I split polygons into separate polygons that where connected. when I ran the function vector/data management tools/split vector layers. it created .gpkg files. i want to export from QGIS as shapefiles and name them from a field in the attribute table . is there a function in QGIS to do a bulk export of individual polygons and rename based on field ?
I used the plugin Bulk vector exporter and used lupus re name
Related
I have applied a join on file and existing Cassandra table via joinWithCassandraTable. Now, I want to apply a filter on joinCassandraRDD. Here is the code and functionality which I have written for extraction of data:
var outrdd = sc.textFile("/usr/local/spark/bin/select_element/src/main/scala/file_small.txt")
.map(_.toString).map(Tuple1(_))
.joinWithCassandraTable(settings.keyspace, settings.table)
.select("id", "listofitems")
Here "/usr/local/spark/bin/select_element/src/main/scala/file_small.txt" is the text file which is having a list of ids. Now, I have some elements in another list, say userlistofitems=["jas", "yuk"], I need to search 'userlistofitems' sublist from 'listofitems' column of joinCassandraRDD.
We have around 2Million ids where we have several user_lists for which we have to extract the data from Cassandra. We are using versions spark=2.4.4, scala=2.11.12, and spark-cassandra-connector=spark-cassandra-connector-2.4.2-3-gda70746.jar.
Any help is highly appreciated.
References Used:
https://github.com/datastax/spark-cassandra-connector/blob/master/doc,
https://www.youtube.com/watch?v=UsenTP029tM
I would like to create some marks, where the information of the size comes from one dataset and the information of the color comes from another dataset.
Is this possible?
Or can I update created marks (created with dataset 1) by using information from a second dataset?
Yes, you can do it.
You can use lookup transform provided there is a lookup key in both datasets.
In this example, 'category' is the key that performs lookup transform
I am very new in GIS. I am using an existing data set which is a collection of triplets along with its trajectory ID. I need to find similar trajectories. I am using postgres as database. I have imported the data set and I want to visualize the trajectories.How can I convert the existing data in linestring?
Do you just need a LineString for each trajectory ID (meaning that by 'finding similar trajectories')? If so, you want to use ST_MakeLine (spatial aggregate version) in conjunction with ST_MakePoint. For PostGIS 9.0 and higher you could do something like:
SELECT points.trackid,
ST_MakeLine(points.point_geom ORDER BY points.timedetails) AS line_geom
FROM (SELECT data.trackid,
data.timedetails,
ST_MakePoint(data.longitude, data.latitude) AS point_geom
FROM your_table AS data) AS points
GROUP BY points.trackid;
I have import OpenstreetMap data into Postgres with gis extension with tool
osm2pgsql (-s option)
of course, I have the following tables
planet_osm_point
planet_osm_ways
....
Within planet_osm_ways I have a column called way, type geometry(LineString, 4326), content like following
"0102000020E6100000070000005E70BCF1A49F2540D3D226987B134840896764EB749F25403B5DCC858013484040D1860D609F2540C426327381134840CE50DCF1269F2540EF552B137E1348405AAB2CC02D9E2540F978324976134840D66F26A60B9D2540CE8877256E1348403CA81F2FFF9C2540BC1D86FB6D134840"
What is that ? How could I get all points along this way ?
Thanks a lot
That's hex-encoded extended well-known binary (EWKB) of a LINESTRING.
There are several methods to get the points along the way. To get individual coordinates as points, use ST_DumpPoints. Or to simply output the geometry in other human-readable formats (WKT, EWKT, GeoJSON, GML, etc.), see the relevant manual section.
I have a simple data table.
Schemas>resources>tables>image_data contains the columns
image_id(integer) raw_data(bytea)
How can I export this data to files named based on the image_id? Once I figure that out I want to use the image_id to name the files based on a reference in another table.
So far I've got this:
SELECT image_id, encode(raw_data, 'hex')
FROM resources.image_data;
It generates a csv with all the images as HEX, but I don't know what to do with it.
Data-sample:
"image_id";"encode"
166;"89504e470d0a1a0a0000000d49484452000001e0000003160806000000298 ..."