geo.geohash — factual/geo 3.0.1

Working with geohashes.

bbox clj

(bbox geohash)

bbox-geom clj

(bbox-geom geohash)

character-precision clj

(character-precision geohash)

concentric-square-rings clj

(concentric-square-rings origin)

(concentric-square-rings origin n)

Given a single geohash, returns a lazy sequence of concentric square rings of geohashes around it. The first element is [hash], the second element is [northern-neighbor, northwest-neighbor, west-neighbor, ...], the third element is the list of all geohashes around those, and so on.

degrees-precision-lat-cache clj

degrees-precision-long-cache clj

eastern-neighbor clj

(eastern-neighbor h)

geohash clj

(geohash string)

(geohash point precision)

(geohash lat long precision)

Creates a geohash from a string, or at the given point with the given bit precision.

geohash-center clj

(geohash-center geohash)

Returns the center point of a geohash.

geohash-error clj

(geohash-error geohash)

Returns the error (i.e. the distance in meters between opposite corners) of the given geohash.

geohash-max-error clj

(geohash-max-error bits)

Returns the maximum error (i.e. the distance between opposite corners of the geohash bounding box) for a given number of geohash bits. Geohashes are least precise at the equator.

geohash-midline-area clj

(geohash-midline-area geohash)

An estimate of a geohash's area, in square meters, based on its midline dimensions.

geohash-midline-dimensions clj

(geohash-midline-dimensions geohash)

Returns a vector of [lat-extent long-extent], where lat-extent is the length of the geohash through the midpoint of top and bottom, and long-extent is the length of the geohash through the midpoint of left and right sides. All figures in meters.

geohashes-intersecting clj

(geohashes-intersecting shape desired-level)

(geohashes-intersecting shape min-level max-level)

geohashes-near clj

(geohashes-near point radius precision)

Returns a list of geohashes of the given precision within radius meters of the given point.

least-upper-bound-index clj

(least-upper-bound-index numbers target)

Given a sequence of numbers in descending order, finds the index of the largest number which is just greater than the target.

neighbors clj

(neighbors h)

northern-neighbor clj

(northern-neighbor h)

shape->precision clj

(shape->precision shape)

Estimates the precision which generates geohash regions on the scale of the given shape.

significant-bits clj

(significant-bits geohash)

southern-neighbor clj

(southern-neighbor h)

square-ring clj

(square-ring origin n)

Given a geohash at the northeast corner of a square (n-2) geohashes on a side, returns a list of geohashes in a path around the square, such that the first entry in the list is the northeast corner of a square (n) geohashes on a side.

O is the origin argument F is the first hash in the returned sequence L is the last hash in the returned sequence E represents the last and first in the sequence

n=1 3 5 7 +----LF +--LF | O| +LF | O| | | E |O| | | | | +-+ | | | | +---+ | | +-----+

If n is one, returns [origin].

This algorithm is undefined at the poles.

string clj

(string geohash)

Returns the base32 encoded string value of a geohash.

subdivide clj

(subdivide geohash)

(subdivide geohash precision)

Given a geohash, returns all geohashes inside it, of a given precision.

subdivide-levels clj

(subdivide-levels geohash min-precision max-precision)

Given a geohash and a range of levels, return all geohashes inside the given geohash at all the levels in the range

western-neighbor clj

(western-neighbor h)