Data Visualization

A short description of the post.

1. Load the R packages we will use.

library(tidyverse)
library(echarts4r)
library(ggforce) #install  before using for the first time
library(hrbrthemes)
theme_set(theme_ipsum()) # set all of the plot themes 
library(tidyverse)
library(tidyquant)
library(ggforce)
library(hrbrthemes)

1. Quiz questions

• Replace all the instances of ‘SEE QUIZ’. These are inputs from your moodle quiz.

• Replace all the instances of ‘???’. These are answers on your moodle quiz.

• Run all the individual code chunks to make sure the answers in this file correspond with your quiz answers

• After you check all your code chunks run then you can knit it. It won’t knit until all the ??? are replaced

• The quiz assumes that you have watched the videos, downloaded (to your examples folder) and worked through the excersises in excersises_slides-73-108.rmd.

Question: e-charts-1

Create a bar chart that shows the average hours Americans spend on five activities by year. Use the timeline argument to create an animation that will animate through the years.

• spend_time contains 10 years of data on how many hours Americans spend each day on 5 activites

• read it into spent_time

spend_time  <- read_csv("https://estanny.com/static/week8/spend_time.csv")

Start with spend_time

• The group_by year

• THen create an e_chart that assigns the activity to the x-axis and will show activity by year (the variable that you grouped the data on)

• Then use e_timeline_opts to set autoPlay to TRUE

• THen use e_bar to represent the variable avg_hours with a bar chart

• Then use e_title to set the main title to ‘average hours Americans spend per day on each activity’

• Then remove the legend with e_legend

spend_time %>% 
  group_by(year)  %>% 
  e_charts(x = activity , timeline = TRUE)  %>% 
  e_timeline_opts(autoPlay = TRUE)  %>% 
  e_bar(serie = avg_hours)  %>% 
  e_title(text ='Average hours Americans spend per day on each activity')  %>% 
  e_legend(show = FALSE)  

---

Question: echarts-2

Create a line chart for the activities that American spend time on.

Start with spend_time

• Then use mutate to convert year from a number to a string (year-month-day) using mutate

  • first convert year to a string “201X-12-31” using the function paste
    • paste will paste each year to 12 and 31 (separated by -)

• Then use mutate to convert year from a character object to a date object using the ymd function from the lubridate package (part of the tidyverse, but not automatically loaded). ymd converts dates stored as characters to date objects

• Then group_by the variable activity (to get a line for each activity)

• Then initiate an e_charts object with year on the x-axis

• Then use e_line to add a line to the variable avg_hours

• Then use e_title to set the main title to ‘Average hours Americans spend per day on each activity’

• Then use e_legend (top = 40) to move the legend down (from the top)

spend_time  %>%
  mutate(year = paste(year, "12","31", sep = "-"))  %>% 
  mutate(year = lubridate::ymd(year))  %>% 
  group_by(activity)  %>%
  e_charts(x  = year)  %>% 
  e_line(serie = avg_hours)  %>% 
  e_tooltip()  %>% 
  e_title(text = 'Average hours Americans spend per day on each activity')  %>% 
  e_legend(top = 40) 

---

Question: modify slide 82

• Create a plot with the spend_time data

  • Assign year to the x-axis

  • assign avg_hours to the y-axis

  • assign activity to color

• ADD points with geom_point

• ADD geom_mark_ellipse

  • filter on activity == “leisure/sports”

  • description is “Americans spend the most time on leisure/sport”

ggplot(spend_time, aes(x = year, y = avg_hours, color = activity)) +
geom_point() +
geom_mark_ellipse(aes(filter = activity == "leisure/sports",
 description = "Americans spend on average more time each day on leisure/sports than the other activities"))

---

Question: tidyquant

Modify the tidyquant example in the video

Retrieve stock price for Google, ticker: GOOG, using tq_get

• from 2019-08-01 to 2020-07-28

• assign output to df

df  <- tq_get("GOOG", get = "stock.prices", 
          from = "2019-08-01", to = "2020-07-28")

Create a plot with the df data

• assign date to the x-axis

• assign close to the y-axis

• ADD a line with geom_line

• ADD geom_mark_ellipse

  • filter on a date to mark. Pick a date after looking at the line plot. Include the date in your Rmd code chunk.

  • include a description of something that happened on that date from the pandemic timeline. Include the description in your Rmd code chunk

  • fill the ellipse yellow

• ADD geom_mark_ellipse

  • filter on the date that had the minimum close price. Include that date in your Rmd code chunk.

  • include a description of something that happened on that date from the pandemic timeline. Include the description in your Rmd code chunk

  • color the ellipse red

• ADD labs

  • set the title to SEE QUIZ

  • set x to NULL

  • set y to “closing price per share”

  • set caption to “Source: https://en.wikipedia.org/wiki/Timeline_of_the_COVID-19_pandemic_in_the_United_States”

ggplot(df, aes(x = date, y = close)) +
  geom_line() +
  geom_mark_ellipse(aes(
    filter = date == "2020-02-21",
    description = "Stock is very high right before Covid-19 shuts down business"
  ), fill = "yellow") +
  geom_mark_ellipse(aes(
   filter = date == "2020-03-18",
    description = "Covid-19 shuts down businesses and causes the economy to crash"
  ), color = "red", ) +
  labs(
    title = "GOOGLE",
    x = NULL,
    y = "Closing price per share",
    caption = "Source: https://en.wikipedia.org/wiki/Timeline_of_the_COVID-19_pandemic_in_the_United_States"
  )

Save the previous plot to preview.png and add to the yaml chunk at the top

ggsave(filename = "preview.png", 
       path = here::here("_posts", "2021-04-13-data-visualization"))