How to Create a Gauge Chart

What is a Gauge Chart

Gauge charts are used to represent single numeric values. They will be displayed as 0..100% values from the whole.

We have five types of gauge charts, each derived from a chart type for multiple values. When the base chart type value returns one single row, we also automatically show it as a gauge value. For instance, a Doughnut chart displaying one single value will appear as a Doughnut Gauge. This is because it would make no sense and have no usage to show a shape painted totally in a single color.

Our gauge chart types are:

1. Pie Gauge – derived from and represented with a pie chart.
2. Doughnut Gauge – derived from and represented with a doughnut chart.
3. Solid Gauge – derived from and represented with a semi-doughnut chart.
4. Dot Matrix Gauge – derived from and represented with a dot matrix chart.
5. Waffle Gauge – derived from and represented with a waffle chart.

Steps to Create a Gauge Chart

Start Visual Xtractor or Data Xtractor. Connect to a database. Create or design a SQL query. Run the query and check the results.

1. Display and enable the Chart query builder.
2. Select one or more numeric data columns with one of the Gauge Charts – Pie Gauge, Doughnut Gauge, Solid Gauge, Dot Matrix Gauge or Waffle Gauge chart types.
3. Or return one data row for one of the Pie, Doughnut, Semi-Doughnut, Dot Matrix or Waffle chart types instead.
4. Select another optional textual column as Label, as value label and for the legend.

Gauge Chart Demo Queries

Look for Gauge-based ready-to-use generated queries under the Queries > Demo Queries > Charts folder. Click on the “add demo queries” command link, if not there.

We’ll show here just the Solid Gauge sample, as most of other gauge chart types are similar.

Generated demo queries must work for any database, with no restriction. They use constant values generated on-the-fly and your database SQL engine, but do not depend on data from your tables, and never alter your database in any way.

Multiple Split Gauge Demo Queries

Gauge charts are single-series and you cannot mix more than one on the same chart.

However, you may add Gauge chart selections for more than one data value, and they will appear split as multiple small charts. You may as well use the legend items to hide some of these charts.

Look for the ready-to-use Multiple Doughnut Gauges generated query under the Queries > Demo Queries > Charts > Multiple Charts folder. Click on the “add demo queries” command link, if not there.

Change the Doughnut Gauge selections with Solid Gauge.

Customize your Gauge Chart

1. Switch to the 3D view and/or change the drawing style.
2. Show doughnut gauges as thin rings, or solid gauges as thin arcs.
3. Change the marker shape of a dot matrix gauge.
4. Click on legend items to hide some of the multiple split charts.

Conclusion

• Creating Gauge Charts in Data Xtractor or Visual Xtractor is fast and easy: set your numeric data column as either a Pie Gauge, Doughnut Gauge, Solid Gauge, Dot Matrix Gauge or Waffle Gauge, and add an optional column as Label. Only the first row value will be considered and represented as a 0..100 percent of the whole surface.
• As an alternative, return one single numeric value for a Pie, Doughnut, Semi-Doughnut, Dot Matrix or Waffle chart. It will be displayed as a Gauge chart instead.
• Multiple Gauge columns are automatically split into small separated gauge charts.
• All builtin powerful features of these chart type are common to most other charts: filtering series through the legend items, interactivity, monochrome or grayscale colors, rich axis and data label selections etc.
• Switch to another builtin chart theme, or customize your own, for any possible color or other styles.