All Questions
890 questions
26
votes
3
answers
35k
views
Order of polygon vertices in general GIS: clockwise or counterclockwise [closed]
Two days ago I asked a question about the internal storing order for the vertices of a polygon in ESRI shapefiles. That question was answered (Are polygons stored clockwise or counterclockwise in a ...
- 759
23
votes
6
answers
83k
views
Converting shapefile to CSV including attributes and geometry
I have a shapefile with 60k+ entries, all of which are polygons with corresponding attributes (acreage totals, landowner names, tax ID #s, etc.). What I ultimately need is a CSV file with all of ...
- 231
13
votes
1
answer
12k
views
Use python to add layers to TOC
I've been battling with adding layers to the TOC for some time now. I have managed to single layers added but need to loop through a folder and add all layers. Shapefiles I cannot get to add at all. ...
- 1,462
12
votes
3
answers
31k
views
Getting shapefile of river from OpenStreetMap?
I do not want to download the whole map of an area. I just want rivers and other waterbodies present in an area in shapefiles so that I can use them in QGIS. I tried geofabrik but it is giving whole ...
- 131
10
votes
5
answers
24k
views
How to display special German characters "ÄÜÖß" in a map?
I have a shapefile with names for Regions. These don't seem to contain special characters "Ä", "Ü", "Ö", "ß" but ugly hieroglyphs.
What can I do to display them correctly. If I import the shape as ...
- 2,331
32
votes
8
answers
29k
views
Getting list of distinct values from shapefile field using QGIS
I have a shapefile whose features I can filter by specifying a where clause in the query dialogue. F.x. I have a field named "city_name" and by stating "city_name" = 'London' in ...
- 550
29
votes
5
answers
36k
views
Converting image of map into vector format [closed]
What is the best way of converting a gif of a map into a vector format, such as a shapefile?
The only relevant parts that I am interested in are the outline of the island so I realize some manual ...
- 16.3k
22
votes
4
answers
58k
views
Loading .dbf file into QGIS
I want to use QGIS to extract lat/lng data from the vertices of polygons. There are about 400 polygons, each with maybe 200 vertices. I am having trouble with step one, getting the data into QGIS.
The ...
- 361
21
votes
1
answer
29k
views
Import a shapefile to postgis with ogr2ogr gives: Unable to open datasource
I want to use ogr2ogr in order to import a shapefile in a postgis database.
I have successfully installed ogr2ogr and I run from the pgsql the following command:
ogr2ogr -f "PostgreSQL" PG:"host=...
- 2,694
11
votes
5
answers
27k
views
Adding file name to attribute field using Calculate Field?
Does anybody know how to add the shapefile name to a field in the file's attribute table?
I've found a description:
'You have to use inline variable in CalculateField like %Name% in
expresssion ...
- 335
8
votes
1
answer
22k
views
Using Fiona to write a new shapefile from scratch
I am new to Fiona, and trying to wrap my head around reading a csv file and writing out an ESRI shapefile. I have most of it down, but am missing two things; (1) defining the projection/spatial ...
- 81
8
votes
3
answers
26k
views
Finding municipal-level administrative boundary data for India? [duplicate]
Does anyone know how to find a shapefile with boundaries of Indian municipalities?
I have tehsil boundaries as for year 2001, but I would like boundaries of municipalities and, ideally, also ...
- 237
7
votes
1
answer
24k
views
Assigning CRS to shapefile when it doesn't have one, in R?
I think that by using readOGR to import a shapefile renders worthless to put proj4string to the script since if any coords are available in the shapefile, it will be transported through the readOGR.
...
- 1,246
7
votes
3
answers
1k
views
QGIS Vector layer stretched across entire map
I've imported a vector layer with extents between two hemispheres near the antimeridian. Unfortunately, instead of having the geometry split in two, where one part lies east of the antimeridian, and ...
- 3,801
5
votes
4
answers
10k
views
Using PyShp to convert polygons in *.csv to *.shp files?
I'm converting csv data to shapefiles using the pyshp python library. What I want to do is very similar to Using pyshp to convert .csv file to .shp?, except that I don't know how to handle polygons.
...
- 151
75
votes
6
answers
286k
views
Opening shapefile in R?
I need to open a shapefile from ArcMap in R to use it for further geostatistical analysis. I've converted it into ASCII text file, but in R it is recognized as data.frame. Coordinates function doesn't ...
