Apache Solr Reference Guide Covering Apache Solr 6.0

interface being developed allows an explicit resolution increase/decrease feature then subsequent requests can
specify the gridLevel explicitly.
The minX, maxX, minY, maxY reports the region where the counts are. This is the minimally enclosing bounding
rectangle of the input geom at the target grid level. This may wrap the dateline. The columns and rows values
are how many columns and rows that the output rectangle is to be divided by evenly. Note: Don't divide an
on-screen projected map rectangle evenly to plot these rectangles/points since the cell data is in the coordinate
space of decimal degrees if geo=true or whatever units were given if geo=false. This could be arranged to be
the same as an on-screen map but won't necessarily be.
The counts_ints2D key has a 2D array of integers. The initial outer level is in row order (top-down), then the
inner arrays are the columns (left-right). If any array would be all zeros, a null is returned instead for efficiency
reasons. The entire value is null if there is no matching spatial data.
If format=png then the output key is counts_png. It's a base-64 encoded string of a 4-byte PNG. The PNG
logically holds exactly the same data that the ints2D format does. Note that the alpha channel byte is flipped to
make it easier to view the PNG for diagnostic purposes, since otherwise counts would have to exceed 2^24
before it becomes non-opague. Thus counts greater than this value will become opaque.
BBoxField
The BBoxField field type indexes a single rectangle (bounding box) per document field and supports searching
via a bounding box. It supports most spatial search predicates, it has enhanced relevancy modes based on the
overlap or area between the search rectangle and the indexed rectangle. It's particularly useful for its relevancy
modes. To configure it in the schema, use a configuration like this:
BBoxField is actually based off of 4 instances of another field type referred to by numberType. It also uses a
boolean to flag a dateline cross. Assuming you want to use the relevancy feature, docValues is required. Some
of the attributes are in common with the RPT field like geo, units, worldBounds, and spatialContextFactory
because they share some of the same spatial infrastructure.
To index a box, add a field value to a bbox field that's a string in the WKT/CQL ENVELOPE syntax. Example: EN
VELOPE(-10, 20, 15, 10) which is minX, maxX, maxY, minY order. The parameter ordering is unintuitive
but that's what the spec calls for.
To search, you can use the {!bbox} query parser, or the range syntax e.g. [10,-10 TO 15,20] , or the
ENVELOPE syntax wrapped in parenthesis with a leading search predicate. The latter is the only way to choose
a predicate other than Intersects. For example:
&q={!field f=bbox}Contains(ENVELOPE(-10, 20, 15, 10))
Now to sort the results by one of the relevancy modes, use it like this:
&q={!field f=bbox score=overlapRatio}Intersects(ENVELOPE(-10, 20, 15, 10))
The score local-param can be one of overlapRatio, area, and area2D. area scores by the document area
using surface-of-a-sphere (assuming geo=true) math, area2D uses simple width * height. overlapRatio
computes a [0-1] ranged score based on how much overlap exists relative to the document's area and the query
area. The javadocs of BBoxOverlapRatioValueSource have more info on the formula, if you're really curious.
There is an additional parameter queryTargetProportion that allows you to weight the query side of the formula
to the index (target) side of the formula. You can also use &debug=results to see useful score computation
info.
Apache Solr Reference Guide 6.0
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