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Questions tagged [filter]

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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33 votes
2 answers
25k views

Filtering features in other layers of QGIS Atlas

I'm trying to use the QGIS Atlas tools to build student 'scattermaps', i.e. display the school and the students that attend that school, for 215 schools. The schools layer is the coverage layer, and ...
Inactivated Account's user avatar
7 votes
2 answers
4k 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 ...
Brian's user avatar
  • 4,229
16 votes
2 answers
55k 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 ...
dietmar's user avatar
  • 161
2 votes
2 answers
3k views

Using sieve filter in ERDAS Imagine and/or ArcGIS for Desktop?

Where can i use a sieve filter for my supervised classification? Can i do it in Erdas Imagine or in ArcGIS? I can't find it anywhere.
user28704's user avatar
11 votes
1 answer
2k views

QGIS query syntax differs between attribute table and feature filter

Using QGIS 2.16.2, I can successfully select records from a shapefile attribute table using the following expression: left("start_time", 10) = '2015-08-01' Please note that start_time is a string ...
Stu Smith's user avatar
  • 8,192
5 votes
1 answer
865 views

Selecting LiDAR return point type in LiDAR dataset with ArcPy?

I am trying to create a Digital Earth Model (DEM) using ArcPy under ArcGIS Pro 2, but I am running into some problems. I can generate a DEM within ArcGIS Pro by selecting only the ground points ...
user44796's user avatar
  • 1,925
28 votes
2 answers
24k views

What is the difference between != NULL and IS NOT NULL in QGIS filter expressions?

I have a shape layer with an attribute containing NULL values to which I would like to apply a filter for values different from NULL. Using the available GUI for such query construction, one would ...
Jochen Schwarze's user avatar
15 votes
1 answer
7k 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 -> ...
traffikHam's user avatar
5 votes
1 answer
12k 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 ...
andreash's user avatar
  • 741
18 votes
4 answers
19k views

Filter features based on their attributes using Python

How to get features by their attributes (similar to 'IQueryFilter' in ArcObjects) in QGIS using Python? Instead of getting all features and filter it manually, is there any option to use where clause ...
venkat's user avatar
  • 1,051
2 votes
1 answer
1k views

Showing only filtered features using Rule-based symbology in QGIS

I have a layer called 'A' with a field called "B", under this field, there are multiple values such as "C, D, E..." (one value for each row/feature in the attribute table). I have ...
TRE's user avatar
  • 61
13 votes
4 answers
7k 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 ...
vklopt's user avatar
  • 469
10 votes
1 answer
15k 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 ...
Jens's user avatar
  • 1,188
10 votes
2 answers
6k views

Filtering by geometry type in GeoPandas

I have a GeoPandas GeoDataFrame with a geometry column that contains both POLYGONs and MULTIPOLYGONs. How do I filter only MULTIPOLYGONs? I used this approach, but I am sure there might be better ones:...
baggiponte's user avatar
9 votes
1 answer
3k 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 ...
Nathan W's user avatar
  • 34.8k
6 votes
2 answers
3k views

Filtering layers by geometry type using PyQGIS

I need to list all layers with geometries skipping the layers without geometries. Can I be sure geometryType = 4 are geometryless? I cannot find the documentation explaining which number is which type ...
Bera's user avatar
  • 74.9k
4 votes
1 answer
554 views

Filter nearby points leaving only one in QGIS

I have a shapefile with points, however the algorithm gave not one point per location, but several. I would need to filter these points, so that there is only one point, does not matter which one, ...
g123456k's user avatar
  • 600
3 votes
1 answer
1k views

Adding spatial filter to WFS layer request not working

I'm trying to load big WFS layers to my project by mean of a Python script but since I only need to display features located in the south west of France I thought I could easily add a bbox filter in ...
wanderzen's user avatar
  • 2,140
3 votes
1 answer
3k views

DWithin WFS filter is not working

I'm new to GeoServer andI want to buffer an area around a point. I'm using a DWithin WFS filter but not getting any results. Please tell me the correct format to use DWithin. My GET request: http://...
user3266988's user avatar
2 votes
2 answers
6k 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 ...
Simon's user avatar
  • 1,207
2 votes
2 answers
5k views

LAS dataset to raster with ground points only [duplicate]

I'm trying to make a raster from an 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. ...
Johan's user avatar
  • 163
2 votes
1 answer
3k views

How to filter through geometry of feature collection instead of properties?

I have a FeatureCollection I made from a Polygon shapefile. I have fixed the geometries in qgis and should only be made out of many single polygons. But for some reasons some of my features are ...
B-C B.'s user avatar
  • 765
2 votes
1 answer
4k views

Passing selected polygon to INTERSECTS filter in a WFS request

In the code below, <ogc:Filter> <ogc:Intersects> <ogc:PropertyName>the_geom</ogc:PropertyName> <ogc:Function name="querySingle"> <ogc:...
okello's user avatar
  • 1,780
1 vote
2 answers
1k views

Avoiding NoData after Focal Statistics Majority

I am currently working with some classified land cover rasters (containing 8 land cover classes) in ArcMap 10.0. I would like to make them look smoother and have therefore used the Focal Statistics ...
user30508's user avatar
1 vote
1 answer
2k views

Keeping only ground points (class 2) with lasground in QGIS 2.14?

