Questions tagged [indexing]
Indexing data structures is a general technique to improve the speed of data lookups.
74
questions
5
votes
2
answers
517
views
How to draw and index "trial plots"
I've starting using QGIS to extract data from drone survey maps of agricultural field trials. One of my biggest hurdles is actually drawing the polygons and identifying them in a way that I can ...
6
votes
5
answers
598
views
Reclassify raster values continuously instead of assigning them to specific groups
I want to create a Habitat Suitability Index (HSI). I have several variables (raster layers containing information about e.g. precipitation, slope, food resources, etc.).
I have to create an "...
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1
vote
1
answer
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GeoPandas geodataframe.cx() coordinate indexing not working for multipolygon
I am trying to apply the coordinate indexing .cx method to a GeoPandas geodataframe with a multipolygon geometry. I would like to plot a part of the full polygon. So far I have:
NP_shp.crs
<...
- 72.7k
2
votes
1
answer
81
views
Calculating field index based on feature attribute value using PyQGIS [closed]
Is there a way of finding to which field/column a feature attribute belongs?
For example, let's say I know feature[x] has an attribute of 0.17, I also know this must be between fields [12:17].
Can I ...
- 32.9k
9
votes
3
answers
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Getting field index from input vector layer in PyQGIS
I am currently trying to convert a python script from QGIS 2.18 to QGIS 3. Therefore, I am trying to integrate my python script into the template from @underdark: see here.
I am currently stepping ...
- 32.9k
2
votes
0
answers
442
views
Storing and indexing large trajectory dataset generated by cars' GPS [closed]
I have a large trajectory dataset generated by cars' GPS. Since I will do some data mining work on them, I need an efficient way to store and index them.
I read some papers about Trajectory Indexing (...
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1
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2
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GeoPandas .explode() FutureWarning: Currently, index_parts defaults to True, but in the future, it will default to False to be consistent with Pandas
I have a simple GeoDataFrame containing 2 records, with MultiPolygonZ having several single parts as geometry elements. When I try to split those in their single parts using the .explode() method, it ...
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1
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1
answer
189
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Extract the raster values for geometry using Python
I tried to extract the pixel value of the raster for the points with the following code.
for point in df['geometry']:
x = point.xy[0][0]
y = point.xy[1][0]
row, col = raster.index(x,y)
...
- 72.7k
1
vote
0
answers
52
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Merging rasters identified by clipped raster index
I have a very large set of data heavy ECW aerial photos. There is a polygon vector index of the rasters which identifies the name and other attributes of each raster. My end goal is to be able to ...
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0
answers
371
views
How to create a GIST index on locations within a JSONB array column?
I have a JSONB column with an array of locations. I want to do a Postgis GiST index on each of the array items.
For example:
[{
"location":{
"type": "Point",
...
- 65.2k
0
votes
0
answers
358
views
Could not write feature into OUTPUT using PyQGIS
I got a shapefile layerStreetAxis from these file I run the code below. For the most of cases the script works well, but I found a case where the script stops in uniqueStreetNamesAxis and gives me the ...
- 76.9k
26
votes
1
answer
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Setting up indexes for PostGIS distance queries
I'm building an application that is supposed to query and return every Record in a table that is X kilometers away from PointX. Records and PointX's positions are determined from (long/lat) ...
- 20.1k
2
votes
1
answer
175
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Spatial index creation in GeoServer when adding PostGIS store
If we are adding a GeoServer store using the shapefile section, it is possible to check the option so GeoServer creates spatial index files, Is this feature available when we add store using postGIS ...
- 20.1k
1
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1
answer
206
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Trouble indexing data when following the cube-in-a-box installation steps
I have been trying to follow the cube-in-a-box installation steps and have ran into an issue when getting to the last step where we index the data.
I have taken the following steps when installing ...
6
votes
3
answers
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Create an SDO_GEOMETRY view from a non-spatial table?
Let's say I have an Oracle database table with latitudes and longitudes. I don't have access to modify the schema of this table, or even create tables. However, I can create views and indexes on those ...
- 1,132
0
votes
0
answers
567
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Spatial indexes with RTree for polygons
I am trying to understand about how R-tree works for polygon data. In other words, polygon is a list of vertices (points), however, I am wondering how spatial index can recognize the order of points ...
- 20.1k
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0
answers
138
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Indexing line segments with R-Tree
I have made a small unweighted graph consisting of 20 nodes and 28 edges. I would like to understand how a R-Tree indexing would index the the graph.
Could anyone explain how the R-tree indexed such ...
