dbaston

-- Copyright Paul Ramsey, 2014
-- http://gis.stackexchange.com/questions/94203/how-to-group-connected-linestrings-in-postgis
 
drop table lines;
create table lines ( id integer primary key, geom geometry(linestring) );
insert into lines (id, geom) values ( 1, 'LINESTRING(0 0, 0 1)');
insert into lines (id, geom) values ( 2, 'LINESTRING(0 1, 1 1)');
insert into lines (id, geom) values ( 3, 'LINESTRING(1 1, 1 2)');
insert into lines (id, geom) values ( 4, 'LINESTRING(1 2, 2 2)');
insert into lines (id, geom) values ( 11, 'LINESTRING(10 10, 10 11)');

dbaston

SELECT old.column_name as column_1141, old.data_type as type_1141, new.column_name as column_1142, new.data_type as type_1142
FROM
(SELECT * FROM information_schema.columns WHERE table_schema = 'old_schema' AND table_name = 'old_table') old
FULL OUTER JOIN
(SELECT * FROM information_schema.columns WHERE table_schema = 'new_schema' AND table_name = 'new_table') new
USING (column_name)
WHERE old.column_name IS DISTINCT FROM new.column_name
   OR old.data_type != new.data_type
ORDER BY COALESCE(old.column_name, new.column_name) ASC;

dbaston

package com.maponics.algorithm;

import com.vividsolutions.jts.geom.Coordinate;
import com.vividsolutions.jts.geom.Geometry;
import com.vividsolutions.jts.operation.polygonize.Polygonizer;
import com.vividsolutions.jts.operation.union.UnaryUnionOp;

import java.util.*;
import java.util.concurrent.Callable;

dbaston

-- convert 'text' fields into varchar fields of an appopriate length (useful for exporting to shp, dbf, etc)

CREATE OR REPLACE FUNCTION set_varchar_length (schema_name text, table_name text) RETURNS VOID AS $$
DECLARE rec record;
DECLARE len int;
DECLARE qry text;
DECLARE is_first boolean;
BEGIN
  qry := 'ALTER TABLE ' || quote_ident(schema_name) || '.' || quote_ident(table_name);
  is_first := true;

dbaston

import com.vividsolutions.jts.geom.Geometry;
import com.vividsolutions.jts.geom.util.GeometryCombiner;
import com.vividsolutions.jts.index.strtree.STRtree;

import java.util.Collection;
import java.util.List;
import java.util.stream.Collectors;

public class ParallelCascadedPolygonUnion {
    public static Geometry union(Collection<Geometry> geoms) {

dbaston

PG_FUNCTION_INFO_V1(cluster_intersecting_window);
Datum cluster_intersecting_window(PG_FUNCTION_ARGS)
{
	WindowObject win_obj = PG_WINDOW_OBJECT();
	uint32_t row = WinGetCurrentPosition(win_obj);
	uint32_t ngeoms = WinGetPartitionRowCount(win_obj);	
	uint32_t* cluster_assignments = WinGetPartitionLocalMemory(win_obj, ngeoms * sizeof(uint32_t));

	if (row == 0) /* beginning of the partition; do all of the work now */
	{

dbaston

FROM phusion/baseimage
 
RUN apt-get update && apt-get install -y \
    build-essential \
    git \
    bison \
    flex \
    zlib1g-dev \
    autoconf \
    libtool \

dbaston

FROM phusion/baseimage

RUN apt-get update && apt-get install -y build-essential git bison flex zlib1g-dev autoconf libtool libxml2-dev libproj-dev libjson0-dev libcunit1-dev libxml2-utils xsltproc imagemagick docbook-xsl docbook-mathml libgdal-dev wget cmake libgmp-dev libmpfi-dev libboost-thread-dev libboost-system-dev
RUN git clone --depth 1 https://github.com/postgres/postgres.git && cd postgres && ./configure --without-readline && make -j6 && make install && make clean && cd .. && rm -rf postgres
RUN git clone --depth 1 https://github.com/libgeos/libgeos.git && cd libgeos && ./autogen.sh && ./configure --libdir=/usr/lib && make -j6 && make install && make clean && cd .. && rm -rf libgeos
RUN wget https://github.com/CGAL/cgal/releases/download/releases%2FCGAL-4.7/CGAL-4.7.tar.gz && tar xzvf CGAL-4.7.tar.gz && rm CGAL-4.7.tar.gz && cd CGAL-4.7 && cmake . && make -j6 && make install && make clean && cd .. && rm -rf CGAL-4.7
RUN git clone --depth 1 https://github.com/Oslandia/SFCGAL.git && cd SFCGAL && cmake

dbaston

-- Divide an input geometry into equal-length portions of the specified length.
-- The final segment will contain the "unused" portion of the line and will be 
-- shorter than the others.
--
-- Note that segment_length is in the units of the geometry's coordinate system,
-- i.e. degrees for 4326.  To use the function with geographic coordinates and
-- a distance in meters, it is recommended to project the geometry into a 
-- planar coordinate system, e.g. using _ST_BestSRID.
CREATE OR REPLACE FUNCTION pg_temp.DivideLine(g geometry, segment_length double precision)
RETURNS SETOF geometry AS $$

dbaston

def masked_vectorize(fn):
    vectorized = np.vectorize(fn)

    def ret(*args, **kwargs):
        # In theory, it should be possible to replace this with
        # np.ma.logical_or.reduce([a.mask for a in args])
        # In practice, it seems to generate an error when the
        # internal storage of the arguments is different
        # ValueError: setting an array element with a sequence.
        masked_args = [arg for arg in args if isinstance(arg, np.ma.core.MaskedArray)]