Khairi Reda | redak@iu.edu School of Informa5cs & Compu5ng, IUPUI
I590 Interactive Visual Analytics Week 5 | Sep 21, 2016 Data - - PowerPoint PPT Presentation
I590 Interactive Visual Analytics Week 5 | Sep 21, 2016 Data - - PowerPoint PPT Presentation
I590 Interactive Visual Analytics Week 5 | Sep 21, 2016 Data Abstraction Visual Encoding Khairi Reda | redak@iu.edu School of Informa5cs & Compu5ng, IUPUI Project 1 Due Tuesday, Sep 27 at 8:59 PM Turn in as online web pages: Video with
Project 1
Due Tuesday, Sep 27 at 8:59 PM Turn in as online web pages:
Interac>ve, live visualiza>on Design Document Video with narra>on
Last 2 weeks
- C. Ware
Visual Thinking for Design
Wandell, “Foundations of Vision”
Cones, Rods, Color vision
HyperPhysics, Georgia State University
Simultaneous contrast
Via Colin Ware
Wong 2010 Via Miriah Meyer
Simultaneous contrast
POPOUT
Visual percep>on Our visual system sees differences, not absolute values, and is aGracted to edges. We can easily see objects that are different in color and shape, or that are in mo5on (popouts) Use color and shape sparingly to make the important informa5on pop out
Last 2 weeks
This week
- Data abstrac>on
- Datasets: Tables, Networks, Fields, Geometry.
- Variable types: Categorical, Ordinal, and
Quan5ta5ve variables
- Visual encoding
- Marks and channels
- Perceptual accuracy of channels
Data abstraction
type vs. seman>cs
Transla5on of domain-specific terms into words that are as generic as possible
Terminology
Dataset Type
collections of units
Data Type
fundamental units
Data Types
- Items: are individual units of data. For example: rows in a table, points
- n a 5meline, nodes, …
- AKribute: a property rela5ng to items, links, or posi5ons
- Link: linkage between (typically) two items
- Posi>on: designa5on of a point or a sub-space in a larger spa5al context
- Grids: par55oning of space into typically uniform cells
Dataset Types
Via Miriah Meyer
Flat Tables
Key: Order ID
Multidimensional Tables
Alex Lex
Visualizing Tables
Example Parallel Coordinates
Dataset Types
Network / Graph items = people links = friendship
Network / Graph
Matrix
Mike Bostock
Node-link diagram
Wikipedia
Hierarchy/ Tree
items = states links = winning paths
http://orig00.deviantart.net/7534/f/2008/105/2/0/2027d31d532a91b7324f30af187e0819.png
Hierarchy/ Tree
items = species links = evolu5onary ancestry
http://orig00.deviantart.net/7534/f/2008/105/2/0/2027d31d532a91b7324f30af187e0819.png
items = zip codes links = containment
Hierarchy/ Tree
Dataset Types
Grid
position population density temperature attributes
Fields
Scalar fields
aKribute = one value examples: temperature, eleva5on
Vector fields
aKribute = vector (direc>on) wind map
Scalar + Vector fields
Fields
Fields
Scalar fields
aKribute = one (real) value examples: one MRI scan slice (5ssue density)
Based on a slide by Miriah Meyer
3D Fields
Based on a slide by Miriah Meyer
grid = MRI scan slices aGributes = 5ssue density
3D Fields
Visualizing 3D Fields
http://www.fovia.com/gallery/medical/mg_bs.jpg
http://www.dirkreiners.com/images/Research/tooth_tf.jpg
Volume Rendering
tissue density
- pacity
Grid Types
Slide by Alex Lex Wikipedia
Uniform Grids
Geometry & topology can be computed
Rec>linear Grid
Nonuniform sampling
Structured Grid Unstructured Grid
More flexibility, store posi5on and connec5on
Dataset Types
Geometry
World Atlas
Geometry
http://farbackoutdoors.com/1593-2/
Geometry
Dataset Types
Sets
Clusters
Dynamic (5me varying) clusters Sta5c clusters
Lists
Baseball salary vs. performance Ben Fry
LineUp
Attribute/Variable Types
✦Categorical (Nominal, Qualita>ve)
A finite set of categories No implicit ordering between categories
✦Ordered
- Ordinal
Implicit ordering between categories/levels, but no clear magnitude difference. Can compare and determine greater/less than
- Quan>ta>ve
Meaningful magnitude Can do arithme5c
Quan>ta>ve Data
Interval vs. Ordinal
✦ Interval
- Zero does not indicate an absence of detectable measurement
- We can determine distance between measurement, but not propor5ons
- Example: temperature, dates
✦ Ra>o
- The posi5on of zero indicates there is nothing of the measured en5ty
- Can determine ra5o and propor5ons
- Example: weight, age
Derived Data
f(x) + g(x)
Quiz
What aGribute/variable type (Categorical, Ordinal, Interval, or Ra5o) best fit the following measurements?
- Speed
- Facebook reac5ons (Like, Angry, Sad, etc…)
- Car configura5ons (Compact, Mid-Sedan, SUV)
- Product Name
- IQ scores
- College Majors
- 50-meter race 5me
Based on a slide by Alex Lex
Another way to think about Ordered aKributes
- Sequen5al
- Diverging
- Cyclic
temperature eleva5on (above/ below sea level) 5me
Colormap
categorical vs.
- rdered
sequential vs. diverging discrete vs. continuous
Match colormap to data type & task
Color design tools
Helpful to match variable/aGribute type to colormap