- 751
27
votes
6
answers
36k
views
Shapefile loader in pgAdmin 4
Recently I have updated my postgresql version. I have also upgraded pgAdmin from 3 to 4. But I was unable to load shapefile. I didn't find any plugin called shapefile loader. How can I get the ...
- 3,217
18
votes
3
answers
8k
views
Join CSV file to shapefile using gdal/ogr
I have a shapefile with several attributes, for example "YEAR", "COUNTY", and "AREA". I also have a CSV file with more fields that I want in the shapefile, such as "...
- 697
17
votes
3
answers
14k
views
Inverting Polygons using QGIS?
I have a Shapefile with Polygon features representing the world's land areas (continents, islands).
Is it possible to invert these, and get a geometry that represents the world's oceans and seas?
...
- 802
12
votes
1
answer
2k
views
Batch load multiple shapefiles to Postgis
According to the shp2pgsql help, the options drop, append, create and prepare are mutually exclusive. So, if I want to create a table from a shape and then append multiple other shapefiles, I do ...
- 13.7k
12
votes
1
answer
30k
views
How to import using shp2pgsql?
I want to import shapefile into PostGIS. There is one database postgres in it but no table added yet.
I am using this command:
shp2pgsql -I -s 4326 districts.shp districts | psql -d postgres -U ...
- 251
12
votes
2
answers
22k
views
Is there a way to export the style, along with a shapefile, to a kml in QGIS?
I see there were plugins in the past that may have done this such as qgis2kml and qgis2google, but they no longer exist.
- 723
10
votes
9
answers
72k
views
Exporting to DXF file from QGIS?
Is it possible to export labels based on Shapefile attributes into a DXF file?
I use QGIS 1.7.4.
I've been reading a CSV file and view it as a Shape Layer.
With the help of attributes from the File ...
- 117
10
votes
3
answers
3k
views
Can ogr2ogr "reverse clip" (or "clip out" or "erase" or "difference") one shapefile from another?
Is there a means in ogr2ogr to "clip out" one shapefile from another?
I know ogr2ogr -clipsrc B.shp out.shp A.shp will remove any part of A.shp that is NOT in B.shp.
Is there an ogr2ogr command to ...
- 201
10
votes
3
answers
22k
views
Using pyshp to convert .csv file to .shp?
I am trying to understand how I can use the csv module in python to open a csv file in the same folder as the python script, and then create a shapefile using the shapefile module pyshp.
The csv file ...
- 101
9
votes
7
answers
64k
views
Joining Excel table to shapefile in ArcMap?
I have a shapefile of lower layer super output areas (LSOA) for England and Wales and I have a spreadsheet of the indices of deprivation for each of the LSOA's in England. I want to join the ...
- 265
9
votes
1
answer
1k
views
How does shapefile 2GB limit equate to 70 million points?
Reading Geoprocessing considerations for shapefile output by Esri, it says that the 2GB limit translates roughly to 70 million Points.
When looking at the ESRI Shapefile Technical Description, the ...
- 426
7
votes
2
answers
28k
views
Convert shapely polygon coordinates
I am trying to work with a shapefile using shapely, fiona and python. The original coordinate system is in latitude and longitude that I am trying to convert to state plane system. So I want an ...
- 775
6
votes
1
answer
2k
views
Turning vector grid into individual shapefiles using QGIS?
I am using QGIS and I created a vector grid on a crop field in order to cut it into plots. I want to save each grid cell into individual polygon shapefiles automatically.
Here is an example of a ...
- 63
6
votes
2
answers
2k
views
Transform tif file to shapefile to get outer contour of area
I have the following .tif file of an area:
I want to make a shapefile out of the contour of the entire area, like the red line in the image below.
Is there a way to do this with QGIS?
I've tried ...
- 171
5
votes
1
answer
2k
views
Automating plan report generation using ArcGIS Desktop? [closed]
i have shapefile that contains a lot of parcels "parcel has like fields (n° parcelle,proprietaire, cin) see picture :
and i want for all parcels to generate this plan :
take a parcel and generate ...
- 645
4
votes
1
answer
3k
views
Clipping polygon precisely to raster (extent) using GDAL?
I need to clip a vector layer to the extent of a raster. It has to be very precise that's why I would not want to draw a polygon myself (and clip the two polygons). There seem to be some ways to clip ...
- 317
2
votes
1
answer
1k
views
Shapefile with no map and no attributes in QGIS
For QGIS 3.14 I was following the tutorials, and I got stuck in adding my very first new vector layer.
Every time I tried to do the option new Vector Layer, no map appears and the the attribute table ...
