All Questions
888 questions
108
votes
16
answers
76k
views
Identifying Coordinate System of Shapefile when Unknown?
I have a Shapefile but its coordinate system is Unknown, and there is no *.prj file.
How can I identify it now?
124
votes
8
answers
370k
views
Calculating polygon areas in shapefile using QGIS
How do I calculate areas of an area shapefile in square meters (m²) or in acres (ha)?
I didn't find that functionality in the Vector Tools.
53
votes
3
answers
76k
views
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 >...
9
votes
2
answers
1k
views
Computing dominant area in polygon using ArcGIS Desktop?
First, I have a shapefile consisting of square grids and each grid has an ID. Second, I have a shapefile consisting of different zones (with IDs).
A grid ID in the first shapefile can contain many ...
116
votes
5
answers
302k
views
Merging multiple vector layers to one layer using QGIS
I've imported several shapefiles which where exported from a Mapinfo .tab. Several .tab-files are imported resulting in 20+ layers.
Afterwards I want to export it to GeoJSON; but I'm reluctant to ...
57
votes
5
answers
75k
views
Which character encoding is used by the DBF file in shapefiles?
Which character-encoding is used by the dbf-file in shapefiles? It seems it is handled different, based on the program and the local encoding-settings of the machine. Which encoding is 'right' - ...
25
votes
4
answers
130k
views
Changing projection of shapefile in QGIS
How do I change the projection of my shapefile using QGIS?
The default projection is set to EPSG:3003, I want to change it to WGS84 EPSG:32632. When I do a reprojection or I change projection in the ...
31
votes
8
answers
24k
views
Using ogr2ogr to convert all shapefiles in directory?
I have a directory with several shapefiles.
How can convert all these shapefiles to MapInfo with ogr2ogr?
I know how I can convert one file.
And I can make a batch script writing a line for each ...
15
votes
4
answers
10k
views
Setting default value for attributes in shapefiles using QGIS
In QGIS 2.14.6 I would like to define a default value for an attribute in a shapefile (or spatialite layer as well) which is applied if the user doesn't explicitly sets the value.
Is there a way to ...
22
votes
2
answers
41k
views
Adding shapefile or feature class as layer in ArcMap using ArcPy
I am trying to automate various tasks in ArcGIS Desktop (using ArcMap generally) with Python, and I keep needing a way to add a shapefile to the current map. (And then do stuff to it, but that's ...
11
votes
5
answers
21k
views
Clipping LAS data using shapefile polygons and open source software?
I am trying to clip or filter lidar files (.las, .xyz) using a shapefile that contains multiple polygons.
Is there open source software that can do this spatial operation?
My .las files are enormous,...
115
votes
23
answers
144k
views
Converting between KML and shapefile (SHP) format
My users are sending me point data that were digitized using Google Earth.
How can I convert their KML to a shapefile and vice versa?
39
votes
5
answers
80k
views
Writing Shapely geometries to shapefiles
Can someone demonstrate a simple way to write geometry data-structures from shapely into shapefiles?
I am particularly interested in polygons with holes and linestrings. It would also be beneficial to ...
34
votes
5
answers
13k
views
Bulk load multiple shapefiles into PostGIS
I've got over a hundred data layers in shapefile format that I want to upload into a PostGIS database. They are all in the same projection, but represent different data layers so they do not have the ...
50
votes
4
answers
65k
views
Joining non-spatial CSV file to spatial data (shapefile) using QGIS
I have a CSV file which has postcode data in a field, but it is non-spatial e.g. no Easting and Northing.
I have a shapefile with postcode in a field and some additional data.
I want to join the ...
40
votes
15
answers
121k
views
Converting MapInfo TAB and/or MIF to SHP using free tools or ArcGIS for Desktop core product?
How do I convert MapInfo TAB and/or MIF files to SHP using only free tools or ArcGIS itself?
I've not had much luck trying to do this in the past and I don't want to have to shell out for the ArcGIS ...
37
votes
6
answers
59k
views
Converting .shp into .gpx using QGIS
I would like to convert .shp into .gpx.
