To show, hide, extract, or remove particular data from a larger set, narrowing it down, or the specific criteria used to do so.

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11
votes
2answers
3k views

How to filter big datasets in Geoserver WMS?

Is there a good way to filter datasets with approx 50,000 features in Geoserver? I'd have to select between 100 and 200 features based on ids. These ids are different from the FeatureIds. Couldn't ...
8
votes
1answer
1k views

How to apply a Majority filter in GRASS GIS?

I was wondering if someone could help me write a majority filter for GRASS GIS. I have this map (see below) which I need to run a filter over to make the red areas a bit more dominant. I know I can ...
8
votes
1answer
690 views

Create custom Authentication filter in GeoServer 2.3.0

Context In my current project, I've the requirement to validate that requests coming to GeoServer (2.3.0) are allowed. The project holds those facts: the GS client cannot provide the principal ...
7
votes
3answers
534 views

Filtering out canopies and buildings from DSM to have a bare earth elevation

Can anyone suggest methods in filtering out trees and buildings from a DSM so as to come up with a reliable DEM? What I have is a grid from a LIDAR data (.tif file, with 1m resolution). I was going ...
7
votes
2answers
634 views

Using ArcGIS to filter cells where 7 or 8 of neighbors are different

I have land cover data that I would like to clean using some generalization tools. Majority filter does almost exactly what I want, but is missing one key option. Majority filter allows you to change ...
6
votes
2answers
687 views

How to de-noise a DSM

I have created a DEM, DSM, and nDSM from a LiDAR Point Cloud using SAGA-GIS. I extracted the appropriate returns from the point cloud, then converted to grid, and then closed gaps to fill in any ...
6
votes
1answer
808 views

PostGIS query vs QGIS filter

I have a PostGIS dataset with around 3 million shapes. I only need to view about 1,500 of these shapes at any given time, but the shapes I need to see depends on which feature is selected in a ...
6
votes
1answer
2k views

How to filter wrong GPS readings?

I have absolutely no experience with GIS, it just so happens that one of the hobby projects I am doing at the local hackerspace includes tracking a model boat with a GPS... I hope this is the right ...
6
votes
1answer
2k views

Problem with WFS filters (BBOX, INTERSECTS)

I'm trying to get a feature/features from a small area using the BBOX (or INTERSECTS) filter in my WFS query. I should be expecting only a small set of features or a single feature and yet the query ...
5
votes
2answers
540 views

Filtering Overpass-API by country

Does anyone know how to perform a overpass-api request like this? "Show me all banks in Germany"? I could just show all 'amenity = bank' in a specific bounding-box. But Germany (or most of all ...
5
votes
1answer
483 views

Getting feature at point in C#

I want to get the feature at where mouse was clicked in map. So I was wondering how to get features which intersects with that point. Plus I was wondering how can I check what type of object it is ...
5
votes
2answers
1k views

OpenLayers.Filter.Comparison.LIKE doesn't filter special characters!

it seems like OpenLayers.Filter.Comparison.LIKE doesn't filter special characters! for example, filter = new OpenLayers.Filter.Comparison({ type: OpenLayers.Filter.Comparison.LIKE, ...
4
votes
2answers
1k views

What is the best approach to using IQueryFilter.WhereClause in ArcObjects?

What is your preferred / best approach to using IQueryFilter.WhereClause statements in ArcObjects (e.g. when selecting features by attributes)? You need to check the source type (shapefile / personal ...
4
votes
2answers
121 views

Reconstructing MODIS time-series applying Savitzky-Golay Filter with Python/Numpy

I want to apply the 'Savitzky-Golay' (savgol) filter to my time series, MODIS dataset, to remove noise (i.e., cloud pixels, etc.) in my data. MODIS have quality flags that indicates the reliability of ...
4
votes
1answer
6k views

How to filter features in a layer?

I am trying to display certain features in a shapefile-based layer using QGIS. I have found the subset function in the properties panel, which does exactly what i want, but is too tedious given that I ...
4
votes
3answers
3k views

How to properly utilize DWITHIN Spatial Filter in OpenLayers

Given the following code: var points = []; points.push(new OpenLayers.Geometry.Point(-110, 38)); points.push(new OpenLayers.Geometry.Point(-108, 40)); var lineString = ...
4
votes
1answer
271 views

Given a known batch of mobile-obtained gps data with timestamps, what algorithms can be used to clean it?

