Posts tagged data visualization
ADF 12c – The Hierarchical Mystery Tour – Treemap, Sunburst, Treetable, Hierarchy Viewer and Thematic Map0
Hierarchical data is common phenomenon in the real world. Presenting such data to allow users to quickly grasp the composition of numbers, to compare quantities, to navigate through a data set and to have a pleasant experience with potentially dreary facts is quite valuable. ADF 12c (as well as previous releases) offer a wealth of components that help us present data in interesting, meaningful ways. For hierarchical data, components that come to mind include the Hierarchy Viewer, the Treemap and Sunburst components and if the data is of a geographical nature the Map components. Of course the tree and treetable and pivot table can be used to present such data as well.
This article demonstrates the use of a number of these components on population statistics for cities, countries, continents and regions. I hope you spot the hierarchical pattern in this list. This YouTube movie (4.20 minute, no sound) shows the components in actions. The resources section of this article makes the JDeveloper 12c (12.1.2) application available for download, with all the source code inside.
The recent JDeveloper/ADF 11gR1 Patch Set 6 release introduced the Sunburst component, one of the many data visualization components in ADF. Sunburst (sometimes called Rings Chart) provides an attractive and useful way to quickly learn about the hierarchical build of certain values. One well known example is the space usage on a storage device, such as on the Gnome desktop on Linux – see on the right.
The left side of the figure shows the directories on the file system and their relative and absolute size. The rings chart or sunburst makes it abundantly clear which directories contain the most data and which subdirectories inside are the big ones.
The ADF DVT Sunburst component allows us to create a similar representation of the build up of a values from their constituents and their constituents. A simple and not very exciting example is presented in this article: the salary distribution in table EMP – per department (level 1) and per employee (level 2). We will also compare this presentation as sunburst with the counterpart presentation using Treemap. The two are quite similar and can be used in similar circumstances, depending on whether the focus of using the data visualization More >
In a recent article (http://technology.amis.nl/2013/04/02/adf-dvt-using-the-tree-map-visualization-component-to-compare-relative-sizes-and-distributions/) I discussed the ADF DVT Treemap component. This component visualizes data in such a way that comparisons between data values for different records and categories can quickly be made. The size of areas is a measure for some numerical value. As an additional dimension, the color of the areas can be used to identify groups (all members of the group having the same color) or to visualize a second numerical value (color can range for example from dark red to rich green depending on the net revenue per record).
This article describes the situation where we want to use multiple Treemap instances lined up. Each Treemap instance represents a collection of records on one or possibly multiple levels. Each instance can be drilled down into independently. And each instance can represent a different data set, even though we want to compare these data sets. Using a PanelGridLayout, it is easy to position multiple instances in a row or a grid. Using the inline style to scale the width and height of the Treemap instances, we can set the relative More >
The tree map component is one of those data visualization components that can tell an entire story through a simple picture. But of course that picture is anything but simple. And it is not even just a picture: it supports various forms of interaction such as drill down and popup. I had seen the Tree Map for the first time in demonstrations by Oracle Product Management. It seemed okay, but nothing very spectacular. Now, after having tried out the component for myself as well as studying the documentation, I may have to revise my initial opinion: it is actually a pretty cool and powerful component.
The Tree Map is used to present data values in a way that makes comparison easy, using two dimensions: (relative) size and color. The TreeMap uses containers for nodes with sizes relative to the numerical value associated with the nodes. Each node can have details and the container is presented with enclosed areas for each of the details. The size of these areas is proportional again to the value associated with the child node. All areas can be colored automatically – to create a pretty picture – or can be colored according to rules we can specify in order to have the colors also convey More >
One recurring theme in my articles on ADF has been that end users usually do not care about data. They are interested in getting information that helps them answer questions, make decisions and take actions. Data may be the foundation, but information is to be derived from the data. One way therefore to create applications that are more valuable to our end users is by preprocessing data and turning the data into information – or even into answers, proposed decisions and actions. A powerful way of turning data into information is through data visualization. By presenting data in a format that converts it to readily interpretable information, we help our users a lot. Bar charts, line graphs and other traditional charting formats are one of way visualizing data. The DVT library in ADF Faces goes far beyond traditional charts. It provides components such as the Gantt Chart, the Hierarchy Viewer, the Tree Map, Gauge and the TimeLine that help visualize data in natural, informative and attractive ways. This articles discusses the TimeLine component – introduced in ADF 11gR1 PS6 (184.108.40.206) in the Spring of 2013.
The TimeLine visualizes events against a time axis. It is as simple as that. More >