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Questions tagged [qgis]

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

1
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0answers
24 views

Errors while viewshed analysis in QGIS

I want to analyze viewshed from some point. For that, I installed the viewshed plugin, and run it. elevation raster: dem observation points: observer(only one point) But it just shows the message "...
-4
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0answers
31 views

Difference between definitions “feature” vs. “layer” [duplicate]

What is the difference between the two definitions "feature" vs "layer" by means of GIS? Especially in QGIS (PyQGIS) is there any difference to say "feature" or "layer"? For example, I have the ...
3
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0answers
40 views

Updating shared custom functions / expression code in QGIS

All the QGIS documentation I've seen on custom functions (used in expressions) says that the code is saved in the user's local expressions directory, e.g. ~/.local/share/QGIS/QGIS3/profiles/default/...
3
votes
1answer
62 views

Counting number of roads between two points using QGIS

I use QGIS 2.18 and I have a point shapefile of many animal locations and a shapefile of roads. I want to use QGIS to tell me how many roads are between each pair of animal locations. So, basically ...
3
votes
1answer
72 views

Fill color and outline color with the same value [duplicate]

I made a categorized symbology on a shapefile, but the color value of outline (stroke color) is different than the color of fill color option. How can I ensure that both colors are the same for fill ...
0
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0answers
25 views

QGIS: How to set coordinate unit using google satellite xyz-Tile?

I'd be glad if someone can help me with this. So, what I want to do is quite basic: Digitalizing shapes with google satellite image using QGIS. For that I am using the Google satellite-xyz-Tile. ...
0
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1answer
19 views

Loading *.mrr files in QGIS or using GDAL

Does anyone know how to load the new proprietary MRR files using QGIS or GDAL? I tried using Add Vector Layer but QGIS did not recognize this file.
0
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0answers
53 views

Extent of shapefile in meters instead of decimal degrees QGIS

i'd be thankful for your help. My QGIS-project has the CRS WGS 84 EPSG 4326 and so does the shapefile I created. The coordinates on the edge of the window however shows, I think, meters, although I ...
1
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0answers
27 views

Create a Non-North/Rotated-Vertically User Coordinate System?

I need to plot 3d PostGIS data into vertical planes for symbolization and drawing vertical cross-section interpretations for mineral exploration models. I have written a short plpgsql function that ...
1
vote
1answer
31 views

adding dialog plugin qgis2web

I have exported my webmap using qgis2web and while playing with it, I was able to change the settings of the items already present on the map (for example position, language, zoom levels, etc.) ...
1
vote
1answer
50 views

Digitise a circle around a point in QGIS 3?

In previous versions of QGIS I used the Intersect It plugin for drawing circles around a point with a specified radius. However, I cannot see a way to digitise a circle around a point in QGIS 3. I ...
1
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0answers
14 views

zoomScale() doesn't work in QGIS 2.14 standalone c++ application

Can't set scale for my canvas with mapCanvas.zoomScale(50000); Seems like canvas is zooming to 1:1 and for a few seconds I can't zoom in or zoom out with mouse wheel. Any suggestions?
2
votes
2answers
166 views

Starting a QGIS project for a fantasy world map from raster images

I want to use QGIS to georeference two fantasy (D&D) raster maps, one is the map for the entire world (Toril), one is the map for one of the continents (Faerun). This is the post with the world ...
0
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0answers
13 views

How to use QT signals and slots in QGIS C++ API

I'm developing a standalone QT 5.11.2 application using QGIS 3.6 C++ API. I have defined a slot that is meant to consume a currentLayerChanged(QgsMapLayer * layer) signal. The slot declaration in ...
1
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0answers
22 views

Checking for exact value in QGIS raster calculator

I would like to single out values which are equal to a certain floating point value using QGIS raster calculator. I tried to run the following: "Converted@1"==-3.40282347*10^38 But I got the error ...
0
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0answers
15 views

Compass direction from single PDa point to multiple

I have found the distance matrix tool to provide the distance from a single point to multiple points. However, it would be useful to find a tool to automatically calculate the compass direction of the ...
1
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0answers
20 views

Split raster to many irregular polygons [closed]

I'm splitting a national soils raster file into regional (county) rasters, and organizing the soils classifications into a database keyed by region, eventually plot- or farm-level detail. At the ...
1
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1answer
40 views

Which coordinate system/ projection would you use to measure lines globally distributed?