I'm working on the backend for an iOS/Android app that collects locations every hour and syncs with the server every three hours. The mobile apps themselves are not under my control and so I can't ...
4
votes
0answers
26 views

QGIS Atlas: Filter maps based on attributes (more than one)?

I have a series of maps with the same geographic boundaries but with different set of points (from the same layer). I would like to create an Atlas where the change is based on the attributes. A ...
3
votes
2answers
4k views

OpenLayers: Combine multiple OGC filters

I have two OGC filters client side: <ogc:Filter xmlns:ogc="http://www.opengis.net/ogc"> <ogc:PropertyIsEqualTo matchCase="true"> ...
3
votes
2answers
65 views

Copy/convert selection into filter/query builder of QGIS?

Can anyone tell me if it is possible (and how) to convert or copy a selection on a layer (that has not been created through "select by expression", but instead by irregular selections from a canvas, ...
3
votes
2answers
123 views

QGIS Forms - Limit list values based on a previous field

Looking for assistance to set up appropriate configuration to enable drop-down lists values to be filtered based on a previous value. Basically, I have a 3-tiered categorisation structure to one of ...
3
votes
1answer
145 views

How do you classify unclassified pixels in a land cover geotiff tile?

While printing out the raw pixel values of a GEOTIFF land cover tile I found 90 % of pixels have normal values i.e. those that the documentation describes (8 bit integers describing a land cover ...
3
votes
2answers
43 views

Filtering information in two attribute tables using QGIS?

I'm an amateur in QGIS so please forgive me for not using the correct definitions. I have a polygon map (shape file) with the neighborhoods of my city. Each one of this neighborhoods has it's own ...
3
votes
1answer
384 views

How to filter layer of osm data?

I have a table osm_roads that has a column named geometry geometry geometry(LineString,900913). If I want to filter a city to draw districts, I cannot do it by geographic coordinates? What if in ...
3
votes
1answer
1k views

Openlayers: OGC Filter problem

I have a problem with OGC filter. My layer in OpenLayers has this filter: filter: new OpenLayers.Filter.Comparison({ type: OpenLayers.Filter.Comparison.BETWEEN, property: ...
3
votes
2answers
1k views

OpenLayers spatial filter polygon problem

I've got a dataset of English Counties (currently cut down for testing) that I'm serving from SQL 2008 using MapServer and OpenLayers. The features in my dataset are appearing in the right location on ...
3
votes
1answer
964 views

Case Insensitive WFS Attribute Search with ArcGIS Server?

I'm using ArcGIS 9.3.1 to host WMS and WFS services. I have a map (.mxd file) with a layer whose attribute table includes fields with mixed-case string data. When I open this map in ArcMap and ...
3
votes
0answers
62 views

Queen vs Rook neighborhood

Queen and rook neighborhoods are two common ways to calculate statistics for a focal cell. They are also known an Moore and (von) Neumann neighborhoods. I think a "bishop version", i.e. from lower ...
3
votes
1answer
120 views

How to remove spikes from grid in SAGA GIS? [duplicate]

I tried to get a grid by interpolating LAS file using Ordinary Kriging. But the product grid has many pixels which values strongly stands out from average surface - I mean one pixel sinks nad spikes. ...
3
votes
0answers
135 views

Filtered SimpleFeatureCollection really slow on Map and other operations

I'm working with a shapefile having about 85.000 features. I need to select some of these using a filter and then showing these on a map. Now... If I draw the entire shapefile's features the creation ...
3
votes
0answers
492 views

SLD filter with embedded strTrim function in Geoserver

Using Geoserver 2.2.2 (GeoTools Version 8.4) on Windows 7, I'm trying to create a SLD that trims the leading and trailing spaces of a string property (using the strTrim function) and compares it to a ...
2
votes
1answer
2k views

WFS 2.0 with bbox filter and attribute filter

I am trying to get the following WFS GET request to work: wfs = "service=WFS&version=2.0.0&request=GetFeature", name = "&typeName=storeName:layerName", bboxFilter = '&bbox=' + ...
2
votes
2answers
549 views

How can I tell mapserver to ignore a filter that is set in a mapfile?

How can I tell mapserver to ignore a filter that is set in a mapfile? I am displaying a wms layer with point features using mapserver. In one of the layers in my mapfile I have defined a filter ...
2
votes
1answer
129 views

spatial data filtering without GIS?

