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1500 questions
55
votes
3 answers
Smoothing polygons in contour map?
Here is a contour map for which all the polygons of levels are available.
Let ask how to smooth the polygons keeping all vertices preserved in their exact locations?
Indeed the contour is made on top of a grid data, you may suggest then to smooth…
Developer
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54
votes
4 answers
Making spatial view in PostGIS and adding it as layer in QGIS?
In PostGIS 2.0, I am seeking an efficient way to create a spatially enabled view that is viewable in QGIS.
I followed the context of Part 2 of @Mike Toews answer to How to create a table from existing tables (applying new schemas) in postgis DB?,…
RyanKDalton
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54
votes
2 answers
Understanding difference between Polygon and Multipolygon for shapefiles in QGIS?
Creating Scratch layer gives me a choice between Polygon and Multipolygon, so I started wondering how should I make use of them.
Reading a new book "Mastering QGIS" (through this answer by Joseph to What does buffer mean in QGIS Voronoi dialog?),…
Kazuhito
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53
votes
8 answers
Switching line direction in QGIS
I would like to be able to swap the direction of a polyline/line in QGIS. I made a custom tool to do this in MapInfo, however I can't seem to find anything for QGIS.
Does anyone know of a tool to do this?
Nathan W
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53
votes
13 answers
Seeking QGIS user interface tutorials and web resources
I wish to familiarize myself with the capabilities of QGIS up to and beyond QGIS version 3.0.
Can you recommend some good web resources and tutorials that would show me QGIS' capabilities?
I am interested in both using QGIS through its GUI and in…
jonatr
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53
votes
3 answers
Reprojecting vector layer in QGIS
I have a series of layers of lines (shapefiles) in My Project. The CRS of some are different and to merge them they all must have same CRS.
When I use Processing > Toolbox > Qgis_algorithims > Reproject_layer the reprojection only works if it is…
razi
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53
votes
3 answers
Meaning of Simplify's tolerance parameter
The standard parameters of Douglas-Peucker's simplify algorithm are geometry and tolerance (e.g ST_Simplify in PostGIS). What's the meaning of the tolerance parameter? I know that the bigger the value, the coarser the geometry will be. But does the…
ejel
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52
votes
8 answers
Using continuous color band for raster legend in QGIS composer legend?
I'm looking for a way to insert continuous colour legend for a raster layer.
I managed to create discrete symbols with values along the bar, but I would like to have a continuous bar with some values on the bar, similar to the old plugin "One-Band…
Bogdan
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52
votes
3 answers
Choosing between QGIS and GRASS for simple thematic maps with different layers
I was working with GIS and remote sensing in a university and professional environment some ten years ago (ArcInfo etc), so I have some experience even though somewhat outdated.
Now I am looking for an GIS application for a small farming project…
Alex
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52
votes
8 answers
Seeking administrative boundaries for various countries?
After learning about the US Census's TIGERLines datasets I've working with the following layers, from the USA data
Country boundaries
State boundaries
County boundaries
City boundaries
ZipCode/Postcode boundaries
What I am trying to find is the…
Pure.Krome
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52
votes
5 answers
How to calculate most efficient route passing through all the houses in the world?
I'm new to GIS.
I need some help in determining the best or most efficient route, using a flying sleigh, through all the houses in the world. One of my coworkers told me that this site would be the best place to ask, because I would find lots of…
Santa Claus
- 545
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52
votes
14 answers
Online WKT and GeoJSON viewer
I once found a great but simple webpage that has a drop-down with several text-based GIS formats such as GeoJSON and WKT, and a text box to copy/paste your data. The feature is then drawn on a world map. You can continue to add shapes on the same…
JPhi
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52
votes
4 answers
What is the going rate for GIS freelancers?
There appears to be very little information available about competitive hourly rates for GIS freelancers. Additionally, GIS freelancers never post rates on their websites. Upwork has some information on what people are asking, although I believe…
Aaron
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51
votes
5 answers
What raster smoothing/generalization tools are available?
I have a DEM that I would like to smooth or generalize to remove topographic extremes (chop off peaks and fill-in valleys). Ideally, I would also like to have control over the radius or level of "blurriness". In the end, I will need a set of rasters…
Mike T
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51
votes
4 answers
Where does QGIS write its error log messages?
I want to read and copypaste the error log for the crashes I am experiencing in QGIS 2.0. The error I am getting freezes QGIS so I have to ctrl-alt-del. I can see the last message in the panel, but can't copy it or scroll back to see the earlier…
IanS
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