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Your IP : 3.142.135.247
/*
* Copyright 2023 Bytes & Brains
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
-- complain if script is sourced in psql, rather than via CREATE EXTENSION
\echo Use "ALTER EXTENSION h3_postgis UPDATE TO '4.1.1'" to load this file. \quit
-- raster
CREATE OR REPLACE FUNCTION
h3_cell_to_boundary_wkb(cell h3index) RETURNS bytea
AS 'h3' LANGUAGE C IMMUTABLE STRICT PARALLEL SAFE; COMMENT ON FUNCTION
h3_cell_to_boundary_wkb(h3index)
IS 'Finds the boundary of the index, converts to EWKB.
Splits polygons when crossing 180th meridian.
This function has to return WKB since Postgres does not provide multipolygon type.';
CREATE OR REPLACE FUNCTION
h3_cells_to_multi_polygon_wkb(h3index[]) RETURNS bytea
AS 'h3' LANGUAGE C IMMUTABLE STRICT PARALLEL SAFE; COMMENT ON FUNCTION
h3_cells_to_multi_polygon_wkb(h3index[])
IS 'Create a LinkedGeoPolygon describing the outline(s) of a set of hexagons, converts to EWKB.
Splits polygons when crossing 180th meridian.';
-- Raster processing
CREATE OR REPLACE FUNCTION __h3_raster_band_nodata(
rast raster,
nband integer)
RETURNS double precision
AS $$
SELECT coalesce(
ST_BandNoDataValue(rast, nband),
ST_MinPossibleValue(ST_BandPixelType(rast, nband)));
$$ LANGUAGE SQL IMMUTABLE PARALLEL SAFE;
CREATE OR REPLACE FUNCTION __h3_raster_to_polygon(
rast raster,
nband integer)
RETURNS geometry
AS $$
SELECT ST_MinConvexHull(rast, nband);
$$ LANGUAGE SQL IMMUTABLE PARALLEL SAFE;
CREATE OR REPLACE FUNCTION __h3_raster_polygon_pixel_area(
rast raster,
poly geometry)
RETURNS double precision
AS $$
SELECT ST_Area(
ST_Transform(
ST_PixelAsPolygon(
rast,
ST_WorldToRasterCoordX(rast, c),
ST_WorldToRasterCoordY(rast, c)),
4326)::geography)
FROM ST_Centroid(poly) AS c
$$ LANGUAGE SQL IMMUTABLE PARALLEL SAFE;
CREATE OR REPLACE FUNCTION __h3_raster_polygon_centroid_cell(
poly geometry,
resolution integer)
RETURNS h3index
AS $$
DECLARE
cell h3index := h3_lat_lng_to_cell(ST_Transform(ST_Centroid(poly), 4326), resolution);
BEGIN
IF h3_is_pentagon(cell) THEN
SELECT h3 INTO cell FROM h3_grid_disk(cell) AS h3 WHERE h3 != cell LIMIT 1;
END IF;
RETURN cell;
END;
$$ LANGUAGE plpgsql IMMUTABLE STRICT PARALLEL SAFE;
CREATE OR REPLACE FUNCTION __h3_raster_polygon_centroid_cell_area(
poly geometry,
resolution integer)
RETURNS double precision
AS $$
SELECT ST_Area(
h3_cell_to_boundary_geography(
__h3_raster_polygon_centroid_cell(poly, resolution)));
$$ LANGUAGE SQL IMMUTABLE PARALLEL SAFE;
CREATE OR REPLACE FUNCTION __h3_raster_polygon_to_cells(
rast raster,
poly geometry,
resolution integer,
buffer double precision)
RETURNS SETOF h3index
AS $$
DECLARE
buffered geometry := poly;
BEGIN
IF ST_SRID(rast) != 4326 THEN
buffered := ST_Transform(
ST_Buffer(
poly,
greatest(ST_PixelWidth(rast), ST_PixelHeight(rast)),
'join=mitre'),
4326);
END IF;
IF buffer > 0.0 THEN
RETURN QUERY
SELECT h3_polygon_to_cells(
ST_Buffer(
buffered::geography,
buffer,
'join=mitre'),
resolution);
ELSE
RETURN QUERY
SELECT h3_polygon_to_cells(buffered, resolution);
END IF;
END
$$ LANGUAGE plpgsql IMMUTABLE STRICT PARALLEL SAFE;
CREATE OR REPLACE FUNCTION __h3_raster_polygon_to_cell_boundaries_intersects(
rast raster,
poly geometry,
resolution integer)
RETURNS TABLE (h3 h3index, geom geometry)
AS $$
SELECT h3, geom
FROM
__h3_raster_polygon_to_cells(
rast,
poly,
resolution,
h3_get_hexagon_edge_length_avg(resolution, 'm') * 1.3
