Pie graphs use ‘pie slices’ to show relative sizes of data. The data they display adds to 100% and they are an effective way to display the part to whole relationship.
Pie graphs are most effective when they do not include too many categories of data as they are designed to show proportions at a glance, facilitating easy understanding.
In this article
1. Pie graphs
One Variable
When one variable or axis is selected, in either the Down or Across drop zone, Harmoni displays a standard pie chart with pie slices. Create your table with one axis and from the Visualize menu, select the pie graph icon.
Two Variables
When two variables or axes are selected, creating a cross tab analysis, Harmoni displays the Down axis in the center of the pie chart and the Across axis around the outside of the pie graph. The center portion will add to 100% as will the outside portion of the pie graph and Harmoni automatically recalculates the correct percentages.
Important Features:
- When pie graphs display data, the segments always add to 100%
- The percentages displayed on the graph are share percentages
- In the analysis table, if the axis does not add to 100% or a selection of elements is made, Harmoni rebases the percentages in the Pie chart, so that they add to 100%
- Change the number of decimal places using the drop-down menu under the pie graph icon. Note that changing the decimal places in the analysis table does not transfer to the pie graph.
2. Display Settings
Down Drop Zone
Selecting a pie when an axis is in the Down drop zone will display the labels in a legend and a range of colors identify the segments.
Across Drop Zone
Selecting a pie graph when an axis is in the Across drop zone displays the labels next to the graph. A single hue with varying shades identifies the segments.
Table and Share Percentages
The purpose of a pie chart is to display the proportional share of each element with a total of 100%. If a chart is created from an axis that does not add to 100% or a subset of elements within the axis are selected, then share percentages that are displayed in the chart differ from the table percentages. Single response axes display the same percentages in the table and chart (as long as all elements are selected), while multiple response axes recalculate to show the share percentage.
To show the table percentages on a donut graph, visualize the graph, then from the modify menu, select the show/hide table result icon (R). Table percentages are displayed in brackets next to the share percentages, e.g. 17% (65%).
Graph Selected Elements
You may not need to show all the elements in a pie graph. By selecting only those required in your analysis table and using a pie graph, Harmoni automatically reproportions the percentages based on the selected elements
In the following example, Australia, Japan and China are selected in the table and graphed.
Rank
When creating the table for your pie graph, select the column or row to rank, and select rank from the modify menu. The segments are ordered from highest to lowest. Click rank again to reverse the order. Once you have ranked the data as required, choose your graph type from the visualize menu.
Redraw
You can group elements with smaller percentages together as ‘Others’ to remove the clutter on the graph. Pie graphs are more effective with a smaller number of segments.
Decimal Places
Change the number of decimal places showing in the share percentages by clicking the drop down menu below the pie graph icon. Type the number of decimals required and press enter.
Where to from here?
Learn more about visualizing in Harmoni: