Principles of Data Visualization and Introduction to ggplot2

I have provided you with data about the 5,000 fastest growing companies in the US, as compiled by Inc. magazine. lets read this in:

inc <- read.csv("https://raw.githubusercontent.com/charleyferrari/CUNY_DATA_608/master/module1/Data/inc5000_data.csv", header= TRUE)

And lets preview this data:

head(inc)
##   Rank                         Name Growth_Rate   Revenue
## 1    1                         Fuhu      421.48 1.179e+08
## 2    2        FederalConference.com      248.31 4.960e+07
## 3    3                The HCI Group      245.45 2.550e+07
## 4    4                      Bridger      233.08 1.900e+09
## 5    5                       DataXu      213.37 8.700e+07
## 6    6 MileStone Community Builders      179.38 4.570e+07
##                       Industry Employees         City State
## 1 Consumer Products & Services       104   El Segundo    CA
## 2          Government Services        51     Dumfries    VA
## 3                       Health       132 Jacksonville    FL
## 4                       Energy        50      Addison    TX
## 5      Advertising & Marketing       220       Boston    MA
## 6                  Real Estate        63       Austin    TX
summary(inc)
##       Rank          Name            Growth_Rate         Revenue         
##  Min.   :   1   Length:5001        Min.   :  0.340   Min.   :2.000e+06  
##  1st Qu.:1252   Class :character   1st Qu.:  0.770   1st Qu.:5.100e+06  
##  Median :2502   Mode  :character   Median :  1.420   Median :1.090e+07  
##  Mean   :2502                      Mean   :  4.612   Mean   :4.822e+07  
##  3rd Qu.:3751                      3rd Qu.:  3.290   3rd Qu.:2.860e+07  
##  Max.   :5000                      Max.   :421.480   Max.   :1.010e+10  
##                                                                         
##    Industry           Employees           City              State          
##  Length:5001        Min.   :    1.0   Length:5001        Length:5001       
##  Class :character   1st Qu.:   25.0   Class :character   Class :character  
##  Mode  :character   Median :   53.0   Mode  :character   Mode  :character  
##                     Mean   :  232.7                                        
##                     3rd Qu.:  132.0                                        
##                     Max.   :66803.0                                        
##                     NA's   :12

Think a bit on what these summaries mean. Use the space below to add some more relevant non-visual exploratory information you think helps you understand this data:

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(psych)
glimpse(inc)
## Rows: 5,001
## Columns: 8
## $ Rank        <int> 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17,…
## $ Name        <chr> "Fuhu", "FederalConference.com", "The HCI Group", "Bridger…
## $ Growth_Rate <dbl> 421.48, 248.31, 245.45, 233.08, 213.37, 179.38, 174.04, 17…
## $ Revenue     <dbl> 1.179e+08, 4.960e+07, 2.550e+07, 1.900e+09, 8.700e+07, 4.5…
## $ Industry    <chr> "Consumer Products & Services", "Government Services", "He…
## $ Employees   <int> 104, 51, 132, 50, 220, 63, 27, 75, 97, 15, 149, 165, 250, …
## $ City        <chr> "El Segundo", "Dumfries", "Jacksonville", "Addison", "Bost…
## $ State       <chr> "CA", "VA", "FL", "TX", "MA", "TX", "TN", "CA", "UT", "RI"…

Glimpse is good for seeing the number of columns and their names. It also shows each column type. Plus, it give how many rows there are.

describe(inc)
##             vars    n        mean           sd    median     trimmed
## Rank           1 5001     2501.64      1443.51 2.502e+03     2501.73
## Name*          2 5001     2501.00      1443.81 2.501e+03     2501.00
## Growth_Rate    3 5001        4.61        14.12 1.420e+00        2.14
## Revenue        4 5001 48222535.49 240542281.14 1.090e+07 17334966.26
## Industry*      5 5001       12.10         7.33 1.300e+01       12.05
## Employees      6 4989      232.72      1353.13 5.300e+01       81.78
## City*          7 5001      732.00       441.12 7.610e+02      731.74
## State*         8 5001       24.80        15.64 2.300e+01       24.44
##                     mad     min        max      range  skew kurtosis         se
## Rank            1853.25 1.0e+00 5.0000e+03 4.9990e+03  0.00    -1.20      20.41
## Name*           1853.25 1.0e+00 5.0010e+03 5.0000e+03  0.00    -1.20      20.42
## Growth_Rate        1.22 3.4e-01 4.2148e+02 4.2114e+02 12.55   242.34       0.20
## Revenue     10674720.00 2.0e+06 1.0100e+10 1.0098e+10 22.17   722.66 3401441.44
## Industry*          8.90 1.0e+00 2.5000e+01 2.4000e+01 -0.10    -1.18       0.10
## Employees         53.37 1.0e+00 6.6803e+04 6.6802e+04 29.81  1268.67      19.16
## City*            604.90 1.0e+00 1.5190e+03 1.5180e+03 -0.04    -1.26       6.24
## State*            19.27 1.0e+00 5.2000e+01 5.1000e+01  0.12    -1.46       0.22

Descibe is like summary, with the difference that it is in table form and the descriptive stats are a little deeper with mad(median absolute deviation), skew, kurtosis and se(standard error).

colSums(is.na(inc))
##        Rank        Name Growth_Rate     Revenue    Industry   Employees 
##           0           0           0           0           0          12 
##        City       State 
##           0           0

One of the most important non visual exploratory questions that needs to be answered in every data set, is how many na’s there are.

