DSC 201: Data Analysis & Visualization

Transcription

1 DSC 201: Data Analysis & Visualization Visualization Tools Dr. David Koop

2 Visualization for Exploration 2

3 MTA Fare Data Exploration 3

4 MTA Fare Data Exploration 4

5 MTA Fare Data Exploration 5

6 MTA Fare Data Exploration 5

7 MTA Fare Data Exploration 6

8 MTA Fare Data Exploration 7

9 MTA Fare Data Exploration A UGUST S U N M O N T U E W E D T H U F R I S A T :10 1 1: :10 3 8:40 YES YES YES 1 T OR 4 SD 11 DET 18 BOS 25 TB DET 5 CHW 12 LAA 19 TOR 26 TOR DET 6 CHW 13 LAA 20 TOR 27 TOR HOU 7 CHW 14 LAA 21 TOR 28 TOR DET 8 COL 15 LAA 22 TOR 29 TOR SD 9 DET 16 BOS 23 TB 30 BAL SD 10 DET 17 BOS 24 TB 31 BAL 4:10 8:10 8:10 8:10 1:10 7:05 1:05 YES YES MY9 YES YES YES YES TBA 7:05 7:05 7:05 1:05 7:10 4:05 TBA YES YES YES YES MY9 FOX TBA 1:10 7:05 7:05 1:05 7:10 7:10 TBA YES MY9 YES YES MY9 YES 1:40 7:07 7:07 7:07 7:07 7:05 1:05 YES YES YES YES YES YES YES S EPT EMBER S U N M O N T U E W E D T H U F R I S A T 1:05 2 1:05 3 7:05 4 7:05 5 7:05 6 7:05 7 1:05 YES YES YES YES YES YES FOX 1 BAL 8 BOS 15 BOS 22 SF 29 HOU CHW CHW CHW BOS BOS 9 BAL 7:05 10 BAL 11 BAL 12 BAL 13 BOS 16 1: TOR TOR TOR TOR SF 23 1:10 YES TB TB TB TB HOU 30 1:10 YES ALL GAMES ARE EASTERN TIME. HOU HOU CHW CHW T OR BOS 14 BOS 21 SF 28 HOU 30 T OR TBA 7:05 7:05 7:05 7:10 1:05 TBA YES MY9 YES YES MY9 FOX TBA 7:07 2:10 1:10 7:07 7:07 7:05 TBA TBA YES MY9 YES YES YES TBA 1:05 7:05 7:05 7:05 8:10 TBA YES YES MY9 YES YES YES TBA R EGULAR SE ASON SCHED ULE 7

10 Visualization for Explanation 8

11 Design Iteration 9

12 Definition Computer-based visualization systems provide visual representations of datasets designed to help people carry out tasks more effectively. T. Munzner 10

13 Definition Computer-based visualization systems provide visual representations of datasets designed to help people carry out tasks more effectively. 11

14 Definition NYC Subway Fare Data Computer-based visualization systems provide visual representations of datasets designed to help people carry out tasks more effectively. 11

15 Definition NYC Subway Fare Data Computer-based visualization systems provide visual representations of datasets designed to help people carry out tasks more effectively. Find Interesting NYC Subway Ridership Patterns 11

16 Definition Computer-based visualization systems provide visual representations of datasets designed to help people carry out tasks more effectively. 12

17 Computers Helping People [Cerebral, Barsky et al., 2007] 13

18 Definition Computer-based visualization systems provide visual representations of datasets designed to help people carry out tasks more effectively 14

19 Why Visual? y y x 1 x y y x x 4 [F. J. Anscombe] 15

20 Definition Computer-based visualization systems provide visual representations of datasets designed to help people carry out tasks more effectively 16

21 Design Iteration 17

22 Definition Computer-based visualization systems provide visual representations of datasets designed to help people carry out tasks more effectively 18

23 Effectiveness [S. Hayward, 2015] 19

24 Visualization Tools Analysis Apps: Tableau, Excel, SAS Illustration Apps: Illustrator, Inkscape R Libraries: base, ggplot Python Modules: matplotlib, seaborn, bokeh, altair Lower-level Frameworks: D3, Processing Many, many more: Google "data visualization tools" 20

25 This Class Tableau Python modules: matplotlib, bokeh 21

26 Data Types Items - An item is an individual discrete entity - e.g. row in a table, node in a network Attributes - An attribute is some specific property that can be measured, observed, or logged - a.k.a. variable, (data) dimension, column in a table 22

27 Items & Attributes attribute Field item 22 23

28 Dataset Types Dataset Types Tables Networks Fields (Continuous) Geometry (Spatial) Attributes (columns) Grid of positions Items (rows) Cell containing value Link Node (item) Cell Attributes (columns) Position Multidimensional Table Trees Value in cell Value in cell [Munzner (ill. Maguire), 2014] 24

29 Attribute Types Attribute Types Categorical Ordered Ordinal Quantitative Ordering Direction Sequential Diverging Cyclic [Munzner (ill. Maguire), 2014] 25

30 Categorial, Ordinal, and Quantitative 1 = Quantitative 23 2 ordinal = Nominal 3 = Ordinal quantitative categorical 26

31 Categorial, Ordinal, and Quantitative 1 = Quantitative 24 2 ordinal = Nominal 3 = Ordinal quantitative categorical 27

32 Tableau Overview Grew out of research at Stanford University on how to explore multidimensional datasets & relational databases Tableau Desktop: standalone (free trial, student license) Tableau Public: cloud-based system (free) Tableau Vizable: mobile app Tableau's Introduction Videos 28

33 Tableau High-level GUI that connects to data, helps organize it, and provides intuitive routines for visualizing it plus customization Lots of possibilities Great for exploration 29

34 Tableau Example 30

35 Data In Tableau Categorical data = Dimension Quantitative data = Measures 31

36 matplotlib The workhorse of python visualization seaborn builds on top of matplotlib Many new kids on the block: bokeh, altair 32

37 matplotlib %matplotlib inline (show plots in the notebook!) Always create a figure first, then draw plots Lots of high-level plotting types (line plots, scatterplots, histograms) Lots of customizability 33

38 Shortcuts in pandas Connect directly to pandas data frames - df.plot pandas.dataframe.plot.html 34