Which geographic coordinate system /projection would you recommend to measure the length of hundreds of lines which are globally distributed (southern and northern hemisphere)? The lines have a length ...
1
vote
1answer
33 views

Calculate geographic location of point display offset in QGIS

I have a point layer in which some symbols are displayed offset from the feature's true location by a given number of millimetres. As the map's zoom changes the offset symbol's geographic location ...
2
votes
1answer
26 views

About the method of resize raster resolution

I opened a raster file as a layer, and click the right mouse button and select "Save as..." to change the resolution. I got the new raster, but I want to know what is the method (average, aggregation.....
1
vote
2answers
46 views

Calculate the percentage of a Line passing through Polygons

I have a polygon layer of a region (100% coverage, no overlaps) and a line layer in the same region. I want to calculate for each line to which percentage it crosses certain polygons. I have seen ...
1
vote
1answer
30 views

Rasterize point layer with weighted distance

I have a point layer representing wells in a region. i am able to rasterize it and write the well density into the raster as integer, so far so good. What I aim for is to create a raster with values ...
0
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0answers
38 views

File SHP needing to be shifted up?

I am new in GIS. I am trying to use the curves of level (downloaded from this site in SHP format) to use them into Tableau Desktop. The problem is that if I loaded the lines, they are not ...
0
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0answers
31 views

Finding clusters of non-adjacent parcels greater than 'x' hectares [closed]

Background: I have a number of land parcels with "Parcel_ID" and "Area". They are separated from each other by great distances (km's) or short distances (5m), forming 'clusters' on the landscape. In ...
1
vote
1answer
27 views

Extracting vector/raster data for CSV data points [closed]

I am using QGIS and I have a CSV file of lat and long coordinates which represents presence points of a species in the USA. I also have vector (the state extents/names) as well as raster information (...
1
vote
2answers
46 views

Creating shapefile using QGIS?

I start with Create New Shapefile Layer, I give it a name and then select Polygon. I then create my Polygon shape, its all good to this point. I now show a polygon with an outline and light red fill. ...
3
votes
2answers
60 views

QGIS SAGA functions failing “… following layers not correctly generated. …” [on hold]

I've been having an issue with the SAGA functions for a while now, I believe since upgrading to one of the early 3.x versions. No matter which function I use they all fail with the same error (...
2
votes
0answers
32 views

Visualizing 3D focal mechanism (beach ball) in QGIS

Currently, the qgis2threejs plug-in in QGIS allows users to use a 3d model as symbology for point vector data. I made a 3d focal mechanism template (beach ball) and used it in qgis2threejs: You can ...
0
votes
0answers
33 views

Extract point data to polygon features [duplicate]

I am trying to import data from a point that lies on a certain polygon feature (or raster). As an output I would like the polygon feature to have the point data as a new field in the attribute table. ...
0
votes
1answer
28 views

How do I make a map's background transparent in a layout?

I am trying to add an overview map to my layout. The main map is projected while the overview map is a 'globe' (image below). I want to make the white part of the overview map transparent. I have ...
1
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0answers
31 views

Clipping ocean water shapefile in QGIS [closed]

My requirement is to find a reliable source of Ocean water shapefiles, this is because OSM or Geofabrik does not provide this information. I eventually landed on this page: https://www....
0
votes
0answers
18 views

QGIS Heat Map output not correct

Fairly new to QGIS here. I'm having trouble creating a heat map in QGIS3 from a set of points. I've followed what others have done online (e.g.: https://www.youtube.com/watch?v=o9Gqrr5cYrY) but in my ...
0
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0answers
27 views

QGIS Process Modeller Multiple Input (3.4.4)

I am trying to build a process with the process modeler. The process is working with one shapefile via Input vectorlayer. But in the final Version the model should do a Folder or Muliple Input. But ...
0
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0answers
18 views

QGIS Time Manger is displaying events at the same time on different days together

I've got a dataset that has time like below... I have set the plugin to use %d/%m/%Y %H:%M:%S But it is showing events at the same time on different dates together. How can I get it to step through ...
1
vote
1answer
43 views

