Data visualization |

Target User / Scientist

Flow Maps in cartography can be defined as a mix of maps and Sankey diagrams, that show the movement of quantities from one location to another, such as the number of people travelling, the amount of goods being traded, or the number of packets in a network.
The width of the connections shows the quantity. Sometimes you flow maps with arrows to display the direction of the movement.
The most famous example of a flow map, is Minard’s map of Napoleon’s disastrous Russian campaign of 1812.

Flow Map

Comparing the distribution of data with a theoretical distribution from an ordinary histogram can be difficult because small frequencies are dominated by the larger frequencies and it is hard to perceive the pattern of differences between the histogram bars and the curve. Therefore John Tukey introduced the Hanging Rootogram in 1971 (also called Tukey’s Hanging Rootogram) in order to solve these problems. In this visualization the comparison is made easier by ‘hanging’ the observed results from the theoretical curve, so that the discrepancies are seen by comparison with the horizontal axis rather than a sloping curve. As in the rootogram, the vertical axis is scaled to the square-root of the frequencies so as to draw attention to discrepancies in the tails of the distribution.
It is a variation of the concept of histograms and Pareto charts by combining observed and predicted in a simple way where the line charts display that the data is continuously changing.

Hanging Rootogram

A topographic map is a detailed and accurate graphic representation of cultural and natural features on the ground. A topographic map is typically published as a map series, made up of two or more map sheets that combine to form the whole map. A contour line is a combination of two line segments that connect but do not intersect; these represent elevation on a topographic map.

Topographic Map

Similar to a regular square treemap, but convex polygons are used instead of rectangles e.g. a new hierarchical partition scheme, also called a polygonal partition, which uses convex polygons rather than just rectangles.
Treemaps display hierarchical (tree-structured) data as a set of nested polygons. Each branch of the tree is given a polygons, which is then tiled with smaller polygons representing sub-branches.
The use of Convex Treemaps compared to regular tree maps would be when you want to show grouping and realtions instead of the strict hierachical structure of a a normal treemap.

Convex treemap

It can be helpful to plot multiple datasets using a 3D form of bar chart or histogram. The multiple series 3D bar charts can be used for data sets with 3 variables (x,y, z)
Often the clarity of presentation can be reduced if the presentation is too crowded.

Multiple Series 3D Bar Charts

Cartograms distort the shape of geographic regions so that the area directly encodes a data variable. A common example is to redraw every country in the world sizing it proportionally to population or GDP. Can be done by circles, squares or distorted maps by manipulating the initial map.
Primarily used to visualize data related to countries, regions or states, for example votes in elections, population or income.


The opposite diagram can be used to display two set of opposites in a horizontal and vertical axis using Cartesian coordinates.
The data or items are displayed as a collection of points, each having the value of two variables determining the position on the horizontal axis and the value of the other variable determining the position on the vertical axis. In many ways it is similar to the scatter plot.
The values can be data driven, but it is often used for conceptual purposes by displaying opposites of an issue on a relative scale.

Opposite Diagram

A Sorted Stream Graph is area graph which is displaced around a central axis, resulting in a flowing, organic shape – but it is sorted instead of stacked.

Sorted Stream Graph

A Roof Shaped Matrix Diagram is one of six forms of Matrix Diagram. A Matrix Diagram shows the relationship between items. At each intersection, a relationship is either absent or present. It then gives information about the relationship, such as its strength, the roles played by various individuals or measurements. It can be shaped differently depending on how many groups must be compared. The other five differently shaped matrixes are: L, T, Y, X, C and R.

Matrix Diagram (Roof Shaped)

A hyperbolic tree defines a graph drawing method inspired by hyperbolic geometry.

Displaying hierarchical data as a tree suffers from visual clutter as the number of nodes per level can grow exponentially. For a simple binary tree, the maximum number of nodes at a level n is 2n, while the number of nodes for larger trees grows much more quickly. 
Drawing the tree as a node-link diagram thus requires exponential amounts of space to be displayed.

Hyperbolic Tree

The hive plot is a rational visualization method for drawing networks. Nodes are mapped to and positioned on radially distributed linear axes — this mapping is based on network structural properties. Edges are drawn as curved links. Simple and interpretable.
The purpose of the hive plot is to establish a new baseline for visualization of large networks — a method that is both general and tunable and useful as a starting point in visually exploring network structure.

Hive Plot

Parallel Sets are a new method for the visualization and interactive exploration of categorical data that shows data frequencies instead of the individual data points. The method is based on the axis layout of parallel coordinates, with boxes representing the categories and parallelograms between the axes showing the relations between categories.

Parallel Sets

A Sociogram is a graphic representation of social links that a person has. It is a graph drawing that plots the structure of interpersonal relations in a group situation. A sociogram can be drawn on the basis of many different criteria: Social relations, channels of influence, lines of communication etc.


The Polar Area chart is similar to a usual pie chart, except sectors are equal angles and differ rather in how far each sector extends from the center of the circle. The polar area diagram is used to plot cyclic phenomena (e.g., count of deaths by month).

