Questions tagged [indexing]

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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 ...
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32 views

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 ...
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1 vote
2 answers
136 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 ...
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2 votes
0 answers
63 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 ...
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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?
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1 vote
1 answer
137 views

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/ , ...
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1 answer
35 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?
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Using the resulting value from the difference between two rows in Python

I have a problem with being able to refer and use only the resulting value from the difference between two rows (that is: the first and the second values) in a column using Python. The difference ...
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2 votes
1 answer
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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: '...
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2 votes
0 answers
64 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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5 votes
2 answers
194 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 ...
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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 ...
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How can I create an indexed grid from a WMS service, with each element being the same size in pixels (512x512 for ex)

I understand how to make a fishnet-type grid (Vector->Research Tools->Create Grid), but this has definition via degrees, resulting in varying element sizes. I further can't see a way to index ...
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1 vote
1 answer
180 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,...
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3 votes
2 answers
333 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 ...
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0 votes
1 answer
249 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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6 votes
4 answers
207 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
156 views

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 ...
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1 answer
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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
253 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". ...
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181 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, ...
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1 answer
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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 ...
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1 vote
0 answers
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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. ...
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3 votes
1 answer
280 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 ...
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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[...
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640 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 ...
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1 vote
1 answer
200 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 ...
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8 votes
3 answers
4k views

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 ...
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0 votes
1 answer
232 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. ...
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1 answer
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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 ...
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1 vote
1 answer
224 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 ...
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1 vote
3 answers
1k 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 ...
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1 vote
1 answer
54 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 ...
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1 answer
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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 ...
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1 vote
1 answer
152 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 ...
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2 votes
1 answer
1k views

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 vote
1 answer
315 views

Build a polygon raster as indexing grid with SQL

According to the plugin Indexed Vector Grid which builds a polygon raster from shape bounds and name every cell as "A1, A2, A3 ...", I need a more advance solution, which I can use for hundreds of ...
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22 votes
1 answer
13k views

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) ...
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0 votes
1 answer
736 views

Feature Grid Layer to cluster features at higher zoom levels in Leaflet

I was wondering if there is a plug in for Leaflet which accomplishes clustering features within a grid layer. Similar to marker clusters this allows for rendering an abstraction of all features with a ...
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1 vote
2 answers
378 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 ...
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4 votes
2 answers
499 views

Determining best neighbourhood search radius for Topographic Position Index (TPI) for predictive soil mapping?

I'm not sure how to determine the best input values for a search radius to create a TPI for the purpose of predictive soil mapping. Would this depend on the spatial extent of the area I wish to map?...
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2 votes
1 answer
503 views

How would I determine my search radius when conducting a Topographic Position Index in SAGA GIS?

When running the TPI tool in SAGA, I get this parameter-entry window: Under the section highlighted in the red box, what do these parameters mean? Do the search/neighbourhood grouping parameters mean ...
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0 votes
1 answer
624 views

Creating Topographic Position Index in SAGA GIS?

I am trying to create a TPI from a DEM tiff file in SAGA but keep getting the following result: I'm just not sure what I'm doing wrong.
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2 votes
0 answers
1k views

How to speed up slow performance on postgresql Postgis?

I'm using postgresql 9.6 as my database. It takes too much time than the query itself. The query take about 160ms which is not as good as the wanted performance. My query is like : SELECT DISTINCT ...
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2 votes
2 answers
340 views

What is GiST page size using PostGIS?

How can I check the page size (and maybe modify) of the GiST index in PostGIS? From the PostGIS documentation, I quote: "... GiST indexes support the concept of "lossiness" which is important ...
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2 votes
1 answer
170 views

ArcGIS: raster table only shows two groups of cells

I am working on the raster map below, which has 352 rows and 350 columns. When doing Data Management Tools->Raster->Raster Properties->Build Raster Attribute Table in ArcGIS 10.3.1 (licence ...
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57 votes
3 answers
13k views

What is the purpose of PostGIS on PostgreSQL?

PostgreSQL already supports spatial data types, operators and indexing. What does PostGIS provide exactly that made it necessary to exist as an extension to PostgreSQL? Why don't we all just use ...
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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 ...
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2 votes
1 answer
210 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(...
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1 vote
0 answers
203 views

Determining Highest Position in QGIS for raster stacks with 10+ images?

I want to follow up on this question from last year Emulating ArcGIS Highest Position tool in QGIS? Here the question is if QGIS has a tool like the "highest position" tool in ArcGIS, where, in a ...
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