Make lines from points in Geometry Generator

I have a data set with a large number of start and end positions. I am trying to generate lines between start and end positions using the Geometry Generator but it does not work. I get no errors ...
1
vote
1answer
54 views

Creating Bivariate choropleth map a.k.a. Relationship map in QGIS [duplicate]

There is one polygon layer with the number of "immigrants" and "emigrants" respectively. I want to visualize those two values together. Diagram with both normalized values is not an option because the ...
2
votes
2answers
63 views

Measuring length of edge of polygon

I have a layer of polygons, cadastrals, that i'd like to have the length of the edge of: I thought about doing this: Dissolve the polygons Create one large dissolved polygon Making a; From polygon ...
0
votes
0answers
15 views

Load imagery layer on the top of a morton tile through geometry?

tile_col = self.current_tile[0].split("-")[0] tile_row = self.current_tile[0].split("-")[1] tile_matrix = self.current_tile[0].split("-")[2] try: space = "%20" url = "http://...
3
votes
1answer
94 views

Setting correct UTM zone

I am using QGIS for mapping a series of buildings, I got the UTM coordinates from Google Maps and imported them as a delimited text layer. However when I search for the UTM Zone that I need it doesn'...
0
votes
0answers
26 views

Interpolate 3D raster with Anisotropy

I am building a 3D geological model for soil deposits. I have two approaches to build a 3D raster. My dataset is about 300k points of bh information with texture and permeability at every meter ...
0
votes
2answers
46 views

Pixel depth and raster output won't align with the original

The problem Need to convert a raster .tif tile (DOWNLOAD) from WGS84 to GDA94 Albers; Need to convert its stored pixel info from Float32 to 8 bit UNSIGNED; Need Compression set to "NONE"; Need to ...
0
votes
1answer
26 views

ECW not reocgnized as supported file format in GDAL operation

I've installed QGIS 3.6 for MAC, with GDAL 2.4, ECW GDAL Plugin for GDAL 2.4, and manually installed the libraries from ERDAS ECWJP2SDK 5.4. This allows me to insert ECW files as raster layers in ...
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votes
0answers
28 views

Clipping raster to vector polygon

I have a raster file containing landcover classes of the UK. When I clip it to my Derbyshire Dales vector file it comes out as just a black screen with values of 0 and I can no longer see all the ...
1
vote
1answer
54 views

QGIS 3 Processing Script refer to input layer

I'm new to Python and trying to figure out how to write my first Processing Script using QGIS 3.6 on Windows 10. I'm using the default template provided in QGIS 3 (Toolbox > New script from template)....
1
vote
1answer
61 views

Generating map tiles with QGIS 3.6?

Similar to this rather dated question, is there a way to generate map tiles on QGIS 3.6? The plugins linked from that question only support QGIS 2.x. I wonder if things have changed in QGIS 3.x ...
1
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1answer
63 views

Can ArcMap open shapefiles made by QGIS?

I have created many EPSG shapefiles in QGIS and would like to import them into ArcMap for analyzing. Can ArcMap open shapefiles made using QGIS?
0
votes
2answers
36 views

Get shapefile from ArcGIS online for QGIS

How do I download shapefile information from ArcGIS online and access it in QGIS. An example shapefile that I would like to obtain is linked below: https://morgancountyco.maps.arcgis.com/apps/...
1
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0answers
23 views

How can I summarize the values of a raster to make a clear legend? [closed]

I produced a relief map out of a ASTER Satellite Picture by using a colour ramp (Symbology -> band rendering). I want to make a map out of that in the Print Composer but the Legend is very confusing ...
0
votes
1answer
20 views

Can I import raster files from GRASS GIS in QGIS versions later than 1.8.0

I have a process that I have used for years where I create .ascii files with a Python process, import them to GRASS GIS 6.4.3 and do some raster calculations (r.mapcalc). This works great but then ...
0
votes
0answers
31 views

QGIS returning incorrect area as derived property [closed]

I'm getting huge errors on the derived property of Area. I've checked that all my layers are using the same projection, WGS84. Using the area measurement tool gives accurate results, using the ...