R Visualizations: Derive Meaning from Data

252 Pages·2020·15.535 MB·English

by  David Gerbing

R Visualizations

R Visualizations
Derive Meaning from Data
David W. Gerbing
The School of Business
Portland State University
Firsteditionpublished2020
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Names: Gerbing,DavidW.,author.
Title: Rvisualizations: derivemeaningfromdata/DavidW.Gerbing,TheSchoolof
Business,PortlandStateUniversity.
Description: 1st. |BocaRaton: CRCPress,2020. |Includesbibliographicalreferences
andindex.
Identifiers: LCCN2020004865|ISBN9781138599635(hardback)|
ISBN9780429470837(ebook)
Subjects: LCSH:Informationvisualization. |R(Computerprogramlanguage)
Classification: LCCQA76.9.I52G472020|DDC001.4/226--dc23
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ISBN:978-1-138-59963-5(hbk)
ISBN:978-0-429-47083-7(ebk)
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Contents
Preface xi
1 Visualize Data 1
1.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
1.1.1 Visualization and Analytics . . . . . . . . . . . . . . . . . . . 2
1.1.2 Open-Source Software for Data Visualization . . . . . . . . . 3
1.2 Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
1.2.1 R Objects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
1.2.2 Employee Data Example . . . . . . . . . . . . . . . . . . . . . 7
1.2.3 Types of Variables . . . . . . . . . . . . . . . . . . . . . . . . 9
1.2.4 Read Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
1.2.5 Variable Labels . . . . . . . . . . . . . . . . . . . . . . . . . . 18
1.2.6 Categorical Variables as Factors . . . . . . . . . . . . . . . . 19
1.2.7 Save the Data Frame . . . . . . . . . . . . . . . . . . . . . . . 22
2 Visualization Quick Start 25
2.1 Visualization Systems . . . . . . . . . . . . . . . . . . . . . . . . . . 26
2.1.1 Relative Advantages of ggplot2 and lessR . . . . . . . . . . 26
2.1.2 Grayscale . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
2.2 Distribution of a Categorical Variable . . . . . . . . . . . . . . . . . 28
2.2.1 Bar Chart of a Single Variable . . . . . . . . . . . . . . . . . 28
2.2.2 Bar Charts of Multiple Variables . . . . . . . . . . . . . . . . 32
2.3 Distribution of a Continuous Variable . . . . . . . . . . . . . . . . . 35
2.3.1 Default Histogram . . . . . . . . . . . . . . . . . . . . . . . . 35
2.3.2 Beyond the Histogram . . . . . . . . . . . . . . . . . . . . . . 36
v
vi CONTENTS
2.4 Relation between Two Variables . . . . . . . . . . . . . . . . . . . . . 38
2.4.1 Basic Scatterplot . . . . . . . . . . . . . . . . . . . . . . . . . 38
2.4.2 Enhanced Scatterplot . . . . . . . . . . . . . . . . . . . . . . 39
2.5 Distribution of Values over Time . . . . . . . . . . . . . . . . . . . . 40
2.5.1 Time Series . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
2.5.2 Multiple Time Series . . . . . . . . . . . . . . . . . . . . . . . 42
3 Visualize a Categorical Variable 45
3.1 Bars, Dots, and Bubbles . . . . . . . . . . . . . . . . . . . . . . . . . 46
3.1.1 Horizontal Bar Chart of Counts . . . . . . . . . . . . . . . . . 47
3.1.2 Cleveland Dot Plot of Counts . . . . . . . . . . . . . . . . . . 48
3.1.3 Bubble Plot of Counts . . . . . . . . . . . . . . . . . . . . . . 49
3.1.4 Display Proportions . . . . . . . . . . . . . . . . . . . . . . . 50
3.2 Multiple Plots on a Single Panel . . . . . . . . . . . . . . . . . . . . 52
