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
## Min. : 1 (Add)ventures : 1 Min. : 0.340
## 1st Qu.:1252 @Properties : 1 1st Qu.: 0.770
## Median :2502 1-Stop Translation USA: 1 Median : 1.420
## Mean :2502 110 Consulting : 1 Mean : 4.612
## 3rd Qu.:3751 11thStreetCoffee.com : 1 3rd Qu.: 3.290
## Max. :5000 123 Exteriors : 1 Max. :421.480
## (Other) :4995
## Revenue Industry Employees
## Min. :2.000e+06 IT Services : 733 Min. : 1.0
## 1st Qu.:5.100e+06 Business Products & Services: 482 1st Qu.: 25.0
## Median :1.090e+07 Advertising & Marketing : 471 Median : 53.0
## Mean :4.822e+07 Health : 355 Mean : 232.7
## 3rd Qu.:2.860e+07 Software : 342 3rd Qu.: 132.0
## Max. :1.010e+10 Financial Services : 260 Max. :66803.0
## (Other) :2358 NA's :12
## City State
## New York : 160 CA : 701
## Chicago : 90 TX : 387
## Austin : 88 NY : 311
## Houston : 76 VA : 283
## San Francisco: 75 FL : 282
## Atlanta : 74 IL : 273
## (Other) :4438 (Other):2764
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:
# compare variables to one another
library(corrgram)
corrgram(inc, order=TRUE, lower.panel=panel.ellipse,
upper.panel=panel.pts, text.panel=panel.txt,
diag.panel=panel.minmax)
From the above, there appears to be a slight relationship between employees and revenue. I will explore that relationship further below:
# compare employees to revenue
library(ggplot2)
plot(inc$Employees, inc$Revenue, xlab = "Employees", ylab = "Revenue")
cor(inc$Employees, inc$Revenue, use = "complete.obs")
## [1] 0.2779332
As we can see, the correlation is very weak.
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.
# Answer Question 1 here
#load proper packages
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
#group states and count number in groups
states <- inc %>%
group_by(State) %>%
count(State)
head(states)
## # A tibble: 6 x 2
## # Groups: State [6]
## State n
## <fct> <int>
## 1 AK 2
## 2 AL 51
## 3 AR 9
## 4 AZ 100
## 5 CA 701
## 6 CO 134
#load packages
library(ggplot2)
#create ggplot object
x <- ggplot(states, aes(x=reorder(State, n), y=n, fill=n))
#create bar plot
x + geom_bar(stat="identity", width=0.3, position = position_dodge(width=.5)) + coord_flip() + labs(x = "State", y = "Number of Fastest Growing Companies")
California has the most fast growing companies. This is probably due to the tech boom in Silicon Valley. It would be interesting to compare each states fastest growing companies by industry and see which industry dominates which states and if tech companies are doing better in certain states. This info would be helpful to people starting a company, to see where they should be located to start that company.
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.
# Answer Question 2 here
head(arrange(states, desc(n)))
## # A tibble: 6 x 2
## # Groups: State [6]
## State n
## <fct> <int>
## 1 CA 701
## 2 TX 387
## 3 NY 311
## 4 VA 283
## 5 FL 282
## 6 IL 273
#select only cases with full data
inc <- inc[complete.cases(inc),]
#select only NY companies
ny = inc %>%
filter(State == "NY")
#check for outliers
head(arrange(ny, desc(Employees)))
## Rank Name Growth_Rate Revenue
## 1 4577 Sutherland Global Services 0.48 5.976e+08
## 2 4936 Coty 0.36 4.600e+09
## 3 4716 Westcon Group 0.44 3.800e+09
## 4 3899 Denihan Hospitality Group 0.71 2.808e+08
## 5 4363 TransPerfect 0.55 3.413e+08
## 6 1499 Sterling Infosystems 2.66 2.149e+08
## Industry Employees City State
## 1 Business Products & Services 32000 Pittsford NY
## 2 Consumer Products & Services 10000 New York NY
## 3 IT Services 3000 Tarrytown NY
## 4 Travel & Hospitality 2280 New York NY
## 5 Business Products & Services 2218 New York NY
## 6 Human Resources 2081 New York NY
#remove outliers
ny_norm = ny %>%
filter(Employees <= 2000)
#explore NY state jobs
y <- ggplot(ny_norm, aes(reorder(Industry, Employees, mean), Employees))
y <- y + geom_boxplot() + coord_flip() + labs(x = "Industry", y = "Employees")
y
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.
# Answer Question 3 here
#filter by industry and calculate revenue per employee
industry <- inc %>%
group_by(Industry) %>%
summarise(Revenue=sum(Revenue), Employees=sum(Employees)) %>%
mutate(AvgRev = Revenue/Employees)
z <- ggplot(industry, aes(x=reorder(Industry, AvgRev), y=AvgRev))
z + geom_bar(stat="identity") + coord_flip() + labs(x = "Industry", y = "Number of Employees")
We can see here that computer hardware has the highest rate of revenue per employee.