Your turn

Use the box data from the package classdata

library(tidyverse)
library(classdata)

Are there any missing values in the dataset box?

summary(box) # there are missing values!
##       Rank        Rank.Last.Week      Movie           Distributor       
##  Min.   :  1.00   Min.   :  1.00   Length:32885       Length:32885      
##  1st Qu.: 24.00   1st Qu.: 20.00   Class :character   Class :character  
##  Median : 48.00   Median : 41.00   Mode  :character   Mode  :character  
##  Mean   : 49.16   Mean   : 43.82                                        
##  3rd Qu.: 73.00   3rd Qu.: 65.00                                        
##  Max.   :128.00   Max.   :128.00                                        
##  NA's   :137      NA's   :6269                                          
##      Gross               Change               Thtrs.         Per.Thtr.       
##  Min.   : -2928896   Min.   :-1230729.0   Min.   :   1.0   Min.   :-2928896  
##  1st Qu.:     3475   1st Qu.:     -57.0   1st Qu.:   4.0   1st Qu.:     530  
##  Median :    26275   Median :     -38.0   Median :  24.0   Median :     956  
##  Mean   :  1563419   Mean   :     -31.3   Mean   : 412.9   Mean   :    2070  
##  3rd Qu.:   234873   3rd Qu.:      -7.0   3rd Qu.: 211.2   3rd Qu.:    1889  
##  Max.   :357115007   Max.   :   44504.0   Max.   :4802.0   Max.   :  243390  
##                      NA's   :6294         NA's   :1        NA's   :1         
##   Total.Gross             Week                Date           
##  Min.   :        0   Min.   :     1.00   Min.   :2013-03-08  
##  1st Qu.:    80460   1st Qu.:     3.00   1st Qu.:2014-10-24  
##  Median :  1258670   Median :     6.00   Median :2016-06-17  
##  Mean   : 34116370   Mean   :    45.81   Mean   :2016-06-12  
##  3rd Qu.: 29358392   3rd Qu.:    11.00   3rd Qu.:2018-01-26  
##  Max.   :936658640   Max.   :105065.00   Max.   :2019-10-11  
##

What are the values of Rank when Rank.Last.Week is missing?

box %>% 
  filter(is.na(Rank.Last.Week)) %>% 
  head()
##   Rank Rank.Last.Week                          Movie         Distributor
## 1    2             NA              The Addams Family      United Artists
## 2    3             NA                     Gemini Man  Paramount Pictures
## 3    9             NA                           Jexi           Lionsgate
## 4   13             NA                       Parasite                Neon
## 5   16             NA                The Sky is Pink   Gravitas Ventures
## 6   25             NA Metallica & San Francisco S... Trafalgar Releasing
##      Gross Change Thtrs. Per.Thtr. Total.Gross Week       Date
## 1 30300007     NA   4007      7562    30300007    1 2019-10-11
## 2 20552372     NA   3642      5643    20552372    1 2019-10-11
## 3  3106730     NA   2332      1332     3106730    1 2019-10-11
## 4   384216     NA      3    128072      384216    1 2019-10-11
## 5   295550     NA    194      1523      295550    1 2019-10-11
## 6   144736     NA    157       922      907163    1 2019-10-11

What is the dimension of the data set box, when removing all missing values with the function na.omit()?

dim(box)
## [1] 32885    11
dim(na.omit(box)) # don't use na.omit
## [1] 26388    11

Why does the following statement fail? box$Rank.Last.Week <- na.omit(box$Rank.Last.Week)

There is a mismatch in the dimensions.