- 23
57
votes
3
answers
54k
views
How can I get a shapefile from a postgis query?
My data is in a PostGIS database. I would like to generate a shapefile from a query. How can I do that?
- 5,354
48
votes
3
answers
61k
views
Adding shapefiles to PostGIS database
I was able to create a Postgresql database and then I executed,
createlang plpgsql geospecies
psql -d geospecies -f postgis.sql
psql -d geospecies -f spatial_ref_sys.sql
So now can I directly import ...
- 4,415
27
votes
4
answers
38k
views
What is the difference between Coverage, Shapefiles and Geodatabases in ArcGIS?
I was wondering about the difference in spatial data storage methodology used by Coverages, Shapefiles and Geodatabases in ArcGIS. Coverage was the initial format, followed by Shape Files and now ...
- 595
26
votes
1
answer
25k
views
Merging adjacent polygons in shapefile that has been split at tile boundaries?
I'm currently using building data from the Ordnance Survey Vectormap District and I've noticed that a lot of building polygons are split in 2 because of the way the OS split up the shapefile.
This is ...
- 1,035
23
votes
7
answers
89k
views
Plot shapefile with matplotlib
I am trying to read a shapefile and plot it using matplotlib. Here is the code:
import matplotlib.pyplot as plt
import shapefile
shpFilePath = "D:\test.shp"
listx=[]
listy=[]
test = shapefile....
- 775
22
votes
2
answers
16k
views
Instantiating spatial polygon without using a shapefile in R
So, the usual way we read a shapefile in R is via the maptools package, like this:
sfdata <- readShapeSpatial("/path/to/my/shapefile.shp", proj4string=CRS("+proj=longlat"))
However, I have a use ...
- 493
22
votes
4
answers
32k
views
Exporting shapefile to PostGIS database in QGIS [closed]
How do I export a vector shapefile to PostGIS database? I am asking what format I have to export it.
- 1,462
21
votes
7
answers
18k
views
How to improve rendering performance of a very large shapefile?
I have a polygon shapefile that has a 100MB .dbf, and 500MB .shp file component. The reason it is so large, is that it is classified as a landbase for a whole district.
Everytime I view the file in ...
- 574
17
votes
2
answers
9k
views
Is there a standard for the specification of .prj files?
We use shape files for data exchange. I've looked at the .prj files: different programs produce different prj files.
Is there a standard how the parameters must be specified in a prj file?
AFAIK the ...
- 6,239
16
votes
7
answers
49k
views
Exporting attributes in KML file using QGIS
Here is what I am doing:
Create a layer by uploading a shapefile into QGIS
Select attributes of that file
Export selected attributes with the "save only selected features" check box when I save the ...
- 391
15
votes
5
answers
31k
views
Identify polygon containing point with R sf package
I would like to be able to map geocoded coordinates to a region on a .shp file in R using the sf package. I can load up the map and plot it but I am struggling with the code to return the region for ...
- 151
12
votes
2
answers
3k
views
Are mixed geometry types allowed in shapefiles?
Does the shapefile support mixed geometry types (ie. point and polygon all in the same file)?
- 177
12
votes
3
answers
51k
views
Connecting points by lines using QGIS?
I have a .shp file, where I want to connect all points (approx. 100) by lines.
I have a data field with the order (i.e. 1, 2, 3, ...).
I have tried PointConnector and Points2One, maybe I am using ...
- 121
11
votes
1
answer
28k
views
Exploding multipart polygons within shapefile in QGIS?
I've got a shapefile with polygons, some of which are multipart polygons. I need to create individual polygons out of the multipart polygons.
Is there a tool or plugin that can do this in QGIS 1.8?...
- 1,620
10
votes
2
answers
11k
views
Creating missing .shx file?
I am using ArcGIS Desktop to view one shapefile.
Only a select number of features are being displayed. The same number are showing in the attribute table even though the database file (.dbf) has a ...
- 187
10
votes
1
answer
5k
views
Polygon creation (Clockwise rotation or not) [duplicate]
According to "ESRI Shapefile Technical Description An ESRI White Paper—July 1998", Vertices for a single, ringed polygon are, therefore,always in clockwise order. Otherwise,"Dirty" polygons occur when ...
- 391
10
votes
1
answer
3k
views
Cleaning large Shapefile using v.clean in order to dissolve features?
I'm having real problems cleaning up and reducing the size of a Shapefile which is published by the UK's Environment Agency.
It shows the extents of the LiDAR open data they publish: each polygon is ...
- 305