Data Visualization

Authors:Peter Yochev, Danitsa Andreeva, Plamena Radneva, Ivan Chervenkov

Software Technology and DesignThe Paisii Hilendarski University of Plovdiv

Plovdiv, January 30, 2014

Content● Patterns Over Time

● Proportions

● Relationships

● Differences

Patterns Over Time

Patterns Over TimeOne of the first knowngraphics: Planetary movementchart, 10th century

Patterns Over TimeThe first bar chart,1786, William Playfair

Patterns Over TimeJohn Snow’s map of Cholera outbreaks in the London epidemic of 1854

Patterns Over Time

Charles Minard’s 1869 chart showing the number of men in Napoleon’s 1812 infamous Russian campaign army

Proportions

There are many options to visualizedata out there, but it may be hardsimply to find the perfect chart orthe perfect graph that can suityour data best. To make your decision clearer and easier there are lots of proportions available.

Using Different ways to visualize data with proportions

Graphs and charts:● Pie chart● Donut chart● Stacked area chart● Treemap● Voronoi diagram

Pie chartPie chart:● Circular chart divided into sectors● Illustrates numerical proportions● Most effective when limited

components are used● Most effective when limited

components are used

Donut chartDonut chart:● Functionally similar to pie charts● Display data in rigs, where each

ring represents data series● Can support multiple statistics at

once with its blank center● Total 100% when percentage is

used

Stacked area chartStacked area chart:● Graphical display of

quantitive data based on a line chart

● Uses axis and lines● The area between axis

and lines are colored and textured to emphasize changes

● Commonly used to represent trends over time

TreemapTreemap:● Hierarchical displayed data as

a set of nested rectangles● Uses branches-rectangles

which tile with smaller sub-branches

● Can legibly represent lots of items because of their simple construction

Voronoi diagramVoronoi diagram:● Visualize magnitude using

convex polygons● Uses robust algorithms to

sidestep problems when restricted to rectangles

● Can be found also in technology, science and even in art

Relationships

… Or how to visualize data relationships effectively.

The ‘Foundation’: Entity-Relationship (ER) diagram> Can be considered as the‘base’ of all the charts which display data relationships.

Figure 1: ER Diagram legend Figure 2: Elaborated (classic) ER diagram (i.e, contains both entities and properties)

Figure 3: Simplified ER Diagram (i.e, displays relationships only between entities)

The ‘Foundation’: Entity-Relationship (ER) diagram

The ‘Classic’: Scatter Plot chart

Figure 4: Simple Scatter Plot chart showing how twovariables/entities correlate

Figure 4: Bubble chart - can be considered as a variationof the Scatter Plot chart.

Hierarchy chart

Figure 5: Example of a Hierarchy chart Figure 6: Same idea, different look

Circle/Radial chart

Figure 7: Radial Cycle chart: Shows the relationship to a central idea and also how the information in the outer ring contributes to the main idea.

Figure 8: Stacked Venn chart: Best used for visualizing overlapping relationships.

DifferencesIn this lesson I will compare a few charts, which will show you the main

difference between them.

The first chart is called“apt” chart, which is an addition of the column charts.

Differences

The apt chart:● has small number of categories● can use shades of a single color● easiest way to show all bars belong

to same data type

Differences

The next one is the bar chart.

Differences

The bar chart:● more than 8 but less than 15 categories● more space for large names● arranged from lowest to highest● makes the understanding of the data easier● connects shape of value faster

Differences

The Line chart:● when you have a lot of numbers

of data points● doesn’t show minimum and

maximum● shows the rate of change of a

population● best fits for showing trend-based

visualization● has only 1 value axis● shows the population with

negative spikes,because of famines or some infections.

Differences

Sourceshttp://www.dundas.com/blog-post/a-brief-history-of-data-visualization/http://www.lynda.com/Processing-tutorials/Overview-data-visualization/97578/113145-4.htmlhttp://www.sas.com/offices/NA/canada/downloads/IT-World2013/Data-Visualization-Techniques.pdfhttp://flowingdata.com/2009/11/25/9-ways-to-visualize-proportions-a-guide/http://www.slideshare.net/idigdata/data-visualization-best-practices-2013http://xataface.com/documentation/tutorial/getting_started/first_applicationhttp://creately.com/blog/diagrams/er-diagrams-tutorial/http://book.flowingdata.com/downloads.htmlhttp://0.tqn.com/d/spreadsheets/1/0/z/3/-/-/column_chart6.gifhttp://upload.wikimedia.org/wikibooks/en/2/20/BarChartExampleHorizontal.PNGhttp://www.tutorial9.net/tutorials/web-tutorials/selecting-the-right-chart-type-for-your-data/#1

Any questions

Thank you for your attention