Table of Contents
What is a Histogram Chart
It may look like a vertical Bar Chart, but histogram values are calculated internally in a much different way. You may pump some numeric data into a Column Chart, and show no gaps between the bars, but this is still not a Histogram.
Histogram Charts calculate and render the statistical distribution of your values over a number of intervals, called bins or buckets. We use by default 20 buckets, but you may change this number and get a slightly different view.
Steps to Create a Histogram Chart
Start Visual Xtractor or Data Xtractor. Connect to a database. Create or design a SQL query. Run the query and check the results.
- Display and enable the Chart query builder.
- Select one numeric column as Point Charts – Histogram.
Histogram Chart Demo Query
Look for the ready-to-use Histogram Chart generated chart query under the Queries > Demo Queries > Charts > Cartesian Charts folder. Click on the “add demo queries” command link, to make sure it’s there.
The demo chart looks more complex, as it is a mixed chart, that we will present as final custom view later on. But is is very easy to start from scratch: just pass all values from any numeric data column you may have to a Histogram selection.
Play with different values for the selected bins/buckets, which will translate into the total number of bars you want to see on the chart.
Customize your Histogram Chart
- Change the drawing style of your bars.
- Select a semi-transparent Density Plot for the exact same column values, to get a similar chart mixed with the initial Histogram.
- Present yet another view with a Scatter Bar on top, on the exact same values again.
- Switch to 3D eventually, for a nice interesting view.
- Creating a Histogram Chart in Data Xtractor or Visual Xtractor is fast and immediate: just pass some numeric column values to a Histogram chart type selection, nothing more.
- Show a semi-transparent Density Plot on the background, on the same column values.
- Or add a horizontal Scatter Bar on top, on the same values, for yet another view.
- 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.