library(dplyr)
## 
## Attaching package: 'dplyr'
## The following objects are masked from 'package:stats':
## 
##     filter, lag
## The following objects are masked from 'package:base':
## 
##     intersect, setdiff, setequal, union
library(readr)

# Load the movies dataset
movies <- read_csv("https://gist.githubusercontent.com/tiangechen/b68782efa49a16edaf07dc2cdaa855ea/raw/0c794a9717f18b094eabab2cd6a6b9a226903577/movies.csv")
## Rows: 77 Columns: 8
## ── Column specification ────────────────────────────────────────────────────────
## Delimiter: ","
## chr (4): Film, Genre, Lead Studio, Worldwide Gross
## dbl (4): Audience score %, Profitability, Rotten Tomatoes %, Year
## 
## ℹ Use `spec()` to retrieve the full column specification for this data.
## ℹ Specify the column types or set `show_col_types = FALSE` to quiet this message.

1. rename(): (4 points)

Rename the “Film” column to “movie_title” and “Year” to “release_year”.

q1 <- movies %>%
  rename(movie_title = Film,
         release_year = Year)

head(q1)
## # A tibble: 6 × 8
##   movie_title               Genre `Lead Studio` `Audience score %` Profitability
##   <chr>                     <chr> <chr>                      <dbl>         <dbl>
## 1 Zack and Miri Make a Por… Roma… The Weinstei…                 70          1.75
## 2 Youth in Revolt           Come… The Weinstei…                 52          1.09
## 3 You Will Meet a Tall Dar… Come… Independent                   35          1.21
## 4 When in Rome              Come… Disney                        44          0   
## 5 What Happens in Vegas     Come… Fox                           72          6.27
## 6 Water For Elephants       Drama 20th Century…                 72          3.08
## # ℹ 3 more variables: `Rotten Tomatoes %` <dbl>, `Worldwide Gross` <chr>,
## #   release_year <dbl>

2. select(): (4 points)

Create a new data frame with only the columns: movie_title, release_year, Genre, Profitability,

q2 <- q1 %>%
  select(movie_title, release_year, Genre, Profitability)

head(q2) 
## # A tibble: 6 × 4
##   movie_title                        release_year Genre   Profitability
##   <chr>                                     <dbl> <chr>           <dbl>
## 1 Zack and Miri Make a Porno                 2008 Romance          1.75
## 2 Youth in Revolt                            2010 Comedy           1.09
## 3 You Will Meet a Tall Dark Stranger         2010 Comedy           1.21
## 4 When in Rome                               2010 Comedy           0   
## 5 What Happens in Vegas                      2008 Comedy           6.27
## 6 Water For Elephants                        2011 Drama            3.08

3. filter(): (4 points)

Filter the data set to include only movies released after 2000 with a Rotten Tomatoes % higher than 80.

q3 <- q2 %>%
  filter(release_year > 2000 & 'Rotten Tomatoes %' > 80)

head(q3)
## # A tibble: 6 × 4
##   movie_title                        release_year Genre   Profitability
##   <chr>                                     <dbl> <chr>           <dbl>
## 1 Zack and Miri Make a Porno                 2008 Romance          1.75
## 2 Youth in Revolt                            2010 Comedy           1.09
## 3 You Will Meet a Tall Dark Stranger         2010 Comedy           1.21
## 4 When in Rome                               2010 Comedy           0   
## 5 What Happens in Vegas                      2008 Comedy           6.27
## 6 Water For Elephants                        2011 Drama            3.08

4. mutate(): (4 points)

Add a new column called “Profitability_millions” that converts the Profitability to millions of dollars.

q4 <- q3 %>%
  mutate(Profitability_millions = Profitability/1e6)

head(q4)
## # A tibble: 6 × 5
##   movie_title            release_year Genre Profitability Profitability_millions
##   <chr>                         <dbl> <chr>         <dbl>                  <dbl>
## 1 Zack and Miri Make a …         2008 Roma…          1.75             0.00000175
## 2 Youth in Revolt                2010 Come…          1.09             0.00000109
## 3 You Will Meet a Tall …         2010 Come…          1.21             0.00000121
## 4 When in Rome                   2010 Come…          0                0         
## 5 What Happens in Vegas          2008 Come…          6.27             0.00000627
## 6 Water For Elephants            2011 Drama          3.08             0.00000308

5. arrange(): (3 points)

Sort the filtered data set by Rotten Tomatoes % in descending order, and then by Profitability in descending order. five <- four %>% arrange(desc(Rotten Tomatoes %) , desc(Profitability_millions))

q5 <- q4 %>%
  arrange(desc('Audience score %'),desc(Profitability_millions))

head(q5)
## # A tibble: 6 × 5
##   movie_title            release_year Genre Profitability Profitability_millions
##   <chr>                         <dbl> <chr>         <dbl>                  <dbl>
## 1 Fireproof                      2008 Drama         66.9              0.0000669 
## 2 High School Musical 3…         2008 Come…         22.9              0.0000229 
## 3 The Twilight Saga: Ne…         2009 Drama         14.2              0.0000142 
## 4 Waitress                       2007 Roma…         11.1              0.0000111 
## 5 Twilight                       2008 Roma…         10.2              0.0000102 
## 6 Mamma Mia!                     2008 Come…          9.23             0.00000923

6. Combining functions: (3 points)

Use the pipe operator (%>%) to chain these operations together, starting with the original dataset and ending with a final dataframe that incorporates all the above transformations.

movies %>%
  rename(movie_title = Film,
         release_year = Year) %>%
  select(movie_title, release_year, Genre, Profitability) %>%
  filter(release_year > 2000 & 'Audience score %' > 80) %>%
  mutate(Profitability_millions = 1000000 * Profitability) %>%
  arrange(desc('Audience score %'),desc(Profitability_millions)) %>%
head(5)
## # A tibble: 5 × 5
##   movie_title            release_year Genre Profitability Profitability_millions
##   <chr>                         <dbl> <chr>         <dbl>                  <dbl>
## 1 Fireproof                      2008 Drama          66.9              66934000 
## 2 High School Musical 3…         2008 Come…          22.9              22913136.
## 3 The Twilight Saga: Ne…         2009 Drama          14.2              14196400 
## 4 Waitress                       2007 Roma…          11.1              11089742.
## 5 Twilight                       2008 Roma…          10.2              10180027.

7. Interpret question 6 (1 point)

EXTRA CREDIT (4 points)

Create a summary dataframe that shows the average rating and Profitability_millions for movies by Genre. Hint: You’ll need to use group_by() and summarize().

library(dplyr)

movies <- movies %>%
  rename(Audience_score = `Audience score %`)  

EX <- movies %>%
  mutate(Profitability_millions = Profitability / 1e6) %>%
  group_by(Genre) %>% 
  summarize(
    Avg_Rating = mean(Audience_score, na.rm = TRUE),
    Avg_Profitability_millions = mean(Profitability_millions, na.rm = TRUE)
  )

head(EX)
## # A tibble: 6 × 3
##   Genre     Avg_Rating Avg_Profitability_millions
##   <chr>          <dbl>                      <dbl>
## 1 Action          45                   0.00000125
## 2 Animation       70.2                 0.00000376
## 3 Comdy           61                   0.00000265
## 4 Comedy          61.0                 0.00000378
## 5 Drama           67.2                 0.00000841
## 6 Fantasy         81                   0.00000178