) AS h3,
ST_Transform(h3_cell_to_boundary_geometry(h3), ST_SRID(rast)) AS geom
WHERE ST_Intersects(geom, poly);
$$ LANGUAGE SQL IMMUTABLE PARALLEL SAFE;
CREATE OR REPLACE FUNCTION __h3_raster_polygon_to_cell_coords_centroid(
rast raster,
poly geometry,
resolution integer)
RETURNS TABLE (h3 h3index, x integer, y integer)
AS $$
WITH
geoms AS (
SELECT
h3,
ST_Transform(
h3_cell_to_geometry(h3),
ST_SRID(poly)
) AS geom
FROM (
SELECT __h3_raster_polygon_to_cells(rast, poly, resolution, 0.0) AS h3
) t),
coords AS (
SELECT
h3,
ST_WorldToRasterCoordX(rast, geom) AS x,
ST_WorldToRasterCoordY(rast, geom) AS y
FROM geoms)
SELECT h3, x, y
FROM coords
WHERE
x BETWEEN 1 AND ST_Width(rast)
AND y BETWEEN 1 AND ST_Height(rast);
$$ LANGUAGE SQL IMMUTABLE PARALLEL SAFE;
CREATE OR REPLACE FUNCTION __h3_raster_polygon_to_cell_parts(
rast raster,
poly geometry,
resolution integer,
nband integer)
RETURNS TABLE (h3 h3index, part raster)
AS $$
DECLARE
nodata CONSTANT double precision := __h3_raster_band_nodata(rast, nband);
BEGIN
RETURN QUERY
SELECT c.h3, p AS part
FROM
__h3_raster_polygon_to_cell_boundaries_intersects(rast, poly, resolution) AS c,
ST_Clip(rast, nband, c.geom, nodata, TRUE) AS p
WHERE NOT ST_BandIsNoData(p, nband);
END;
$$ LANGUAGE plpgsql IMMUTABLE STRICT PARALLEL SAFE;
CREATE OR REPLACE FUNCTION __h3_raster_polygon_subpixel_cell_values(
rast raster,
poly geometry,
resolution integer,
nband integer)
RETURNS TABLE (h3 h3index, val double precision)
AS $$
SELECT
h3,
ST_Value(rast, nband, x, y) AS val
FROM __h3_raster_polygon_to_cell_coords_centroid(rast, poly, resolution);
$$ LANGUAGE SQL IMMUTABLE PARALLEL SAFE;
-- Raster processing: continuous data
CREATE TYPE h3_raster_summary_stats AS (
count double precision,
sum double precision,
mean double precision,
stddev double precision,
min double precision,
max double precision
);
CREATE OR REPLACE FUNCTION __h3_raster_to_summary_stats(stats summarystats)
RETURNS h3_raster_summary_stats
AS $$
SELECT ROW(
(stats).count,
(stats).sum,
(stats).mean,
(stats).stddev,
(stats).min,
(stats).max
)::h3_raster_summary_stats
$$ LANGUAGE SQL IMMUTABLE PARALLEL SAFE;
CREATE OR REPLACE FUNCTION __h3_raster_summary_stats_agg_transfn(
s1 h3_raster_summary_stats,
s2 h3_raster_summary_stats)
RETURNS h3_raster_summary_stats
AS $$
WITH total AS (
SELECT
(s1).count + (s2).count AS count,
(s1).sum + (s2).sum AS sum)
SELECT ROW(
t.count,
t.sum,
t.sum / t.count,
sqrt(
(
-- sum of squared values: (variance + mean squared) * count
(((s1).stddev * (s1).stddev + (s1).mean * (s1).mean)) * (s1).count
+ (((s2).stddev * (s2).stddev + (s2).mean * (s2).mean)) * (s2).count
)
/ t.count
- ((t.sum * t.sum) / (t.count * t.count)) -- mean squared
),
least((s1).min, (s2).min),
greatest((s1).max, (s2).max)
)::h3_raster_summary_stats
FROM total AS t
$$ LANGUAGE SQL IMMUTABLE STRICT PARALLEL SAFE;
CREATE AGGREGATE h3_raster_summary_stats_agg(h3_raster_summary_stats) (
sfunc = __h3_raster_summary_stats_agg_transfn,
stype = h3_raster_summary_stats,
parallel = safe
);
CREATE OR REPLACE FUNCTION __h3_raster_polygon_summary_clip(
rast raster,
poly geometry,
resolution integer,
nband integer)
RETURNS TABLE (h3 h3index, stats h3_raster_summary_stats)
AS $$
SELECT
h3,
__h3_raster_to_summary_stats(ST_SummaryStats(part, nband, TRUE)) AS stats
FROM __h3_raster_polygon_to_cell_parts(rast, poly, resolution, nband);
$$ LANGUAGE SQL IMMUTABLE PARALLEL SAFE;