- 65.2k
3
votes
2
answers
640
views
Indexing USGS Landsat Collection 2 Level 2 datasets into Open Data Cube
I'm trying to ingest data using Landsat 8 Collection 2 Level 2 data into the Open Data Cube, but I couldn't find any examples for data preparation.
How do I index USGS Landsat Collection 2 datasets ...
- 115
1
vote
2
answers
246
views
Indexing Copernicus Global Land Service data into ODC
I would like to index Copernicus Global Land Service data (that we can find in this site: https://land.copernicus.vgt.vito.be/manifest/) into Open Data Cube.
How can I do it without the need to ...
- 108
2
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0
answers
64
views
Indexing USGS Landsat Collection 2 data in Open Data Cube [duplicate]
The USGS Landsat Collection 2 data has been released for a while and there's no clear way to index it into the Open Data Cube.
Is there a prepare script or some other method that can be used to index ...
- 65.2k
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vote
1
answer
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Can I use Copernicus Land Services data on Open Data Cube?
I need to use Copernicus Land services data (that I can take from the official website of Copernicus land: https://land.copernicus.eu/) on Open Data Cube.
How can I do it?
How can I index this data?
- 65.2k
1
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1
answer
287
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Error while indexing Sentinel 2 data on Open Data Cube
If I have sentinel 2 data:
which .py file do I have to use to create dataset?
which .yaml file do I have to use for product?
I took file from these 3 providers (https://earthexplorer.usgs.gov/ , ...
- 13.5k
0
votes
1
answer
66
views
GeoServer using read only database
Can GeoServer use an Oracle database that is in a read-only state or does it need the ability to generate its own indexes if existing databases do not have the necessary indexes already generated?
- 81.5k
2
votes
1
answer
176
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Indexing Multi-Band images in OpenDataCube
I have a Sentinel2 based product with the following product definition. It has 2 bands in it
name: product_name
description: Product Name
metadata_type: eo3
metadata:
product:
name: '...
- 246
0
votes
0
answers
69
views
Index issue with digitising OS MasterMapdata from OS Data Hub in QGIS
Using QGIS 3.18.3 (Zurich). From the OS Data Hub (https://osdatahub.os.uk/) I've brought in the OS MasterMap "Topographic Line" data, via WFS/OGC API - Features option, and this has loaded ...
- 65.2k
2
votes
0
answers
92
views
Do the MTL.txt and ANG.txt need to be changed after reclassification using QGIS is done on one or two bands?
I had reclassified("Reclassify by table" in QGIS) the SWIR1 band value for a coastal erosion project to differentiate the land and the water better uisng QGIS and then replaced the SWIR1....
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1
vote
1
answer
385
views
Indexing new data in the Open Data Cube
The cube in a box comes with an indexing script for Sentinel-2 data, as below
lon_center = XX.YY
lat_center = XZ.XY
buffer = 0.5
bbox = [lon_center - buffer, lat_center - buffer, lon_center + buffer,...
CommunityBot
- 1
0
votes
1
answer
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views
GEE: Indexing a List of Lists inside a property of a FeatureCollection
I'm running the LandTrendr algorithm in GEE over multiple points of interest, which leaves me with a FeatureCollection having a list of lists in one the properties for every feature.
Out if this list ...
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0
answers
819
views
Resetting system index of feature collection in Google Earth Engine?
I am using the sample to repeatedly sample from an image and because I am sampling many times and merging the collections, the ids are coming like 1_1_1_1_1_2_8. I am pretty new to EE so I am not sure ...
2
votes
1
answer
303
views
What permissions needed to add an index with a protected version?
Using arcpy and ArcGIS 10.1 SP1 (Build 3143) against an Oracle 11g enterprise geodatabase, I am trying to add an index to an existing attribute in an existing feature class:
arcpy.AddIndex_management(...
CommunityBot
- 1
8
votes
3
answers
2k
views
Solving the problem with the "Indexing data" window while editing
When trying to edit a vector layer using node tool, I get constantly the next message:
Normally it appears once at the beginning of the edition and then it doesn't show any more, but now I get it ...
- 3,535
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1
answer
520
views
How to index mbtiles to speed up load time?
I have created a mbtile based on OpenStreetMap data with Maperitive using the command:
generate-mbtiles file=Path\filename.mbtiles maxzoom=16
Loading the file in QGIS 2.14.0 and zooming takes 15-30 ...
CommunityBot
- 1
0
votes
1
answer
2k
views
Exception java.lang.ClassNotFoundException while updating geomesa indices
I have some tables in geomesa, such as MyFeature. I have to verify if it is possible to modify the indices.
I'm trying the following instruction from CLI:
geomesa-accumulo add-attribute-index -u ...
