Title

library(dplyr)

## Warning: package 'dplyr' was built under R version 3.6.2

## 
## 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(tidyr)

## Warning: package 'tidyr' was built under R version 3.6.1

library(ggplot2)

## Warning: package 'ggplot2' was built under R version 3.6.2

data(starwars)

###

starwars %>%
  mutate(human = case_when(species == "Human" ~ "Human",
                           species != "Human" ~ "Not Human")) %>%
  filter(gender %in% c("female", "male"), !is.na(human)) %>%
  ggplot(aes(height, fill = gender)) +
  facet_grid(. ~ human) +
  geom_density()

## Warning: Removed 4 rows containing non-finite values (stat_density).

##
ggplot(starwars)+
  geom_col(aes(x=gender, y=height, fill=gender))

## Warning: Removed 6 rows containing missing values (position_stack).