Using GIS, I open my shapefile and I tried to "save as" gpx but it gives an OGR error:
creation of field ObjectId failed (OGR error: Field of name '...
30
votes
6
answers
35k
views
Using ogr2ogr to convert GML to shapefile in Python?
I am trying to convert a GML to an ESRI shapefile using ogr2ogr utility in a python script.
I have successfully installed the GDAL/OGR package via osgeo but I am now struggling to find/understand ...
22
votes
3
answers
92k
views
Check if a point falls within a multipolygon with Python
I have tried several examples of code using libraries such as shapefile, fiona, and ogr to attempt to check whether a point (x, y) falls within the boundaries of a multipolygon created with ArcMap (...
18
votes
2
answers
16k
views
Computing parameters for QGIS Affine Transformation
I have a vector floorplan (DXF) that I've added to a blank project in QGIS using the Dxf2Shp Plugin.
I've been reading tutorials and StackExchange threads, but I can't seem to find out how to "...
9
votes
7
answers
25k
views
Fixing corrupt shapefile?
I have a shapefile that I was working on in ArcGIS Desktop 9.3 get corrupted somehow and it gives me the error "Number of shapes does not match the number of table records.". What I would want is to ...
33
votes
12
answers
63k
views
Converting shapefiles to text (ASCII) files? [duplicate]
How can I convert a shapefile (GIS) to text, or, how can I extract the information in a shapefile?
32
votes
3
answers
43k
views
How to encode shapefiles from LATIN1 to UTF-8?
Is there a way to encode shapefiles from LATIN1 to UTF-8?
17
votes
2
answers
5k
views
Ortho Projection produces artifacts
I`m trying to create a sphere-like view using qgis and the "world from space"-projection http://spatialreference.org/ref/sr-org/6980/ (essentialy an ortho-projection). ArcGIS wraps the shapes ...
6
votes
3
answers
7k
views
Joining table field with shapefile using PyQGIS
The following is currently unsuccessful at fulfilling a table field join to a point shapefile in QGIS.
All instances of the join object will print the proper values, and no error is flagged when ...
17
votes
2
answers
98k
views
Changing unit of measure from degrees to meters in QGIS?
I am running QGIS 1.7.0 on windows, and I donwloaded a shapefile of census block group boundaries from TIGER. This file appears to be in the WGS 84 coordinate system, and when I open it in QGIS the ...
8
votes
1
answer
636
views
Projection transformation of a shapefile
I am using QGIS 3.18.1.
I am working on a map around Alaska. I added a world basemap, then added DEM and finally drew a few polygon shapefiles on top.
I then tried to find a projection more ...
7
votes
1
answer
5k
views
Storing datetime values in Shapefiles using QGIS?
I have a shapefile with date in a string field. I create a new field with date type and use the calculator to make the conversion. But the result only provide the date part, the time part is removed. ...
4
votes
2
answers
14k
views
Intersect Shapefiles using Shapely
What I'd like to try and do is intersect some point buffers with census tracts, maintain their ID's and the tracts attributes.
I found a sample from http://www.macwright.org/2012/10/31/gis-with-...
61
votes
5
answers
48k
views
Bypassing 10 character limit of field name in shapefiles?
I'm exporting geometry with attached text attributes from oracle database to esri shapefile format (.shp) with Java and Geotools library.
Attribute columns in our database have names with more than ...
58
votes
6
answers
58k
views
Is there an automatic function in QGIS to package all files in a project for transferability?
In my project, I use a lot of geodata from different directories.
Now I want to give the QGIS project to a colleague (eg on a CD).
Is it possible to copy the shapes from different directories ...
43
votes
7
answers
39k
views
Choosing File Geodatabase (*.gdb), Personal Geodatabase (*.mdb) or shapefile format?
Previously, I have used geodatabases as an easy way to keep all files together rather than having dozens of shapefiles all over the place, and it is easier when finally exporting all the relevant data ...
29
votes
3
answers
106k
views
Cropping Shapefiles in QGIS?
I need to clip a large and very detailed shapefile in QGIS showing environmental data similar to a temperature map.
Is there something like the very simple crop tool like in Adobe Photoshop where ...