Question 1

Create a graph that shows the distribution of companies in the dataset by State (ie how many are in each state). There are a lot of States, so consider which axis you should use. This visualization is ultimately going to be consumed on a ‘portrait’ oriented screen (ie taller than wide), which should further guide your layout choices.

library(ggplot2)
## 
## Attaching package: 'ggplot2'
## The following objects are masked from 'package:psych':
## 
##     %+%, alpha
companies_per_state <- inc %>%
  group_by(State) %>%
  count(State) 

head(companies_per_state,5)
## # A tibble: 5 × 2
## # Groups:   State [5]
##   State     n
##   <chr> <int>
## 1 AK        2
## 2 AL       51
## 3 AR        9
## 4 AZ      100
## 5 CA      701
companies_per_state %>%
  ggplot(aes(y=reorder(State, n), x=n)) +
  geom_bar(stat="identity",color='white',fill='blue') +
  ggtitle('Companies per State') +
  xlab("Number of Companies") + 
  ylab("State")

Quesiton 2

Lets dig in on the state with the 3rd most companies in the data set. Imagine you work for the state and are interested in how many people are employed by companies in different industries. Create a plot that shows the average and/or median employment by industry for companies in this state (only use cases with full data, use R’s complete.cases() function.) In addition to this, your graph should show how variable the ranges are, and you should deal with outliers.

companies_ny_state <- inc %>%
  filter(State=='NY') %>%
  filter(complete.cases(.))
mean_employees_per_industry <- companies_ny_state %>%
  group_by(Industry)%>%
  summarise(mean_employees = mean(Employees))

mean_max <- max(mean_employees_per_industry$mean_employees)
companies_max <- max(companies_ny_state$Employees)
ggplot(companies_ny_state, aes(x= reorder(Industry, Employees, mean), y=Employees)) + 
  geom_boxplot(width = 0.5, fill = "blue",  color="black", alpha=0.2) + 
  coord_flip() +
  geom_point(data = mean_employees_per_industry, aes(x=Industry, y=mean_employees, fill = "Mean Employees"),  color="red", size = 1, show.legend = TRUE) + 
  scale_y_continuous(expand = c(0,0), limits = c(0, mean_max + 50)) + 
  ggtitle("Distribution of Employees per Industry (New York State)") + 
  ylab("Employees") + 
  xlab("Industry") + 
  theme_bw() + 
  theme(plot.title = element_text(size=12, face="bold", hjust = 0.5, color = "black"),
        axis.text=element_text(size=10, face = "bold"),
        axis.title=element_text(size=10,face="bold", color = "black"),
        panel.background = element_blank(),
        panel.border = element_blank(),
        axis.line = element_line(color = "black", 
                      size = 0.5, linetype = "solid"),
        axis.ticks.y = element_blank(),
        axis.ticks.x = element_line(color="black"),
        legend.position = "top") 

Most companies employ less than 250 people as the bar charts show, but big companies skew the mean number of employee’s, especially in the top industries.

Question 3

Now imagine you work for an investor and want to see which industries generate the most revenue per employee. Create a chart that makes this information clear. Once again, the distribution per industry should be shown.

rev_per_employee <- inc %>%
  filter(complete.cases(.)) %>%
  group_by(Industry) %>% 
  summarise(rev_total = sum(Revenue), emp_total =  sum(Employees)) %>%
  mutate(rev_per_emp = rev_total / emp_total) %>% 
  arrange(desc(rev_per_emp))
head(rev_per_employee,5)
## # A tibble: 5 × 4
##   Industry                       rev_total emp_total rev_per_emp
##   <chr>                              <dbl>     <int>       <dbl>
## 1 Computer Hardware            11885700000      9714    1223564.
## 2 Energy                       13771600000     26437     520921.
## 3 Construction                 13174300000     29099     452741.
## 4 Logistics & Transportation   14837800000     39994     371001.
## 5 Consumer Products & Services 14956400000     45464     328972.
ggplot(rev_per_employee, aes(x = reorder(Industry, rev_per_emp), y = rev_per_emp)) +
  geom_bar(stat = "identity", fill = "blue") + 
  coord_flip() + 
  scale_y_continuous(expand = c(0, 0), limits = c(0, 1500000),breaks = c(0, 500000, 1000000), labels = scales::comma) + 
  ggtitle("Revenue per Employee by Industry ") +
  ylab("Revenue per Employee")+ 
  xlab("Industry")+ 
  geom_hline(yintercept=seq(0,1500000,250000), col="white", lwd=1) +
  geom_text(aes(label = scales::comma(round(rev_per_emp, 0))), vjust = 0.25, hjust = -0.2, fontface='bold', color="black") + 
  theme(plot.title = element_text(size=12, face="bold", color = "black"),
        axis.text=element_text(size=10, face = "bold"),
        axis.title=element_text(size=10,face="bold", color = "black"),
        panel.background = element_blank(),
        axis.line = element_line(color = "black", 
                      size = 0.75, linetype = "solid"),
        axis.ticks.y = element_blank(),
        axis.ticks.x = element_line(color="black"))
## Warning: Using `size` aesthetic for lines was deprecated in ggplot2 3.4.0.
## ℹ Please use `linewidth` instead.

If I were to advise the investor, then the top 3 industries by revenue generated per employee are, Computer Hardware, Energy and Construction. Computer Hardware generates the most revenue per employee at $1.2 million per employee. It generates 2.35 times more revenue per employee than Energy does and 2.7 time more revenue per employee than Construction does.