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Questions tagged [qgis]

QGIS is a cross-platform GIS application licensed under the GNU General Public License.

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How to convert multiple shapefiles of different geometries into a georeferenced raster

I have multiple shapefiles extracted from OSM vector data, as shown in the image bellow: I want to save them into a raster file with a black background. Is there a way to do that using QGIS or ...
1
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1answer
12 views

Clip Vector by Custom Raster Extent

I have a raster image (elevation map from DEM) where I have limited the rendered elevation to only 3,500' and higher. I would like to convert the boundary/extent of this rendered image into a vector ...
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0answers
7 views

QGIS install on OSX with homebrew: “You have other linked versions!”

I have an OSX Mojave setup where I've already installed PostGIS and GDAL using Homebrew. Now I'd like to install QGIS. I'm trying: brew install qgis But... I'm getting lots of warnings of the form: ...
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0answers
8 views

Installing QGIS on OSX: “QGIS requires Python 3.6” but 3.6 is already default Python

I'm trying to install QGIS on OSX Mojave from the official installer. I have system Python 3.6 installed, as the default: $ which python $ ls -al /usr/local/bin/python lrwxr-xr-x 1 me admin 44 18 ...
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0answers
8 views

Kernel Density Estimation Weighting Factor

I dont understand where is this weighting factor coming from, does it need to be in the quakeLyr in the attribute table named with "mag" or? ##Now, we can run the kernel density estimation algorithm ...
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0answers
15 views

SDO Oracle Table not recognized as Geometry in QGIS

I can connect to the Oracle Database with QGIS but spatial table/layers are not recognized as such. I have read the following in the QGIS documentation: Normally, an Oracle Spatial layer is ...
1
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0answers
21 views

Changing the field colour/design on a QGIS 3 QT attribute form?

I have problems with changing the physical appearance of a custom attribute form (QGIS 3, Windows 7). A custom attribute form can be designed, for use in QGIS, using QT / QT Designer. In QT Designer ...
3
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0answers
31 views

Cheapest path through polygons and lines from point to point

I want to find the cheapest path or the least cost path from one point to another point. The points are part of a vector map and do not lie on a network. All features being part of the map have ...
2
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1answer
24 views

Central deployment of startup.py in QGIS

In QGIS 3 on Win10 we use a startup.py script for setting up e.g. database connections and a couple of other things, residing in C:\Users\me\AppData\Roaming\QGIS\QGIS3 What we are after is to ...
2
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1answer
37 views

Get OGR driver Name for QGIS VectorLayer

Is it possible in the Python script to get the name of the OGR driver (for example, "Esri Shapefile" or "MapInfo File") for the QGIS vector layer? __ QGIS 2.18
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2answers
136 views

Apply Line Pattern Fill to LineStrings?

I am trying to print out a network map using black/white hatching patterns, similar to Black/white hatching pattern fills in QGis but for Lines. Is there some trick I can use?
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0answers
10 views

XML to TIFF raster and zonal statistics in QGIS

I was sent several XML files of a flood model's peak extent that works fine in ArcGIS, I need to use zonal statistics, and I don't have that available in my workplace's ArcGIS subscription, so I need ...
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0answers
9 views

Cannot find Grass7 folder in QGIS 2.18 content folder

I have freshly re-installed QGIS 2.18.28 in the prescribed order. I was under the impression Grass7 in included in one of the install packages. But when trying to point QGIS to the grass7 folder under ...
1
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0answers
36 views

Raster Volume Returning Wrong Volume

I have a clipped surface using Washington State Plane North (feet) added to a QGIS project using the same CRS. I am trying to calculate the area under this surface (a dirt pile) using SAGA Raster ...
1
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1answer
30 views

How to split vector layer in PostgreSQL/PostGIS

QGIS has this nice tool to Split a layer into multiple layers based on one attribute and create a new layer for each unique value within that attribute. Is this also possible using PostgreSQL/PostGIS?...
1
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1answer
27 views

Error after loading new plugin Qgis 3.4

In Qgis 3.4, after creating a plugin with plugin builder, compiling it with pb_tools, I still can't load it to Qgis. I keep getting the following error message: "Couldn't load plugin 'test_api' due ...
0
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1answer
23 views

Installation of QGIS 3.4.4 on Ubuntu 16.04 fails to install qgis-plugin-grass because of uninstallable grass760 dependency

I have used the instructions here marked Tested 29/06/2018 to install QGIS 3.4.4 on Ubuntu 16.04. While QGIS installs nicely I get an error on installing qgis-plugin-grass. Subsequently the Grass ...
2
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1answer
21 views

Isolating and exporting specific sections of a shapefile in QGIS?