3.3 Provide the Numerical Values . . . . . . . . . . . . . . . . . . . . . . 54
3.3.1 Bar Chart of Individual Data Values . . . . . . . . . . . . . . 55
3.3.2 Vertical Long Value Labels . . . . . . . . . . . . . . . . . . . 56
3.3.3 Cleveland Dot Plot of Individual Data Values . . . . . . . . . 57
3.3.4 Visualize Means across Categories . . . . . . . . . . . . . . . 58
3.4 Communicate with Bar Fill Color . . . . . . . . . . . . . . . . . . . . 61
3.4.1 Bar Fill Color Bifurcated by Value of Mean Deviations . . . . 62
3.4.2 Bar Chart of an Ordinal Variable . . . . . . . . . . . . . . . . 64
3.4.3 Custom Color for Individual Bars. . . . . . . . . . . . . . . . 67
3.5 Create a Report from Saved Output . . . . . . . . . . . . . . . . . . 69
3.6 Part-Whole Visualizations . . . . . . . . . . . . . . . . . . . . . . . . 70
3.6.1 Doughnut and Pie Charts . . . . . . . . . . . . . . . . . . . . 71
3.6.2 The Waffle Plot . . . . . . . . . . . . . . . . . . . . . . . . . . 72
3.6.3 The Treemap . . . . . . . . . . . . . . . . . . . . . . . . . . . 73
CONTENTS vii
4 Visualize a Continuous Variable 79
4.1 Histogram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80
4.1.1 Binning Continuous Data . . . . . . . . . . . . . . . . . . . . 80
4.1.2 Histogram Artifacts . . . . . . . . . . . . . . . . . . . . . . . 82
4.1.3 Cumulative Histogram . . . . . . . . . . . . . . . . . . . . . . 83
4.1.4 Frequency Polygon . . . . . . . . . . . . . . . . . . . . . . . . 85
4.2 Density Plot . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85
4.2.1 Enhanced Density Plot . . . . . . . . . . . . . . . . . . . . . 86
4.2.2 Overlapping Density Curves . . . . . . . . . . . . . . . . . . . 87
4.2.3 Rug Plot . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90
4.2.4 Violin Plot . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90
4.3 Box Plot . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91
4.3.1 Classic Box Plot . . . . . . . . . . . . . . . . . . . . . . . . . 92
4.3.2 Box Plot Adjusted for Asymmetry . . . . . . . . . . . . . . . 93
4.4 One-Variable Scatterplot . . . . . . . . . . . . . . . . . . . . . . . . . 94
4.5 Integrated Violin/Box/Scatterplot . . . . . . . . . . . . . . . . . . . 94
4.5.1 VBS Plot . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95
4.5.2 VBS Plot of Likert Data . . . . . . . . . . . . . . . . . . . . . 97
4.5.3 Trellis Plots or Facets . . . . . . . . . . . . . . . . . . . . . . 98
4.6 Pareto Chart . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99
5 Visualize the Relation of Two Continuous Variables 103
5.1 Enhance the Scatterplot . . . . . . . . . . . . . . . . . . . . . . . . . 104
5.1.1 The Ellipse . . . . . . . . . . . . . . . . . . . . . . . . . . . . 104
5.1.2 Line of Best Fit . . . . . . . . . . . . . . . . . . . . . . . . . . 107
5.1.3 Annotate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 109
viii CONTENTS
5.2 Consideration of a Third Variable . . . . . . . . . . . . . . . . . . . . 112
5.2.1 Map Data from a Grouping Variable to Aesthetics . . . . . . 112
5.2.2 Trellis (Facet) Scatterplots . . . . . . . . . . . . . . . . . . . 115
5.2.3 Map a Third Continuous Variable into a Visual Aesthetic . . 117
5.2.4 Plot Multiple Variables on the Same Panel . . . . . . . . . . 119
5.3 Inter-Relations of a Set of Variables . . . . . . . . . . . . . . . . . . 120
