Working with Histograms

About Histograms

A histogram displays the distribution of values for a single measure. A series of bars represents the number of observations in the measure that match a specific value or value range. The bar height can represent either the exact number of observations or the percentage of all observations for each value range.

Note: If you use the default number of bins, then the minimum and maximum values on the histogram axis might not match the actual extent of your data values. If you specify the number of histogram bins, then the histogram axis matches your data values exactly.

Data Roles for a Histogram

The basic data role for a histogram is a measure. You can assign only one measure to a histogram.

Specify Properties for a Histogram

On the Properties tab, you can specify the following options:

Name

specifies the name of the visualization.

Title

specifies the title that appears above the graph.

Note: The Title option is disabled if you select Generate graph title.

Generate graph title

specifies that the graph title is generated automatically based on the data items in the visualization.

Show grid lines

displays grid lines for each tick on the response axis.

Bar direction

specifies whether the bars are vertical or horizontal.

Frequency

specifies whether the frequency is displayed as a count (Count) or as a percentage (Percent).

Note: The frequency values are based on the data that is shown in the visualization (after filters and other data selections have been applied).

Use default bin count

specifies whether to use the default number of bins (value ranges) for the histogram. The default number of bins is determined by the number of data values in your histogram.

Bin count

specifies the number of bins (value ranges) for the histogram.

Reference Lines

adds reference lines to the visualization. To create a reference line, click Create new reference line

, and then specify the parameters for the line in the New Reference Line window.

The name of each reference line appears below the Reference Lines option. You can edit or delete your reference lines by using the icons next to each name.