# Histogram charts

A histogram is similar in appearance to a bar chart, but instead of comparing categories
or looking for trends over time, each bar represents how data is distributed in a single category.
Each bar represents a continuous range of data or the number of frequencies for a specific data
point.

Histograms are useful for showing the distribution of a single scale variable. Data are binned and summarized by using a count or percentage statistic. A variation of a histogram is a frequency polygon, which is like a typical histogram except that the area graphic element is used instead of the bar graphic element.

Another variation of the histogram is the population pyramid. Its name is derived from its most common use: summarizing population data. When used with population data, it is split by gender to provide two back-to-back, horizontal histograms of age data. In countries with a young population, the shape of the resulting graph resembles a pyramid.

## Creating a histogram chart

- In the Chart Type section, click the Histogram
icon.
The canvas updates to display a histogram chart template.

- Select a scale variable as the X-axis variable.
Note: The statistic for a histogram is Histogram or Histogram Percent. These statistics bin the data and calculate a count for each bin.
- Click the Save visualization in the project control. Select Create a new asset or Append to existing asset. Provide a Visualization asset name, an optional description, and a chart name.
- Click Apply to save the visualization to the project. The new visualization asset is now available on the Assets tab.

## Options

- X-axis
- Lists variables that are available for the chart's X-axis.
- Split by
- Select a categorical variable that creates a table of charts, with a cell for each category in the Split by variable. Like grouping, split by variables essentially add more dimensions to your chart by displaying information for each variable category.
- Bin method
- Specify a bin method that is used to create the chart bars. Available option include Auto bin, By bin width, and By bin num.
- Show kde curve
- When enabled, the kernel density estimate curve is shown on the chart.
- Show distribution curve
- When enabled, the distribution fitting curve is shown on the chart.
- Distribution
- The drop-down list provides to the following distribution options.
- Auto fit distribution
- Automatically fits the distribution (the default setting).
- Beta
- Returns the value from a Beta distribution with specified shape parameters.
- Exponential
- Returns the value from an exponential distribution.
- Gamma
- Returns the value from the Gamma distribution, with the specified shape and scale parameters.
- Log-normal
- Returns the value from a log-normal distribution with specified parameters.
- Normal
- Returns the value from a normal distribution with specified mean and standard deviation.
- Triangular
- Returns the value from a triangular distribution with specified parameters.
- Uniform
- Returns the value from the uniform distribution between the minimum and maximum.
- Weibull
- Returns the value from a Weibull distribution with specified parameters.

- Bin width
- The slider controls the size of the interval that is used to split the data into groups.
- Primary title
- The chart title.
- Subtitle
- The chart subtitle.

- Footnote
- The chart footnote.
- XAxis label
- The x-axis label.
- YAxis label
- The y-axis label.