CommunityBot
- 1
1
vote
1
answer
277
views
How R-Trees, R*-Trees can be used to index the Road Network?
I am trying to understand the Tree Indexing method of the Road network. In R-Tree the Minimum Bounding Rectangle is used to store the data points, but how it can hold the line segments of the Map? Or ...
CommunityBot
- 1
0
votes
1
answer
565
views
Rebuilding indexes in file geodatabase using ArcPy
I am trying to automate the rebuild of file geodatabase indexes using ArcPy v10.6, but I encounter an ERROR 000837 The workspace is not the correct workspace type.
Question: If arcpy....
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1
vote
0
answers
676
views
geometry point and varchar multicolumn index in PostgreSQL
Is it possible to create a multicolumn index on a geometry point column and a varchar column? For example, say I have a geometry point column called "location_point" and a varchar column called "zip". ...
- 421
0
votes
0
answers
412
views
Finding neighbors of latitude longitude pair location
I have a list of points (more than a few million) defined by latitude and longitude.
I want to find out the neighbors of each point.
For example, I want to know for each point, what the nearest point, ...
- 16.3k
3
votes
1
answer
375
views
Indexing to Open Data Cube not working for land cover map
I'm trying to index a clipped version of ESA's 2015 land cover map into an Open Data Cube instance. I've written a product specification yaml and a yaml for te actual product itself and it indexes ...
- 338
1
vote
2
answers
568
views
Why the indexes for the attributes are not being used when GeoServer asks PostGIS?
I am working on a WMS to publish data with GeoServer (2.11.0). Tables come from PostGIS (PostgreSQL 9.6). I have indexed geometries on the tables and i have also indexed attributes which are being ...
- 20.1k
1
vote
0
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118
views
PostGIS: Is it interesting to create an index on geom column and an alpha numeric field?
I would like to know if it's interesting to create an index on an other column than the geom one.
In some cases, I would like to do spatial analysis. If not, I would like to analyse only attributes.
...
- 1,094
2
votes
1
answer
2k
views
Subset raster stack with logical indeces R
Is it possible to subset a raster stack by indexing on a logical vector?
r1 <- raster(nrow = 100, ncol = 100)
r1[] <- round(runif(ncell(r1), 1, 4), 0)
r2 <- raster(nrow = 100, ncol = 100)
r2[...
- 63.9k
0
votes
1
answer
324
views
R: Annual composite based on the median: How to get the index of the original layer for each pixel?
What I want:
I have a list of rasterstacks which are timeseries (300+ layers) for different bands. The timeseries are irregular, and therefore I want to create annual composites based on median ndvi. ...
- 327
17
votes
1
answer
233
views
Alternative indexing methods for point set operations
It is common to use a bounding box spatial index to improve performance when working with a large number of features. Where operations are performed against individual geometries with a large number ...
- 65.2k
0
votes
1
answer
2k
views
Generating map sheets and index page in QGIS?
I have a project in QGIS and would like to print it out in multiple pages. I know how to set the pages one by one (pages 1,2,3), but I would like to know if there is an easy way to do the index page ...
- 24.8k
2
votes
1
answer
1k
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Create shapefile from file.csv using python pyshp module
I followed the guide given here Automate the writing records from csv to shapefile using pyshp module. I follow this procedure and the code doesn't give me any error, but it doesn't produce any output....
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1
answer
336
views
Is it possible to take advantage of lowercase index on column using CQL filter on WFS?
I am querying a WFS housed in geoserver - the data itself lives in a postgresql database. I would like to run case insensitive queries against the WFS and see there is an option to specify ...
- 81.5k
1
vote
3
answers
2k
views
How to speed up query performance with PostGIS data served up in GeoServer and OpenLayers?
I have published a table with @ 6 million polygons to geoserver, and have built a tool using the OpenLayers filter class to query the data. The performance is abysmally slow, often times not ever ...
1
vote
1
answer
97
views
Edit specific indexes from a feature of Attribute Table QGIS [closed]
I have an attribute table with many columns. One of them describes a unique code. The column's name is "specialcode" and the column's type is String(254). I want to do the following:
Sort every ...
- 3,543
1
vote
1
answer
826
views
indexes to optimize ST_Contains and ST_Overlaps for geoms in two tables
I'm a programmer getting into the wonderful world of GIS. I just had a fun day optimizing queries (took one from 60s to 3.4s, and another from 38s to 1.2s). Below is the last query that I can't seem ...
- 20.1k
1
vote
1
answer
220
views
Changing The coverage Atlas layer
I created a coverage layer ( polygon) for an atlas. It contains rectangle polygons which define the boundary of sheets (somehow irregular indexing along my layer).
when I print the atlas without ...
- 24.8k