27
votes
9
answers
20k
views
How can I convert an excel file with x, y columns to a shapefile?
How can I convert an excel file with x, y columns to a point shapefile?
There are some somewhat optional requirements in addition to the correct creation of a shapefile:
Column types (as per Excel's ...
27
votes
1
answer
20k
views
Selecting features by attributes using ogr2ogr?
I am writing a shapefile after some processing; however, in the final step I need to do some selection by attributes from the the shapefile.
I am using the command in a shell with the aim of using it ...
19
votes
7
answers
27k
views
Changing order of features in shapefile [closed]
I have a shapefile and I want to change the order of the features.
Is that possible?
I want to sort the features in the shapefile because I'm embedding this shapefile in a mobile app. The app will ...
18
votes
4
answers
30k
views
Saving project with data source path as relative in QGIS?
Is there an option in QGIS to save the project with the data source being a relative path?
I don't see the option here. QGIS Wroclaw1.7.3
13
votes
2
answers
4k
views
Losing polygons after projecting map in QGIS
I'm fairly new at GIS, but I've run into a problem with a projection of a world map. I have a shapefile of all countries I downloaded from Natural Earth. After projecting it into a orthographic as ...
7
votes
1
answer
3k
views
Creating parallel line in ArcGIS Pro using ArcPy?
I want to create offset/parallel lines for my centre lines (over 12000 polylines) in different distance for each class number(i have numbers in column) and with the same line direction as centre line. ...
54
votes
2
answers
96k
views
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 ...
38
votes
10
answers
78k
views
Adding Attribute data to shapefile?
I can display a shapefile in openlayers but I need to add some attribute data.
I can open the dbf file in excel but there is no save as option in excel to the updated file as a dbf.
What is the ...
38
votes
4
answers
31k
views
Simple thematic mapping of shapefile using Python?
I wish to visualize geographical data in Python, without using ArcGIS/ArcPy, and make a map.
On the internet I found how to make a thematic map using Python:
Here is some code that I tried:
...
17
votes
1
answer
51k
views
Resizing shapefile features proportionally in QGIS
In QGIS (1.8.0-Lisboa) on Windows (OSGeo4W Install), how would you resize a feature proportionally?
The only way I've found to do this is by hand using either the Freehand Editing (0.2.6) plugin or ...
12
votes
5
answers
21k
views
Generating start and end points for LineStrings
I want to create start and endpoints in QGIS for a Linestring shapefile.
I tried using the "QChainage Plugin" but was not useful.
Can someone suggest a tool?
9
votes
3
answers
15k
views
How to read Greek fonts (ISO-8859-7) in shapefile attributes within QGIS 1.8.0?
I'd like to ask whether there is a way to read greek fonts in a shapefile's attribute table within QGIS 1.8.0.
1
vote
1
answer
2k
views
Reverse gdal_rasterize (-i option) does not work
When I use:
gdal_rasterize -b 1 -b 2 -b 3 -burn 255 -burn 255 -burn 255 polygon.shp tiff.tiff
I get a new tiff with a white hole in it with the shape of the polygon shp. However, when I use the ...
96
votes
5
answers
157k
views
Renaming attributes/fields in shapefile attribute table using QGIS
I would like to rename some fields in my attribute table:
Like rename "XRF_N3"in something else. It seems quite a easy issue but I don't find any information about how can I do that.
28
votes
5
answers
58k
views
Converting shapefiles to GeoJSON
I'm trying to convert shapefiles from the State of Texas Senate Districts website into a GeoJSON file for use with Google Maps API.
I'm using QGIS to facilitate but I can't get the projection/...
27
votes
2
answers
65k
views
Extracting intersection areas in R
I have two polygons. One contains fields(X,Y,Z) and the other contains soil types (A,B,C,D). I want to know what area of every field contains which type of soil. I tried the following:
library(rgdal)...
27
votes
5
answers
33k
views
Adding attribute field to existing Shapefile via Python without ArcGIS
I have a Python script that adds an attribute field to a Shapefile if doesn't exist. This is easy to do with ArcGIS (graphically or via Python), but I'm looking for something that doesn't depend on ...