units = c(0.08, 0.12, 0.15, 0.15, 0.18, 0.18, 0.18, 0.18, 0.16, 0.17, 0.16, 0.24, 0.19), 
  Price_per_Unit = c(0.14, 0.13, 0.18, 0.19, 0.19, 0.17, 0.14, 0.08, 0.06, 0, 0.04, 0.05, 0.1)), 
  .Names = c("Month", "Sales_Dollars", "Sales_Units", "Price_per_Unit"), class = c("tbl_df", "tbl", "data.frame"), row.names = c(NA, -13L))

x_labels <- data$Month

data_chart_1 <- data %>%
  ggplot(aes(x=Month))+
  geom_col(aes(y=Price_per_Unit, fill="Price_per_Unit")) +
  geom_line(aes(y=Sales_Dollars, color="Dollars"),size=1) +
  geom_line(aes(y=Sales_Units, color="Units"), size=1)+
  scale_y_continuous(labels = scales::percent) +
  scale_x_date(breaks = x_labels, date_labels = "%b-%y") + 
  scale_fill_manual(values = "#99cc00", 
                    labels = c("Price Per Unit")) + 
  scale_color_manual(values = c("#822433", "#00a1de")) + 
  geom_hline(aes(yintercept = 0)) +
  theme(axis.text.x = element_text(angle = 45, hjust = 1),
        legend.title = element_blank(), 
        panel.background = element_rect(fill = "white"),
        panel.grid.major = element_line(colour = "#f2f2f2"),
        panel.border=element_rect(fill=NA),
        plot.caption = element_text(size = 8, hjust = 0, color="gray")) +
  ggtitle("Product A: Sales Growth Performance" ) +
  labs(y="Percentage Change Y/Y", x="", caption = "Source: Monthly Sales Report") +
  geom_text(aes(label = scales::percent(Sales_Dollars[length(Sales_Dollars)]),
                x = max(Month) + 25, 
                y = Sales_Dollars[length(Sales_Dollars)])) + 
  geom_text(aes(label = scales::percent(Sales_Units[length(Sales_Units)]),
                x = max(Month) + 25,
                y = Sales_Units[length(Sales_Units)])) + 
  geom_text(aes(label = scales::percent(Price_per_Unit[length(Price_per_Unit)]),
                x = max(Month) + 35,
                y = Price_per_Unit[length(Price_per_Unit)]))

data_chart_1

Rplot_end

Thanks again for your help @rywhale !!