[[pie-chart]]
== Pie Charts

The slice size of a pie chart is determined by the _metrics_ aggregation. The following aggregations are available for
this axis:

*Count*:: The {ref}/search-aggregations-metrics-valuecount-aggregation.html[_count_] aggregation returns a raw count of
the elements in the selected index pattern.
*Sum*:: The {ref}/search-aggregations-metrics-sum-aggregation.html[_sum_] aggregation returns the total sum of a numeric
field. Select a field from the drop-down.
*Unique Count*:: The {ref}/search-aggregations-metrics-cardinality-aggregation.html[_cardinality_] aggregation returns
the number of unique values in a field. Select a field from the drop-down.

Enter a string in the *Custom Label* field to change the display label.

The _buckets_ aggregations determine what information is being retrieved from your data set.

Before you choose a buckets aggregation, specify if you are splitting slices within a single chart or splitting into
multiple charts. A multiple chart split must run before any other aggregations. When you split a chart, you can change
if the splits are displayed in a row or a column by clicking the *Rows | Columns* selector.

You can specify any of the following bucket aggregations for your pie chart:

*Date Histogram*:: A {ref}/search-aggregations-bucket-datehistogram-aggregation.html[_date histogram_] is built from a
numeric field and organized by date. You can specify a time frame for the intervals in seconds, minutes, hours, days,
weeks, months, or years. You can also specify a custom interval frame by selecting *Custom* as the interval and
specifying a number and a time unit in the text field. Custom interval time units are *s* for seconds, *m* for minutes,
*h* for hours, *d* for days, *w* for weeks, and *y* for years. Different units support different levels of precision,
down to one second. Intervals are labeled at the start of the interval, using the date-key returned by Elasticsearch. 
For example, the tooltip for a monthly interval will show the first day of the month.
*Histogram*:: A standard {ref}/search-aggregations-bucket-histogram-aggregation.html[_histogram_] is built from a
numeric field. Specify an integer interval for this field. Select the *Show empty buckets* checkbox to include empty
intervals in the histogram.
*Range*:: With a {ref}/search-aggregations-bucket-range-aggregation.html[_range_] aggregation, you can specify ranges
of values for a numeric field. Click *Add Range* to add a set of range endpoints. Click the red *(x)* symbol to remove
a range.
*Date Range*:: A {ref}/search-aggregations-bucket-daterange-aggregation.html[_date range_] aggregation reports values
that are within a range of dates that you specify. You can specify the ranges for the dates using
{ref}/common-options.html#date-math[_date math_] expressions. Click *Add Range* to add a set of range endpoints.
Click the red *(/)* symbol to remove a range.
*IPv4 Range*:: The {ref}/search-aggregations-bucket-iprange-aggregation.html[_IPv4 range_] aggregation enables you to
specify ranges of IPv4 addresses. Click *Add Range* to add a set of range endpoints. Click the red *(/)* symbol to
remove a range.
*Terms*:: A {ref}/search-aggregations-bucket-terms-aggregation.html[_terms_] aggregation enables you to specify the top
or bottom _n_ elements of a  given field to display, ordered by count or a custom metric.
*Filters*:: You can specify a set of {ref}/search-aggregations-bucket-filters-aggregation.html[_filters_] for the data.
You can specify a filter as a query string or in JSON format, just as in the Discover search bar. Click *Add Filter* to
add another filter. Click the image:images/labelbutton.png[] *label* button to open the label field, where you can type
in a name to display on the visualization.
*Significant Terms*:: Displays the results of the experimental
{ref}/search-aggregations-bucket-significantterms-aggregation.html[_significant terms_] aggregation. The value of the
*Size* parameter defines the number of entries this aggregation returns.

After defining an initial bucket aggregation, you can define sub-buckets to refine the visualization. Click *+ Add
sub-buckets* to define a sub-aggregation, then choose *Split Slices* to select a sub-bucket from the list of
types.

When multiple aggregations are defined on a chart's axis, you can use the up or down arrows to the right of the
aggregation's type to change the aggregation's priority.

include::color-picker.asciidoc[]

Enter a string in the *Custom Label* field to change the display label.

You can click the *Advanced* link to display more customization options for your metrics or bucket aggregation:

*Exclude Pattern*:: Specify a pattern in this field to exclude from the results.
*Include Pattern*:: Specify a pattern in this field to include in the results.
*JSON Input*:: A text field where you can add specific JSON-formatted properties to merge with the aggregation
definition, as in the following example:

[source,shell]
{ "script" : "doc['grade'].value * 1.2" }

NOTE: In Elasticsearch releases 1.4.3 and later, this functionality requires you to enable
{ref}/modules-scripting.html[dynamic Groovy scripting].

The availability of these options varies depending on the aggregation you choose.

Select the *Options* tab to change the following aspects of the table:

*Donut*:: Display the chart as a sliced ring instead of a sliced pie.
*Show Tooltip*:: Check this box to enable the display of tooltips.

After changing options, click the *Apply changes* button to update your visualization, or the grey *Discard
changes* button to keep your visualization in its current state.