CREATE OR REPLACE FUNCTION h3_raster_summary_clip(
rast raster,
resolution integer,
nband integer DEFAULT 1)
RETURNS TABLE (h3 h3index, stats h3_raster_summary_stats)
AS $$
SELECT __h3_raster_polygon_summary_clip(
rast,
__h3_raster_to_polygon(rast, nband),
resolution,
nband);
$$ LANGUAGE SQL IMMUTABLE STRICT PARALLEL SAFE;
COMMENT ON FUNCTION
h3_raster_summary_clip(raster, integer, integer)
IS 'Returns `h3_raster_summary_stats` for each H3 cell in raster for a given band. Clips the raster by H3 cell geometries and processes each part separately.';
CREATE OR REPLACE FUNCTION h3_raster_summary_centroids(
rast raster,
resolution integer,
nband integer DEFAULT 1)
RETURNS TABLE (h3 h3index, stats h3_raster_summary_stats)
AS $$
SELECT
h3_lat_lng_to_cell(ST_Transform(geom, 4326), resolution) AS h3,
ROW(
count(val),
sum(val),
avg(val),
stddev_pop(val),
min(val),
max(val)
)::h3_raster_summary_stats AS stats
FROM ST_PixelAsCentroids(rast, nband)
GROUP BY 1;
$$ LANGUAGE SQL IMMUTABLE STRICT PARALLEL SAFE;
COMMENT ON FUNCTION
h3_raster_summary_centroids(raster, integer, integer)
IS 'Returns `h3_raster_summary_stats` for each H3 cell in raster for a given band. Finds corresponding H3 cell for each pixel, then groups values by H3 index.';
CREATE OR REPLACE FUNCTION __h3_raster_polygon_summary_subpixel(
rast raster,
poly geometry,
resolution integer,
nband integer,
pixels_per_cell double precision)
RETURNS TABLE (h3 h3index, stats h3_raster_summary_stats)
AS $$
SELECT
h3,
ROW(
pixels_per_cell, -- count
val, -- sum
val, -- mean
0.0, -- stddev
val, -- min
val -- max
)::h3_raster_summary_stats AS stats
FROM __h3_raster_polygon_subpixel_cell_values(rast, poly, resolution, nband) t;
$$ LANGUAGE SQL IMMUTABLE PARALLEL SAFE;
CREATE OR REPLACE FUNCTION h3_raster_summary_subpixel(
rast raster,
resolution integer,
nband integer DEFAULT 1)
RETURNS TABLE (h3 h3index, stats h3_raster_summary_stats)
AS $$
DECLARE
poly CONSTANT geometry := __h3_raster_to_polygon(rast, nband);
pixel_area CONSTANT double precision := __h3_raster_polygon_pixel_area(rast, poly);
cell_area CONSTANT double precision := __h3_raster_polygon_centroid_cell_area(poly, resolution);
BEGIN
RETURN QUERY SELECT (__h3_raster_polygon_summary_subpixel(
rast,
poly,
resolution,
nband,
cell_area / pixel_area)).*;
END;
$$ LANGUAGE plpgsql IMMUTABLE STRICT PARALLEL SAFE;
COMMENT ON FUNCTION
h3_raster_summary_subpixel(raster, integer, integer)
IS 'Returns `h3_raster_summary_stats` for each H3 cell in raster for a given band. Assumes H3 cell is smaller than a pixel. Finds corresponding pixel for each H3 cell in raster.';
CREATE OR REPLACE FUNCTION h3_raster_summary(
rast raster,
resolution integer,
nband integer DEFAULT 1)
RETURNS TABLE (h3 h3index, stats h3_raster_summary_stats)
AS $$
DECLARE
poly CONSTANT geometry := __h3_raster_to_polygon(rast, nband);
cell_area CONSTANT double precision := __h3_raster_polygon_centroid_cell_area(poly, resolution);
pixel_area CONSTANT double precision := __h3_raster_polygon_pixel_area(rast, poly);
pixels_per_cell CONSTANT double precision := cell_area / pixel_area;
BEGIN
IF pixels_per_cell > 70
AND (ST_Area(ST_Transform(poly, 4326)::geography) / cell_area) > 10000 / (pixels_per_cell - 70)
THEN
RETURN QUERY SELECT (__h3_raster_polygon_summary_clip(
rast,
poly,
resolution,
nband
)).*;
ELSIF pixels_per_cell > 1 THEN
RETURN QUERY SELECT (h3_raster_summary_centroids(
rast,
resolution,
nband
)).*;
ELSE
