Python for R Users

6Data Visualization

To dos: plot.ly, bokeh, Shiny, Googlevis

6.1 Concepts on Data Visualization

Data visualization is the presentation of data in a pictorial or graphical format to understand information more easily and quickly. Effective visualization helps users in analyzing and reasoning about data and evidence. It makes complex data more accessible, understandable, and usable. It is more than just impressive-looking graphs because it helps to understand data much better than a tabular nonvisual form would do. A good course to learn data visualization would be at https://www.coursera.org/learn/datavisualization

6.1.1 History of Data Visualization

William Playfair is credited with inventing many of the graphs associated with modern data visualization such as the line, area, and bar charts of economic data, pie chart, and circle graph.

The work of Charles Minard is said to have greatly influenced the field of data visualization. His famous chart, Napoleon’s march shows the death and decline of the French Grande Armée in the war against Russia. The graphic is notable for its representation in two dimensions of six types of data: the number of Napoleon’s troops, distance, temperature, latitude and longitude, direction of travel, and location relative to specific dates. It is thus an early example of an information graphic (Figure 6.1).

Figure 6.1 Minard’s graph for Napoleon’s ...