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:

Top Industries by Total Revenue:

# distinct industries 
inc %>%
  summarize(DISTINCT_INDUSTRIES = n_distinct(Industry))
##   DISTINCT_INDUSTRIES
## 1                  25
sum1 <- inc %>%
  group_by(Industry) %>%
  summarize(NUM_COMPANIES = n(),
            PCT_TOTAL_COMPANIES = n()/nrow(.),
            INDUSTRY_REVENUE = sum(Revenue),
            PCT_TOTAL_REVENUE = sum(Revenue)/ sum(inc$Revenue),
            INDUSTRY_EMPLOYEES = sum(Employees, na.rm = TRUE)) 

# top 10 industries
kable(
  sum1 %>%
    arrange(desc(INDUSTRY_REVENUE)) %>%
    top_n(.,10)
)
Industry NUM_COMPANIES PCT_TOTAL_COMPANIES INDUSTRY_REVENUE PCT_TOTAL_REVENUE INDUSTRY_EMPLOYEES
Business Products & Services 482 0.0963807 26367900000 0.1093374 117357
IT Services 733 0.1465707 20681300000 0.0857573 102788
Health 355 0.0709858 17863400000 0.0740725 82430
Consumer Products & Services 203 0.0405919 14956400000 0.0620183 45464
Financial Services 260 0.0519896 13150900000 0.0545316 47693
Food & Beverage 131 0.0261948 12911300000 0.0535381 65911
Manufacturing 256 0.0511898 12684000000 0.0525956 43942
Human Resources 196 0.0391922 9246100000 0.0383400 226980
Software 342 0.0683863 8140600000 0.0337559 51262
Security 73 0.0145971 3812800000 0.0158102 41059

Top States by Total Revenue:

sum2 <- inc %>%
  group_by(State) %>%
  summarize(NUM_COMPANIES = n(),
            PCT_TOTAL_COMPANIES = n()/nrow(.),
            INDUSTRY_REVENUE = sum(Revenue),
            PCT_TOTAL_REVENUE = sum(Revenue)/ sum(inc$Revenue),
            INDUSTRY_EMPLOYEES = sum(Employees, na.rm = TRUE)) 

# top 5 states
kable(
  sum2 %>%
  arrange(desc(INDUSTRY_REVENUE)) %>%
  top_n(.,5)
)
State NUM_COMPANIES PCT_TOTAL_COMPANIES INDUSTRY_REVENUE PCT_TOTAL_REVENUE INDUSTRY_EMPLOYEES
IL 273 0.0545891 33244300000 0.1378511 103266
CA 701 0.1401720 23457900000 0.0972707 161219
TX 387 0.0773845 22164200000 0.0919063 90765
NY 311 0.0621876 18260400000 0.0757187 84370
DE 16 0.0031994 676800000 0.0028064 68544

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.

p <- ggplot(inc, aes(x=fct_rev(fct_infreq(State)))) + 
  geom_histogram(stat="count") + 
  ggtitle("Distribution of Top 5000 Companies by State") +
  xlab("State") + ylab("Number of Companies") + 
  coord_flip() 

p

Question 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.

First, let’s subset our data to state with the 3rd most companies. We’ll also eliminate any records that have null values. We can see that the state we’re working with is NY:

thirdState <- inc %>% 
  add_count(State) %>% 
  arrange(desc(n)) %>%
  filter(State == unique(State)[3]) %>%
  select(-n) 

thirdState <- thirdState[complete.cases(thirdState), ]

unique(thirdState$State)
## [1] "NY"

Next, let’s take a look at each Industry separately. This will help us to identify any outliers (dots above or below the body of the boxplot). We can see that many of the Industries have some outliers in the dataset.

vals <- ggplot(thirdState %>% filter(complete.cases(.) == TRUE), aes(x=Industry, y=Employees)) + 
    geom_boxplot() +
  facet_wrap(~Industry, scale="free")

vals

Now we will define a function to remove the outliers from each Industry separately and apply it to our dataframe. We can confirm that our outliers are removed by checking the rowcounts of the original NY dataset to the new dataset.

# function to remove outliers
removeOutliers <- function(df){
  outliers <- boxplot.stats(df$Employees)$out
  df <- df %>%
    filter(!Employees %in% outliers)
  return(df)
}

# group data into separate dataframes based on Industry
groupedData <- thirdState %>% 
  group_by(Industry) %>%
  group_split()

# apply removeOutliers function to dataframe
finalData <- do.call("rbind", lapply(groupedData, removeOutliers))

paste0('Num rows in original dataset: ', nrow(thirdState), ' | Num rows in new dataset: ', nrow(finalData))
## [1] "Num rows in original dataset: 311 | Num rows in new dataset: 280"

Finally, we can create a plot that shows the average employment by industry:

ggplot(finalData, aes(x=reorder(Industry, Employees, mean), y=Employees)) + 
  stat_summary(fun="mean", geom="bar") + 
  ggtitle(paste0("Average number of employees by Industry for ",unique(finalData$State))) +
  xlab("Industry") + ylab("Employee Count") + 
  coord_flip() + 
  stat_summary(aes(label=round(..y..,2)), fun=mean, geom="text", vjust = 0.5, hjust = -0.05) +
  expand_limits(y = 300)

And similarly, we can create a plot that shows the median employment by industry:

# median  
ggplot(finalData, aes(x=reorder(Industry, Employees, median), y=Employees)) + 
  stat_summary(fun="median", geom="bar") + 
  ggtitle(paste0("Median number of employees by Industry for ",unique(finalData$State))) +
  xlab("Industry") + ylab("Employee Count") + 
  coord_flip() + 
  stat_summary(aes(label=round(..y..,2)), fun=median, geom="text", vjust = 0.5, hjust = -0.05)

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.

First, we can group our data by Industry and calculate the revenue by employee:

revByEmployee <- inc %>%
  group_by(Industry) %>%
  summarize(TOTAL_REVENUE = sum(Revenue, na.rm=TRUE),
            TOTAL_EMPLOYEES = sum(Employees, na.rm = TRUE),
            REV_PER_EMPLOYEE = sum(Revenue, na.rm=TRUE)/ sum(Employees, na.rm = TRUE)) %>%
  arrange(desc(REV_PER_EMPLOYEE)) %>%
  ungroup()

revByEmployee
## # A tibble: 25 x 4
##    Industry                     TOTAL_REVENUE TOTAL_EMPLOYEES REV_PER_EMPLOYEE
##    <chr>                                <dbl>           <int>            <dbl>
##  1 Computer Hardware              11885700000            9714         1223564.
##  2 Energy                         13771600000           26437          520921.
##  3 Construction                   13174300000           29099          452741.
##  4 Logistics & Transportation     14840500000           39994          371068.
##  5 Consumer Products & Services   14956400000           45464          328972.
##  6 Insurance                       2337900000            7339          318558.
##  7 Manufacturing                  12684000000           43942          288653.
##  8 Retail                         10257400000           37068          276718.
##  9 Financial Services             13150900000           47693          275741.
## 10 Environmental Services          2638800000           10155          259852.
## # ... with 15 more rows

Now, we can plot this information:

ggplot(revByEmployee, aes(x=reorder(Industry, REV_PER_EMPLOYEE), y=REV_PER_EMPLOYEE)) + 
  geom_bar(stat="identity") +
  ggtitle(paste0("Average revenue per employee by Industry for ",unique(finalData$State))) +
  xlab("Industry") + ylab("Revenue") + 
  coord_flip() + 
  stat_summary(aes(label=round(..y..,2)), geom="text", vjust = 0.5, hjust = -0.05) +
  expand_limits(y = 1500000)