# Histograms

CDP Data Visualization enables you to create *Histogram* visuals.

Histogram visuals enable quick visual analysis of the distribution of numerical data. It is an estimate of the frequency distribution of a continuous quantitative variable, accomplished by splitting it into consecutive, non-overlapping intervals, referred to as "buckets".

When you change the number of buckets (the default is 10), CDP Data Visualization determines the data range and splits it equally among the buckets, groups the metric into these buckets, and plots vertical bars to represent it.

Histograms support both normalized and cumulative forms, and may be used in a trellis formation.

The following steps demonstrate how to create a new histogram visual on a dataset
`World Life Expectancy`

[data source
`samples.world_life_expectancy`

].

For an overview of shelves that specify this visual, see Shelves for histograms.

**Specifying the Bucket Count**

The default number of histogram buckets is 10, but you can easily change this.

Follow the instructions in Customizing basic settings and Changing the bucket count to double the number of buckets in the histogram.

Note the appearance of the histogram when the number of buckets doubles, and the range of values covered by each bucket is therefore reduced by half.

**Normalizing the Histogram**

The default vertical axis of a histogram represents the count of values that map to a particular bucket. To report the histogram as a percentage of a whole, the histogram count is normalized to add up to 1, and then the bars represent the proportionate frequency.

Follow the instructions in Customizing basic settings and Showing normalized histograms to double the number of buckets in the histogram.

Note the appearance of the normalized histogram, where the vertical axis and the Tooltips report Frequency as a percentage.

**Cumulative**

By default, the histogram reports each bucket individually. The cumulative option adds each bucket's count or frequency to the running total, so that the right-most bucket reports the total count or 1 (100%), depending on whether the normalized histogram option is active.

Follow the instructions in Customizing basic settings and Showing cumulative histograms to double the number of buckets in the histogram.

Note the appearance of the histogram when the buckets report cumulative values.