If I have a shapefile layer in QGIS showing the spatial boundaries of subsections of a larger area (e.g. counties within a state, or countries within a continent), how would I selectively crop out one ...
2
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0answers
23 views

Displaying Legend for Variable Width Line in QGIS

I am using QGIS v3.4 to display a simple line as a line of varying width using the variable line width attribute facility of QGIS (please see screenshot below). The layer displays correctly within ...
2
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0answers
15 views

QGIS globe map - label distortion [duplicate]

I have created an azimuth orthographic projection map (basically a globe, I've used this custom CRS: +proj=ortho +lat_0=51.470129 +lon_0=-0.452751 +x_0=0 +y_0=0 +a=6371000 +b=6371000 +units=m +no_defs ...
2
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1answer
29 views

QGIS Table Manager

in QGIS 2.18 I used the table manager plugin for renaming or removing columns in a table. This plugin doesn´t exist in QGIS 3.4.1. Is there any other plugin or way to rename,remove or order columns in ...
3
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1answer
31 views

QGIS print composer - Legend columns not aligning when title is deleted

I want a simple legend without a title and with 2 items side by side. I can't find an option to turn the legend off so have just deleted text from the Legend title box. I select Columns (2) - Equal ...
2
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1answer
74 views

Equal values attribute table

I don't know how to filter the attribute table in qgis. I have 2 columns, DN and DN_1, both with values from Corine Land Cover (111,112, 223, etc). I try to select the rows that have the same value. ...
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0answers
22 views

Moving .pdf as a raster freely without referencing

If I import a .pdf as a new raster layer, but the referencing is off. Is there a tool in QGIS to grab and hold on to the pdf so i can move it freely to my desired location without having to worry ...
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0answers
45 views

Reporting distances to polygon features along river network using QGIS?

I am using QGIS 3.6 on windows 10. I am trying to work out a way of reporting on the distances to polygon features (ecological sites) located along a river network. I have extracted the shortest path ...
2
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0answers
29 views

“slyr-master” plugin for QGIS doesn't work due to “missing meta data”

I downloaded the "slyr" plugin from GitHub which should be able to convert .style data into QGIS. According to the README file, I'm just supposed to add the "slyr" folder to the Python -> Plugin ...
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0answers
30 views

Producing georeferenced raster to open in Google Earth? [on hold]

I'm new to QGIS. How do I georeference a cadastral image from PDF or TIFF, and open it already positioned in Google Earth?
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0answers
37 views

Reprojection puzzle

Initially, my question was about strange results in area calculations in QGIS. I got bigger results for planimetric calculations - using area($geometry) - compared to ellipsoidal calculations - using $...
1
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0answers
18 views

Error installing visibility analysis plugin

When I try to download and install the latest version of the visibility analysis plugin from both https://plugins.qgis.org/plugins/ViewshedAnalysis/ and http://www.zoran-cuckovic.from.hr/QGIS-...
1
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2answers
41 views

Selecting highest value within group using QGIS?

I have a .shp of points. This points are organized in groups with same ID (group 1, 2 ,3) Each group has 10 points. Each point has a Z column with Z values. I want to select the point with the ...
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0answers
20 views

QGIS Authentication

I have been doing some reading regarding QGIS authentication. Like most of the threads I have read, I am getting a barrage of authentication requests when someone opens someone else's QGIS project ...
3
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1answer
26 views

Creating custom CRS from existing CRS EPSG:22780?

