Numerical Range facets

Virtual numerical facets are used to organize search results in ranges.

Unlike category facets, the values created by a virtual numerical facet do not have a hierarchy. They are, however, attached to a "virtual root", which is a category path under which the virtual categories are created.

The computation is based on a virtual field expression, which allows you to categorize based on any calculation supported by the virtual expression syntax.

You then need to specify how you want to create these ranges.

This page discusses:

See Also
About facets
Create Facets

Create Ranges Automatically

When facet ranges are created automatically, they generate ranges across the results of the query. However, this feature can be costly in terms of memory consumption.

The following range-generation policies are available:

  • Linear

  • Geometric

Linear Range Policy

A linear range policy defines ranges so each range includes a similar number of documents. The Max number of ranges option defines the number of ranges to generate and the parameter policy defines which policy must be applied.

For example, for these search results:

  • 10 documents that each contain 1

  • 9 documents that each contain 2,3,4,..,10

With the following configuration:

  • Range generation policy: linear

  • Max. number of ranges: 2

Displays the dynamic range facets as follows:

Top/
        dynamic2/      19
         [1;1]    10
         [2;10]   9

Geometric Range Policy

A geometric range policy accepts the same parameters as linear, except that each range contains twice as many documents as the range that follows.

Create Ranges That Are the Same Size

In this variant, a fixed range size is given, and a facet value is created for multiples of this range. For example, create a facet on price with a range size of 100 creates the following facet values:

  • 0-100

  • 101-200

  • 201-300

Create Ranges Manually

In this variant, you can manually specify the ranges. Each range receives a title, which is the value of the category.

Range boundaries are inclusive, therefore, if you have 2 ranges [0;1] and [1;2], 1 is in both ranges.

For example, we can define an explicit range facet on the expression:

#now() - last_modified_date, with the following ranges:

min=0, max=86400*7 --> title = "Modified last week"

min=86400*7, max=86400*31 --> title = "Modified last 30 days"