5.3.1 Scatterplot Matrix . . . . . . . . . . . . . . . . . . . . . . . . 120
5.3.2 Heat Map of a Correlation Matrix . . . . . . . . . . . . . . . 122
5.4 Scatterplots for Large Data Sets . . . . . . . . . . . . . . . . . . . . 131
5.4.1 Smoothed Scatterplots . . . . . . . . . . . . . . . . . . . . . . 131
5.4.2 Contoured and Hex-Binned Scatterplots . . . . . . . . . . . . 132
6 Visualize Multiple Categorical Variables 135
6.1 Two Categorical Variables . . . . . . . . . . . . . . . . . . . . . . . . 136
6.1.1 Stacked Two-Variable Bar Chart . . . . . . . . . . . . . . . . 136
6.1.2 Unstacked Two-Variable Bar Chart . . . . . . . . . . . . . . . 138
6.1.3 Trellis Plots or Facets . . . . . . . . . . . . . . . . . . . . . . 139
6.2 Other Styles for the Two-Variable Bar Chart . . . . . . . . . . . . . 141
6.2.1 Sorted Two-Variable Bar Chart . . . . . . . . . . . . . . . . . 141
6.2.2 Horizontal Bar Chart . . . . . . . . . . . . . . . . . . . . . . 142
6.2.3 Bar Chart with Legend on the Top . . . . . . . . . . . . . . . 142
6.2.4 100% Stacked Bar Chart . . . . . . . . . . . . . . . . . . . . . 143
6.2.5 Bar Chart of Means across Two Categorical Variables . . . . 144
6.2.6 Two-Variable Cleveland Dot Plot . . . . . . . . . . . . . . . . 147
6.2.7 Paired t-test Visualization . . . . . . . . . . . . . . . . . . . . 148
6.3 Mosaic Plots and Association Plots . . . . . . . . . . . . . . . . . . . 150
6.3.1 The Mosaic Plot . . . . . . . . . . . . . . . . . . . . . . . . . 150
CONTENTS ix
6.3.2 Independence and Pearson Residuals . . . . . . . . . . . . . . 153
6.3.3 The Association Plot . . . . . . . . . . . . . . . . . . . . . . . 155
7 Visualize over Time 157
7.1 Run Chart and Control Chart . . . . . . . . . . . . . . . . . . . . . . 158
7.1.1 Run Chart . . . . . . . . . . . . . . . . . . . . . . . . . . . . 158
7.1.2 Control Chart. . . . . . . . . . . . . . . . . . . . . . . . . . . 160
7.2 Time Series . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 163
7.2.1 Filled Area Time Series . . . . . . . . . . . . . . . . . . . . . 163
7.2.2 Stacked Multiple Time Series . . . . . . . . . . . . . . . . . . 165
7.2.3 Formatted Multi-Panel Time Series. . . . . . . . . . . . . . . 166
7.2.4 Data Preparation for Date Variables . . . . . . . . . . . . . . 168
7.3 Forecasts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 172
7.3.1 Time-Series Object . . . . . . . . . . . . . . . . . . . . . . . . 172
7.3.2 Seasonal/Trend Decomposition . . . . . . . . . . . . . . . . . 173
7.3.3 Generate a Forecast . . . . . . . . . . . . . . . . . . . . . . . 176
8 Visualize Maps and Networks 179
8.1 Maps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 180
8.1.1 Map the World . . . . . . . . . . . . . . . . . . . . . . . . . . 180
8.1.2 Raster Images . . . . . . . . . . . . . . . . . . . . . . . . . . 183
8.1.3 Online Geocode Databases . . . . . . . . . . . . . . . . . . . 184
8.1.4 Create a Country Map with Cities . . . . . . . . . . . . . . . 187
8.1.5 Choropleth Map . . . . . . . . . . . . . . . . . . . . . . . . . 189
8.2 Network Visualizations . . . . . . . . . . . . . . . . . . . . . . . . . . 191
8.2.1 Network Data . . . . . . . . . . . . . . . . . . . . . . . . . . . 192
8.2.2 Visualizations . . . . . . . . . . . . . . . . . . . . . . . . . . . 193
8.2.3 Network Analysis . . . . . . . . . . . . . . . . . . . . . . . . . 196