I am currently trying to figure out how to create a custom CRS in QGIS based on Deir ez Zor / Levant Stereographic (EPSG:22780). For this I am working with a map which shows both the EPSG:22780 ...
1
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1answer
36 views

Creating boundaries from points and area measurements

I have a list of villages and the area measurement for each village. Is there a way to draw hypothetical boundaries of each village based on the area measurements and the calculation is able to ...
1
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0answers
14 views

gdal_merge novalue

I managed to run gdal_merge for multiple geotiles (jpeg). I am using the following options: command = "gdal_merge.py -init 0 -a_nodata 0 -co COMPRESS=LZW -co BIGTIFF=YES -o "+out_bez+" -of gtiff " +...
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0answers
28 views

another layer dependent field values in QGIS [on hold]

Could you please help me in achieving automation written in point no 5 of this query. Query in QGIS
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1answer
24 views

Dissolve with common value in a field and not common in another

I have a shapefile in QGIS and I want to dissolve it with the options: A field named 'specialid' has the same value A field named 'city' has different value Ok the first is very easy. It is ...
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0answers
15 views

SUMO Network to QGIS

I'm trying to import an XML network into QGIS which I got from using SUMO's OSM Web Wizard tool. The process that I'm looking to follow is documented here under the "(Q)GIS" section. The following ...
0
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1answer
28 views

Reading NV chart data (.bsb and .eap) with QGIS?

I have some data from NV charts. As it looks like the data is contained in .bsb and .eap files. Is there a possibility to implement these data in QGIS as raster as a background? Loading the .bsb data ...
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0answers
32 views

Create mask layer from paletted raster

I have QGIS 2.18. I have the ground truth of land type for France. That is a paletted raster (i think.. i'm new and maybe it is not the correct word) I loaded a style.qml file for this raster and I ...
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0answers
16 views

Convert Raster to grid in order to open it in Excel

I have 2 raster files and I want to nalyse the correlation between values in the two layers , So I want to convert raster files to grids/arrays so as to run an analytical algorithm on them like PCA ...
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0answers
17 views

Clipping raster to fit smaller one using QGIS? [duplicate]

I have a classificaton map of the France vegetation and i want to clip it to fit with my Sentinel-2 tile. How can I do that with QGIS?
1
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1answer
45 views

Automatic sheet size in text label in QGIS

I'm in Print Composer and want to develop a template. In that template, I would like to add a text Label which automatically represents the size of the sheet in the format "Sheet size: 841x1189". ...
0
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0answers
17 views

Loop a group of layers and keep another layer on

While using loop visible layer plugin, it simply makes a loop of a predefined group of layers, rest of the layers are turned off. What I want is to keep a vector layer on and visible all the time ...
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0answers
16 views

QGIS to .DXF export: labels do not appear

I have been trying to export a shp layer in QGIS 2.18 to dxf with some labels using the export to DXF tool included in QGIS, but somehow, the labels won't appear on the export. I have tried changing ...
4
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3answers
296 views

Identifying polygons that intersect with another layer using QGIS?

Using QGIS, I have two polygon layers, a vegetation layer and a treatment layer. I want to add a field to the attribute layer of the vegetation layer to indicate if any part of the polygon has been ...
2
votes
1answer
53 views

Using QGIS to make changes to OpenStreetMap?

I want to be able to use a familiar editor (QGIS) to save building footprints to OpenStreetMap as I edit them. I have been building a layer in QGIS and marking the polygons that need to be uploaded. ...
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1answer
16 views

Coverage ( MultiPolygon) of Linear Assets (MultiLine String)

I am investigating the radio coverage on the number of linear assets. The coverage is in the form of Multipolygons showing bands of Predicted RX Signal strength in the area of concern. The linear ...
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0answers
28 views

String to integer [on hold]

I am trying to convert string to integer for raster conversion. I have been doing this successfully with the Refactor tool, however I am stuck on a particular layer. Every time I try the same method ...
1
vote
1answer
25 views

Calculating area difference between two polygon shapefiles using QGIS

I have two polygon shapefiles which contain about 30 features. These features have different boundaries in both shapefiles so the areas are different too. I want to calculate that difference in the ...
0
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1answer
29 views

Exporting data to a text file using a template

I've build a toolbox in my project environment to plan "Aids to Navigation". The vessel (ship) that does the actual work in the field has a navigation computer that can only import waypoint. These ...