RETURN QUERY SELECT (__h3_raster_polygon_summary_subpixel(
rast,
poly,
resolution,
nband,
pixels_per_cell
)).*;
END IF;
END;
$$ LANGUAGE plpgsql IMMUTABLE STRICT PARALLEL SAFE;
COMMENT ON FUNCTION
h3_raster_summary(raster, integer, integer)
IS 'Returns `h3_raster_summary_stats` for each H3 cell in raster for a given band. Attempts to select an appropriate method based on number of pixels per H3 cell.';
-- Raster processing: discrete data
CREATE TYPE h3_raster_class_summary_item AS (
val integer,
count double precision,
area double precision
);
CREATE OR REPLACE FUNCTION h3_raster_class_summary_item_to_jsonb(
item h3_raster_class_summary_item)
RETURNS jsonb
AS $$
SELECT jsonb_build_object(
'value', (item).val,
'count', (item).count,
'area', (item).area
);
$$ LANGUAGE SQL IMMUTABLE STRICT PARALLEL SAFE;
COMMENT ON FUNCTION
h3_raster_class_summary_item_to_jsonb(h3_raster_class_summary_item)
IS 'Convert raster summary to JSONB, example: `{"count": 10, "value": 2, "area": 16490.3423}`';
CREATE OR REPLACE FUNCTION __h3_raster_class_summary_item_agg_transfn(
s1 h3_raster_class_summary_item,
s2 h3_raster_class_summary_item)
RETURNS h3_raster_class_summary_item
AS $$
SELECT
s1.val,
s1.count + s2.count,
s1.area + s2.area;
$$ LANGUAGE SQL IMMUTABLE STRICT PARALLEL SAFE;
CREATE AGGREGATE h3_raster_class_summary_item_agg(h3_raster_class_summary_item) (
stype = h3_raster_class_summary_item,
sfunc = __h3_raster_class_summary_item_agg_transfn,
parallel = safe
);
CREATE OR REPLACE FUNCTION __h3_raster_class_summary_part(
rast raster,
nband integer,
pixel_area double precision)
RETURNS SETOF h3_raster_class_summary_item
AS $$
SELECT ROW(
value::integer,
count::double precision,
count * pixel_area
)::h3_raster_class_summary_item
FROM ST_ValueCount(rast, nband) t;
$$ LANGUAGE SQL IMMUTABLE PARALLEL SAFE;
CREATE OR REPLACE FUNCTION __h3_raster_class_polygon_summary_clip(
rast raster,
poly geometry,
resolution integer,
nband integer,
pixel_area double precision)
RETURNS TABLE (h3 h3index, val integer, summary h3_raster_class_summary_item)
AS $$
WITH
summary AS (
SELECT
h3,
__h3_raster_class_summary_part(part, nband, pixel_area) AS summary
FROM __h3_raster_polygon_to_cell_parts(rast, poly, resolution, nband) t)
SELECT h3, (summary).val, summary
FROM summary;
$$ LANGUAGE SQL IMMUTABLE PARALLEL SAFE;
CREATE OR REPLACE FUNCTION h3_raster_class_summary_clip(
rast raster,
resolution integer,
nband integer DEFAULT 1)
RETURNS TABLE (h3 h3index, val integer, summary h3_raster_class_summary_item)
AS $$
DECLARE
poly CONSTANT geometry := __h3_raster_to_polygon(rast, nband);
BEGIN
RETURN QUERY SELECT (__h3_raster_class_polygon_summary_clip(
rast,
poly,
resolution,
nband,
__h3_raster_polygon_pixel_area(rast, poly)
)).*;
END;
$$ LANGUAGE plpgsql IMMUTABLE STRICT PARALLEL SAFE;
COMMENT ON FUNCTION
h3_raster_class_summary_clip(raster, integer, integer)
IS 'Returns `h3_raster_class_summary_item` for each H3 cell and value for a given band. Clips the raster by H3 cell geometries and processes each part separately.';
CREATE OR REPLACE FUNCTION __h3_raster_class_summary_centroids(
rast raster,
resolution integer,
nband integer,
pixel_area double precision)
RETURNS TABLE (h3 h3index, val integer, summary h3_raster_class_summary_item)
AS $$
SELECT
h3_lat_lng_to_cell(ST_Transform(geom, 4326), resolution) AS h3,
val::integer AS val,
ROW(
val::integer,
count(*)::double precision,
count(*) * pixel_area
