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".
population, not for
avg(population). To work around this limitation, first save the calculated metric as derived data, and then use this field as a measure in a histogram. See Derived Data.
When you change the number of buckets (the default is 10), Arcadia Enterprise determines the data range and splits it equally among the buckets, groups the metric into these buckets, and plots vertical bars to represent it.
The following steps demonstrate how to create a new histogram visual on a dataset
World Life Expectancy [data source
World Life Expectancy[data source
samples.world_life_expectancy]; see Creating Visuals.
In the visuals menu, find and click histogram (row 4, column 5).
To show specific items, populate the shelves from the available fields (Dimensions, Measures, and so on) listed in the left navigation menu.
Under Measures, select
population and drag it over the Measures shelf on the main part of the screen. Drop to add it to the shelf.
Click Refresh Visual.
The default histogram visual appears, dividing the data into 10 buckets. As you can see, most the data is in the first bucket, and this visual is not very enlightening.
[Optional] On the Filters shelf, add several fields from Dimensions and Measures.
This enables you to dynamically control the data input, and discover the data at a more granular level.
For example, from Dimensions, drag
year onto the Filters shelf, and select the year 2010.
You can also add
un_region to the Filters shelf, and select Africa.
Click Refresh Visual, and note the new shape of the histogram.
Hovering the mouse over the histogram shows the data ranges and frequency for each bucket of the histogram.
Notice that the filtering options significantly reduced result set.
Click Edit next to the title of the visualization.
World Population - Histogram.
Above the left navigation bar, click Save.
The default number of histogram buckets is 10, but you can easily change this.
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.
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.
Note the appearance of the normalized histogram, where the vertical axis and the Tooltips report Frequency as a percentage.
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.
Note the appearance of the histogram when the buckets report cumulative values.