Stack Overflow
Stack Overflow

Questions tagged [gis]

A Geographic Information System (GIS) captures, stores, analyzes, manages, and presents data that are linked to location(s). The GIS Stack Exchange should be considered for questions with this tag.

According to Wikipedia:

A geographic information system (GIS), geographical information system, or geospatial information system is any system that captures, stores, analyzes, manages, and presents data that are linked to location(s). In the simplest terms, GIS is the merging of cartography, statistical analysis, and database technology.

There is a Stack Exchange site devoted to Geographic Information Systems.

6555 questions
18
votes
3 answers

How to find intersecting geographies between two tables recursively

I'm running Postgres 9.6.1 and PostGIS 2.3.0 r15146 and have two tables. geographies may have 150,000,000 rows, paths may have 10,000,000 rows: CREATE TABLE paths (id uuid NOT NULL, path path NOT NULL, PRIMARY KEY (id)) CREATE TABLE geographies (id…
David Murdoch
  • 87,823
  • 39
  • 148
  • 191
18
votes
5 answers

Reading hdf files into R and converting them to geoTIFF rasters

I'm trying to read MODIS 17 data files into R, manipulate them (cropping etc.) and then save them as geoTIFF's. The data files come in .hdf format and there doesn't seem to be an easy way to read them into R. Compared to other topics there isn't a…
James
  • 1,164
  • 2
  • 15
  • 36
18
votes
10 answers

How to convert degree minute second to degree decimal

I receive the latitude and longitude from GPS with this format: Latitude : 78°55'44.29458"N I need convert this data to: latitude: 78.9288888889 I found this code here: link import re def dms2dd(degrees, minutes, seconds, direction): dd =…
bikuser
  • 2,013
  • 4
  • 33
  • 57
18
votes
6 answers

sql geography to dbgeography?

Maybe I'm missing something. I have a sql server column of the "Geography" datatype. I want to use the DbGeography type in my c# code. Any way to cast or convert from sql's geography to dbgeography?
Eric
  • 2,273
  • 2
  • 29
  • 44
18
votes
1 answer

How can I handle an "orphaned hole" in a polygon shapefile in R or ArcGIS?

I am trying to make a spatial overlay between two polygons ("grd" and "range") using the over function (rgeos). This code works for all files but one: range.grd.overlay <- grd[!is.na(over(grd, range)), ]@data$grdID # get gridcells that overlap with…
user1012744
  • 251
  • 2
  • 7
17
votes
2 answers

Does PostgreSQL implement Geospatial relationship queries?

My company is looking at different database providers, and how they implement Geospatial queries to get distances from a Lat/Long for a number of records. We are going to investigate PostgreSQL as a potential database platform. I've heard that…
pearcewg
  • 9,545
  • 21
  • 79
  • 125
17
votes
5 answers

How to make a CRAN package to download data only once regardless of OS?

The CRAN policy limits R package size to 5 Mb, which is little for graphical applications such as mapping. There are multiple ways of handling the package size limitations, all of which come with their drawbacks. The alternatives have been listed…
Mikko
  • 7,530
  • 8
  • 55
  • 92
17
votes
8 answers

Heightmap generation algorithm?

I was looking around the internet and couldn't find a perfect algorithm for this particular problem: Our customer have a set of points and weight data along with each point as can be demonstrated by this image: weighted points…
chakrit
  • 61,017
  • 25
  • 133
  • 162
17
votes
2 answers

Projection of a point to a line segment Python Shapely

I have a LineString defined by two points, so essentially a straight line segment, and I wanted to project a point on to it. I am aware of .project and .interpolate. However when the point is "outside" the segment, I don't want the closest point on…
sofaruntitled
  • 275
  • 1
  • 2
  • 6
17
votes
1 answer

Create a GeoDataFrame from a GeoJSON object

I have a Feature Collection of polygons and I have to first write it in a temporary file to then load it with geopandas.GeoDataFrame.from_file(tmp_json_file), is there any way to not write the temporary file and to just create the GeoDataFrame from…
kwn
  • 909
  • 2
  • 13
  • 25
17
votes
5 answers

Retrieving population density data

I need to figure out whether not a given location is considered urban or rural. I take it that the best way to do this is by looking at the population density of the city/state or province/country combination. The kicker is that we're using this for…
Tristan Crockett
  • 657
  • 6
  • 7
17
votes
9 answers

Where can I find the coordinates needed to draw the US in the Mercator projection?

So I'm writing a Javascript library that takes x,y coordinates and uses them to draw a map of the US. To do this, I need to find the coordinate data necessary to draw each state. This map on Wikipedia is a great example of what I need, because the…
Eli Courtwright
  • 186,300
  • 67
  • 213
  • 256
17
votes
3 answers

GeoJSON and MongoDB: Is it worth it to store points as GeoJSON.Point?

With the introduction of 2.3 > MongoDB has become even more useful with location data handling and querying. MongoDB stores documents as BSON, so each document with have all the document fields, which obviously potentially leads to larger databases…
nevi_me
  • 2,702
  • 4
  • 24
  • 37
17
votes
7 answers

Guidelines for GIS application development

I'm supposed to create a GIS application for my MSc, and I was wondering what are the best free and (preferably) open source technologies for development? What programming language to use for the development of such an application? Known choices…
Joksim
  • 179
  • 1
  • 3
17
votes
2 answers

How to project and resample a grid to match another grid with GDAL python?

Clarification: I somehow left out the key aspect: not using os.system or subprocess - just the python API. I'm trying to convert a section of a NOAA GTX offset grid for vertical datum transformations and not totally following how to do this in GDAL…
Kurt Schwehr
  • 2,638
  • 3
  • 24
  • 41
1 2 3
…
99 100