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1500 questions
17
votes
1 answer
Clustering geographical data based on point location and associated point values
Given data points with longitude, latitude, and a third property value of this point. How can I cluster points into groups (geographical sub-regions) based on the property value? I searched by google and figured out that this problem seems to be…
Excalibur
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17
votes
6 answers
How to remove attribution in Leaflet?
I want to remove the "Leaflet.com" that appears on the right bottom of the screen
here. How can I do that?
Rabie Ben
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17
votes
1 answer
Monte Carlo simulation using QGIS and pgRouting on optimal sidewalk construction
I am new to spatial analysis and would appreciate some general direction on a project I am attempting, outlined below (I am starting from scratch).
GOAL: To find the best locations to install 2000 feet of sidewalks in my hometown in order to connect…
baha-kev
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17
votes
1 answer
Drivers of Fiona
What drivers does the python package fiona have?
When I check the manual it says [...] and the possible formats are enumerated in the fiona.drivers list.
However, when I type in python
from fiona import drivers
print drivers
>
four-eyes
- 3,378
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17
votes
2 answers
Automatically style raster using unique values in QGIS?
In ArcMap, it is possible to automatically calculate the unique values for a raster and then apply a different style to each unique value (see 1st image).
However, in QGIS, I have to manually add values for styling when using the "Singleband…
Peet Whittaker
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17
votes
3 answers
How to refresh the attribute table of a layer after editing the table in the DB-Manager?
Is there any way to refresh the attribute table of a layer after editing the table (e.g. add a column) in the DB-Manager?
Lunar Sea
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17
votes
2 answers
Do any Basketball Coaches use GIS?
The LA Times has a leaflet map viewer app showing all 30,699 shots in Kobe Bryant's career. It seems like spatial analysis could be useful for certain coaching decisions. Are any coaches actually using GIS tools?
Update2
LA Times wrote an article…
Kirk Kuykendall
- 25,787
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17
votes
6 answers
80% of data has a spatial component, says who?
This quote about how 80% of all data has a spatial component has been bandied around everywhere. Introduction to GIS classes, product descriptions, talks, etc. Would anybody know who first said it? Or A link to original article would be nice.
R.K.
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17
votes
1 answer
How to USE ST_difference AND ST_intersection in case of multipolygons? (PostGIS)
I'm trying to use ST_difference and ST_intersection with two layers of multipolygons.
I want something like:
With the input on the left and the result on the right.
MY DATA:
t1.geom contains 1000 differents polygons.
t2.geom contains 1000…
obchardon
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17
votes
3 answers
Is there a decent open source map-editor?
I would like to have an open source map editor for drawing a city map? I don't want to use OpenStreetMap. It will be a custom map project.
I don't need an advanced GIS system, but a simple map-editor, where I can use my own custom symbols. It must…
Jonas
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17
votes
4 answers
How to connect lines in a network?
I have a shapefile of lines and another of polygons. When two or more lines intersect a polygon they should be connected (snapped), but sometimes during manual digitization this doesn't occur. I need to find and correct all these errors. I used…
vascobnunes
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17
votes
3 answers
Calculating sum of parts of column based on another column using QGIS Field Calculator?
I would like to calculate the sum of values in one column, based on values in another column. To illustrate my question I uploaded the picture below. The second column consists of zipcodes, the third total sales. I would like to know what the total…
Ammar
- 171
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17
votes
5 answers
Simplifying polygons to linestring?
I would like to simplify some polygons that represent rivers into linestrings. I assume that holes in polygons can be omitted. Anybody has some good idea how to simply do it?
It would be nice, if it was possible to be done directly in postgis or by…
stachu
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17
votes
4 answers
How to add another layer to GeoPackage in QGIS?
QGIS 2.12 has support for saving a layer on the map in the GeoPackage format and that is great. However, I don't see a way to add another layer to the GPKG file, even though GeoPackage supports multiple layers. Is this functionality that is yet to…
Jim
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17
votes
7 answers
GIS for Local Police Department
I'm trying to recruit local police departments into a new GIS certificate that I am teaching in Florence South Carolina. None of the Police departments have any experience with GIS, but they are all interested in the technology.
I'm making an image…
Thad
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