I have access to a database here (description of the columns are also available) containing spatial data in text format and with WGS84-EPSG:4326 coordinates. I would like to only select data in my ...
2
votes
1answer
1k views

Filtering a raster by pixel value ? (Qgis)

I have downloaded Globcover data in GeoTIFF format. I want to create a new grid which only has values where the Globcover data (the only band in the TIF file) has one certain value (==190). Can I do ...
2
votes
2answers
5k views

OpenLayers WFS protocol: work with filters if the protocol is defined out of layer constructor

follow question:wfs-load-feature-check the scenario is: i am trying to load a WFS layer, since it takes a while to load all features, I want to give user a notice while waiting for response. the ...
2
votes
1answer
187 views

Geoserver WMS Filtering: Clipping geometry against a polygon

My data set is a series of multilinestrings representing roads. During a WMS GetMap request, I want to specify a polygon and display only the portions of those roads that fall within the polygon. I am ...
2
votes
2answers
2k views

Change marker color based on GeoJSON filter in Leaftlet

This is what I would like to do: Display all features of a GeoJSON file using Leaflet. Provide a text box where a property can be entered, if any of the GeoJSON properties match with what is entered ...
2
votes
2answers
1k views

Creating New Layer After Sorting Attribute Table using QGIS?

I have been self-teaching myself some open source GIS. I downloaded QGIS and have been following this four part tutorial - ...
2
votes
2answers
3k views

What class/types of smartphone chipsets support GPS, A-GPS, GLONASS AND have extended kalman filtering?

I've been testing several Android phones (all running Android 4+) Sony Xperia T, Moto G, Nexus and HTC 1 which are all giving decent tracks (all of which use GPS/GLONASS) However we are also using ...
2
votes
2answers
332 views

OpenLayers.Format.SLD - Ignores 'matchCase'?

I've trying to use OpenLayers to construct an SLD element to include in a WMS layer's parameters. This SLD document can contain a number of filters. This works fine and resultant SLD does work to ...
2
votes
2answers
235 views

Query/find features in ArcPad, hide the rest in map?

Trying to help out another department that does quarterly assessments of field data. Their symbology is all set by the status of the assessment (the only way I could figure out how to hide something ...
2
votes
1answer
93 views

How to use spatial filter in PyQGIS?

I have a buffer and need to filter a multipoint layer (QGSVectorLayer) so that I would get only features intersecting the buffer. What I've found: a) setFilterRect() This doesn't accept polygon ...
2
votes
1answer
43 views

Deleting only specific LiDAR points in QTM with Mensuration tool

I'm using Quick Terrain Modeler (QTM) 64-bit v8.0.3.4 - I have a set of LiDAR data that has some points that I want to delete, but due to their location it is hard (if not impossible) to delete them ...
2
votes
1answer
179 views

New filter expression QGIS 2.8

I try the new filter expression with QGIS 2.8. I want to filter only the selected objects on a layer in my map. My expression is: import processing from qgis.core import * vlayer = ...
2
votes
2answers
378 views

Las dataset to raster with ground points only

I'm trying to make a raster from a las dataset. I want to only use points classified as ground, but I can't figure out how to do this. What I've tried is: Create las dataset from 2 .las files. ...
2
votes
1answer
327 views

How to apply a filter to multiple vector layers in QGIS?

I am trying to apply an attribute filter to multiple layers in QGIS at once. The filter is to be applied to .osm data brought in through PostGIS to QGIS. I have tried selecting multiple layers -> ...
2
votes
1answer
211 views

Filter query error in QGIS2.4 or 2.6

I get this error when undertaking in query in QGIS2.4 or QGIS2.6: An error occurred when executing the query. The data provider said: OGR[3] error 1: Unrecognised field name ...
2
votes
1answer
306 views

PostGIS views vs WFS Filtering operations on PostGIS table

In what use cases should I prefer writing PostGIS views for filtering datasets versus filtering with WFS filter encoding operators and vice versa? In both cases I would be serving the data via ...
2
votes
1answer
376 views

How to set a spatial filter with Python/GDAL?

Is there a way with GDAL (Python) to set a spatial filter (bounding-box) on a raster before I process it? I want to read it as an array. BandReadAsArray(band, xoff=0, yoff=0, win_xsize=None, ...