)::h3_raster_class_summary_item AS summary
FROM ST_PixelAsCentroids(rast, nband)
GROUP BY 1, 2;
$$ LANGUAGE SQL IMMUTABLE PARALLEL SAFE;
CREATE OR REPLACE FUNCTION h3_raster_class_summary_centroids(
rast raster,
resolution integer,
nband integer DEFAULT 1)
RETURNS TABLE (h3 h3index, val integer, summary h3_raster_class_summary_item)
AS $$
SELECT __h3_raster_class_summary_centroids(
rast,
resolution,
nband,
__h3_raster_polygon_pixel_area(rast, __h3_raster_to_polygon(rast, nband))
);
$$ LANGUAGE SQL IMMUTABLE STRICT PARALLEL SAFE;
COMMENT ON FUNCTION
h3_raster_class_summary_centroids(raster, integer, integer)
IS 'Returns `h3_raster_class_summary_item` for each H3 cell and value for a given band. Finds corresponding H3 cell for each pixel, then groups by H3 and value.';
CREATE OR REPLACE FUNCTION __h3_raster_class_polygon_summary_subpixel(
rast raster,
poly geometry,
resolution integer,
nband integer,
cell_area double precision,
pixel_area double precision)
RETURNS TABLE (h3 h3index, val integer, summary h3_raster_class_summary_item)
AS $$
SELECT
h3,
val::integer AS val,
ROW(
val::integer,
cell_area / pixel_area,
cell_area
)::h3_raster_class_summary_item AS summary
FROM __h3_raster_polygon_subpixel_cell_values(rast, poly, resolution, nband);
$$ LANGUAGE SQL IMMUTABLE PARALLEL SAFE;
CREATE OR REPLACE FUNCTION h3_raster_class_summary_subpixel(
rast raster,
resolution integer,
nband integer DEFAULT 1)
RETURNS TABLE (h3 h3index, val integer, summary h3_raster_class_summary_item)
AS $$
DECLARE
poly CONSTANT geometry := __h3_raster_to_polygon(rast, nband);
BEGIN
RETURN QUERY SELECT (__h3_raster_class_polygon_summary_subpixel(
rast,
poly,
resolution,
nband,
__h3_raster_polygon_centroid_cell_area(poly, resolution),
__h3_raster_polygon_pixel_area(rast, poly)
)).*;
END;
$$ LANGUAGE plpgsql IMMUTABLE STRICT PARALLEL SAFE;
COMMENT ON FUNCTION
h3_raster_class_summary_subpixel(raster, integer, integer)
IS 'Returns `h3_raster_class_summary_item` for each H3 cell and value for a given band. Assumes H3 cell is smaller than a pixel. Finds corresponding pixel for each H3 cell in raster.';
CREATE OR REPLACE FUNCTION h3_raster_class_summary(
rast raster,
resolution integer,
nband integer DEFAULT 1)
RETURNS TABLE (h3 h3index, val integer, summary h3_raster_class_summary_item)
AS $$
DECLARE
poly CONSTANT geometry := __h3_raster_to_polygon(rast, nband);
cell_area CONSTANT double precision := __h3_raster_polygon_centroid_cell_area(poly, resolution);
pixel_area CONSTANT double precision := __h3_raster_polygon_pixel_area(rast, poly);
pixels_per_cell CONSTANT double precision := cell_area / pixel_area;
BEGIN
IF pixels_per_cell > 70
AND (ST_Area(ST_Transform(poly, 4326)::geography) / cell_area) > 10000 / (pixels_per_cell - 70)
THEN
RETURN QUERY SELECT (__h3_raster_class_polygon_summary_clip(
rast,
poly,
resolution,
nband,
pixel_area
)).*;
ELSIF pixels_per_cell > 1 THEN
RETURN QUERY SELECT (__h3_raster_class_summary_centroids(
rast,
resolution,
nband,
pixel_area
)).*;
ELSE
RETURN QUERY SELECT (__h3_raster_class_polygon_summary_subpixel(
rast,
poly,
resolution,
nband,
cell_area,
pixel_area
)).*;
END IF;
END;
$$ LANGUAGE plpgsql IMMUTABLE STRICT PARALLEL SAFE;
COMMENT ON FUNCTION h3_raster_class_summary(raster, integer, integer)
IS 'Returns `h3_raster_class_summary_item` for each H3 cell and value for a given band. Attempts to select an appropriate method based on number of pixels per H3 cell.';