I want to keep only the LiDAR ground points in a las file, using the lasground tool from LAStools within QGIS. In QGIS Chugiak (2.4) there used to be an option to "keep class 2", but I don't know how ...
user66349's user avatar
  • 149
15 votes
2 answers
50k views

Filter a GeoPandas dataframe for points within a specific country

I have a dataframe of health survey data which is geotagged, called momdata. I have converted the dataframe to a GeoPandas dataframe, and used the geotags as the geometry column within the dataframe, ...
LucieCBurgess's user avatar
13 votes
1 answer
9k 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 ...
mrLite's user avatar
  • 399
13 votes
1 answer
8k views

Using IN-operator in query builder in QGIS

I want to filter out some bits of a layer and I want to do this in query builder in the on a text field which contains names of several countries. I cannot figure the use of IN as in I want to find '...
sjrichardson's user avatar
12 votes
2 answers
4k 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 ...
underdark's user avatar
  • 84.3k
11 votes
2 answers
10k views

How to use paging in a WFS query?

I am running a GetFeature request against a WFS server which does not support to download all data at once. Can I use ogc:PropertyIsGreaterThanOrEqualTo to split the dataset into chunks at download ...
JJD's user avatar
  • 1,511
9 votes
2 answers
2k views

QGIS using project variables in filter queries

In QGIS 2.14.11 LTR I have to apply the same (or similiar) filter query to various layers. I have the road name to filter for in a project variable and try to apply the following query: "road_name" = ...
Jochen Schwarze's user avatar
9 votes
1 answer
3k views

Filtering layers in QGIS atlas

In processing several spatial data sets (tbl_data_01, tbl_data_02, tbl_data_03, etc) using FME I establish a spatial table called "tbl_metadata" with information about each of the data set. This table ...
ragnvald's user avatar
  • 3,191
7 votes
3 answers
3k views

Limiting list values based on previous field in QGIS Forms?

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 ...
Jamie's user avatar
  • 591
7 votes
4 answers
2k views

Taking only the largest polygon from MultiPolygon layer in QGIS

I have MultiPolygon geometries in my file, and I want to take only the largest polygon within the MultiPolygon geometry to further work with it. I tried using the "Multipart to singleparts" ...
Anabella's user avatar
7 votes
4 answers
2k views

Can any WFS server accept ECQL filter as a POST request parameter

I believe GeoServer requires that filters passed in a WFS POST request are in the OGC XML based format. If you make a GetFeature request to GeoServer using a GET request the filter can be CQL or ...
Paul Wittle's user avatar
6 votes
2 answers
3k 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 ...
jan_b's user avatar
  • 792
6 votes
2 answers
7k views

Filtering a layer with attribute value from another layer in Qgis 2.18

I am pretty new to Qgis and a real beginner when it comes to working with expressions in Qgis. Maybe someone can help me with following problem: I have several Layers (like Building + House) and ...
lancelot1988's user avatar
6 votes
2 answers
714 views

Filtering QgsCheckableComboBox items in PyQGIS

I have a very long list of values and I would like to make things easier for the user by allowing to filter the items of the QgsCheckableCombobox with a lineEdit for instance. With this code I have ...
zakros's user avatar
  • 347
6 votes
1 answer
3k 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, ...
ustroetz's user avatar
  • 8,024
6 votes
4 answers
2k views

How to filter LiDAR data by scan angle?

I am looking to filter LiDAR data (.las format) by scan angle specifications (e.g. keep all points < 15). From a basic Google search, it appears that the libLAS library has the ability to filter by ...
Aaron's user avatar
  • 51.7k
6 votes
1 answer
3k 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 ...
bfishman's user avatar
  • 235
6 votes
1 answer
4k 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 ...
mac's user avatar
  • 163
5 votes
2 answers
902 views

Selecting features with equal values in different fields in QGIS

I don't know how to filter the attribute table in QGIS. I have two columns, "DN" and "DN_2", both with values from Corine Land Cover (111, 112, 223, etc). I try to select the rows ...
gis1234's user avatar
  • 319
4 votes
1 answer
5k views

QGIS Filter layer by expression [closed]

In PyQGIS, I am having difficulty using a filter expression on a feature layer. for feature in iter: name_dot = feature['name'] print name_dot expr = QgsExpression("\"name\"=...
Евгения Сидоренко's user avatar
4 votes
2 answers
1k views

Showing only features related to selected feature in another layer using QGIS

I have: ways (tracks) and points (way signs). The tracks are outgoing from the way signs. This should be the visible result: The ways with the name 'A' are visible (coloured) because the related way ...
MartinMap's user avatar
  • 8,338
4 votes
1 answer
6k views

Filtering Image in Google Earth Engine based on metadata

I'm trying to create a raster layer of the USDA NASS Cropland dataset using only certain crop classes. Is ee.Filter.inList only used for ImageCollections and not Images? It seems more appropriate to ...
dwolf's user avatar
  • 311
4 votes
2 answers
887 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, ...
guestagain's user avatar
4 votes
1 answer
669 views

Spatial queries with QGIS provider feature filter (layer filter)

QGIS offers the option to use layer filters: Layer Properties > Source > Provider Feature Filter, see documentation: Query Builder. As far as I can see, this filter is only able to filter based ...
Babel's user avatar
  • 73.2k
3 votes
0 answers
441 views

How to filter legend by map content in composer with raster layers?

Does the "Filter Legend by Map Content" button in composer of QGIs 3.2 version work only for vector layers? It seems it's a bug reported in 2.18.x version and should be fixed for 3.x versions (https://...
Fernando Franke's user avatar
3 votes
1 answer
900 views

Filtering (lasfilter on) huge LiDAR dataset

My dataset is about 8.3 GB after loaded into R environment by using lidR package. Some points which have return number greater than number of returns need to be removed. With a small dataset, I ...
wnursal's user avatar
  • 163