Polar Area Chart

A streamgraph, or stream graph, is a type of stacked area graph which is displaced around a central axis, resulting in a flowing, organic shape. Streamgraphs were developed by Lee Byron.

Stream Graph

A phase diagram in physical chemistry, engineering, mineralogy, and materials science is a type of chart used to show conditions at which thermodynamically distinct phases can occur at equilibrium. Common components of a phase diagram are lines of equilibrium or phase boundaries, which refer to lines that mark conditions under which multiple phases can coexist at equilibrium. Phase transitions occur along lines of equilibrium.

Phase Diagram

A spiral heat map is a specific type of heat map designed for continuous comparable cycles like years or days. The spiral design makes it possible to compare the cycles, but keeping the continuous timeline along the spiral.

Spiral Heat Map

Network Visualisation (also called Network Graph) is often used to visualise complex relationships between a huge amount of elements. A network visualisation displays undirected and directed graph structures. This type of visualization illuminates relationships between entities. Entities are displayed as round nodes and lines show the relationships between them. The vivid display of network nodes can highlight non-trivial data discrepancies that may be otherwise be overlooked.

Network Visualisation

Polar chart displays multivariate data in the form of a two-dimensional chart of more than three variables represented on axes starting from the same point.

Polar Chart

Taylor diagrams (Taylor, 2001) provide a way of graphically summarizing how closely a pattern (or a set of patterns) matches observations. The similarity between two patterns is quantified in terms of their correlation, their centered root-mean-square difference and the amplitude of their variations (represented by their standard deviations). These diagrams are especially useful in evaluating multiple aspects of complex models or in gauging the relative skill of many different models (e.g., IPCC, 2001).

Taylor diagram

Radial Area Chart is a variation of Area Chart. An area chart displays graphically quantitive data. It is based on the line chart. The area between axis and line are commonly emphasized with colors, textures and hatchings. Whereas area charts are used to represent cumulated totals using numbers or percentages over time, Radial Area Chart can be also used to display categories instead.

Radial Area Chart

Radial Line Graph is a part of radial graphs that takes data and render it as collection of data points wrapped around a circle. It is also mapping a list of categories from the minimum to the maximum of the extent of the chart. Radial Line Graph is rendered using a collection of straight lines connecting data points.

Radial Line Graph

Isoline maps show a range of quantity. They show data as a third dimension on a map, making them good for mapping surface elevations or for weather data. Radar maps, temperature maps and rainfall maps are all isoline maps.

Isoline Map

A Contour Plot is a graphic representation of the relationships among three numeric variables in two dimensions. Two variables are for X and Y axes, and a third variable Z is for contour levels. The contour levels are plotted as curves; the area between curves can be color coded to indicate interpolated values.
The contour plot is an alternative to a 3-D surface plot.

Contour Plot

In addition to the Ternary Plot, you will also find the Ternary Contour Plot. These plots can be used for example to chart the response of an independent variable to changes in a mixture of three components.

Ternary Contour Plot

A range area chart is a variation of an area chart that lets you plot bands of data, such as Bollinger bands and weather patterns. Each point in the chart is specified by two y values.

Range Area Chart

A fan chart is a chart that joins a line graph for observed past data, and a range area chart for future predictions.
Predictions are shown as ranges for possible values of future data together with a line showing a central estimate or most likely value for the future outcomes. As predictions become increasingly uncertain the further into the future one goes, these forecast ranges spread out, creating distinctive wedge or “fan” shapes, hence the term. Alternative forms of the chart can also include uncertainty for past data, such as preliminary data that is subject to revision.
Read more about fan charts here

Fan Chart (Time Series)

A Waterfall Plot is a three-dimensional plot in which multiple curves of data, typically spectra, are displayed simultaneously. Typically the curves are staggered both across the screen and vertically, with ‘nearer’ curves masking the ones behind. The result is a series of “mountain” shapes that appear to be side by side. The waterfall plot is often used to show how two-dimensional information changes over time or some other variable such as rpm.
Not to be confused with the similarly named Waterfall Chart.

Waterfall Plot

A three-dimensional Stream Graph is the graph of a function f(x, y) of two variables, or the graph of a relationship g(x, y, z) among three variables.Provided that x, y, and z or f(x, y) are real numbers, the graph can be represented as a planar or curved surface in a three-dimensional Cartesian coordinate system. A three-dimensional graph is typically drawn on a two-dimensional page or screen using perspective methods, so that one of the dimensions appears to be coming out of the page.

Three-dimensional Stream Graph

The structural formula of a chemical compound is a graphic representation of the molecular structure, showing how the atoms are arranged. The chemical bonding within the molecule is also shown, either explicitly or implicitly. Unlike chemical formulas, which have a limited number of symbols and are capable of only limited descriptive power, structural formulas provide a complete geometric representation of the molecular structure

Molecule Diagram

Radial Convergences are used to visualize relationships between entities. Entities are displayed as round nodes and lines show the relationships between them. It is similar to a network visualization but it is arranged in strict circular layout.

Radial Convergences