Questions tagged [shapefile]

A vector data storage format for storing the location, shape, and attributes of geographic features. Often referred to as 'an ESRI shapefile', as ESRI developed it.

Filter by
Sorted by
Tagged with
4
votes
2answers
8k views

Selecting features of vector layers based on another vector layer using QGIS?

I am using QGIS 2.12.2. I am using three vector layers (point, polyline and polygon shapefiles) of the region of interest. Any advice in making the selections from one dataset based on the other ...
3
votes
2answers
2k views

Converting from shapefile or raster formats to LAS? [closed]

I am looking for a solution to convert either from ESRI shapefile format to LAS or from a common raster format to LAS. I have access to following software: ArcGIS 10.2 for Desktop (arcinfo with ...
2
votes
2answers
488 views

“Phantom” features showing up in QGIS?

I am using QGIS 2.4 on Windows 8.1. I have a project in which I have been digitizing from OpenMaps. Last night I was doing some more digitizing, saved, and closed the program. When I opened it this ...
2
votes
1answer
212 views

Joining 2 layers by location doesn't join desired fields from attributes tables

I have 2 layers that I'm trying to join by location: 1 is a point layer (CRS 4326) and the other is a shapefile layer (CRS 4326). The shapefile layer has a field in the attribute table whose values I ...
2
votes
3answers
2k views

“Clip” hole into Shapefile

I want to clip a hole into a shapefile. The underlaying shapefile (greenish) consists of many polygons. The overlaying (red) is only one polygon. When I use the clip tool I get this or this ...
2
votes
3answers
4k views

Storing two kinds of point geometry in shapefile or creating multipoint shapefiles? [closed]

Following How many interior and exterior rings can a polygon have in a standard ArcGIS shapefile?, can I have a mixture of two kinds of geometry in a shapefile of type point. Just like I have about ...
1
vote
1answer
192 views

Shapefiles rewritten to 100 bytes

When you run QGIS and open a project file (.qgs), a new version of QGIS will read the .shp files and update them for format changes that go with the new version. The changes finish, but don't work, ...
1
vote
1answer
3k views

How to have a nullable field included in a shapefile using the Geotools library?

I am trying to add a new field to a shapefile and need it to store null values. But by using SimpleFeatureTypeBuilder from the Geotools library and then using the Add command, it is not giving the ...
1
vote
2answers
2k views

Vertical lines in a polygon shapefile

I am working with a GIS problem using a single input of a polygon shapefile. Consider an irregular polygon. I want to draw vertical lines across the extent of the polygon at equal spacing. How I ...
1
vote
2answers
968 views

QGIS rounds up the coordinates to six decimals when saving layer changes

I have the problem that when I create a new point (in a point layer) or a new line (in a line layer of course) and I save the changes to the layer (so NOT the project save) then QGIS rounds up the ...
1
vote
1answer
1k views

Version problems with Geotools CSV2SHP example

I'm trying to use the CSV2SHP tutorial. I spent some time trying to get it to run but using v10.x of Geotools causes the shapefile to be output with no geometries. For instance if I open it in QGIS, ...
35
votes
5answers
8k views

Advantages of using spatialite over shapefile? [closed]

I found spatialite more useful than shapefiles as it does not have the limitations of shapefile and it is also portable. Many people here use shapefiles to exchange data and even the experts do not ...
14
votes
6answers
2k views

Creating simple image from vector data

Can anyone suggest a quick (and preferably open source) way to create an image from a shapefile. For example, I have a shapefile containing parcel boundaries, I want to create a png file depicting ...
30
votes
3answers
18k views

How to easily edit attribute data using Regular Expressions?

I am writing a tutorial for MSc students that uses QGIS. One of the tasks requires the attribute data to be modified (see pdf draft of tutorial here if interested ). The question is how to get them ...
22
votes
3answers
21k views

Selecting feature types when using ogr2ogr to convert to shapefile?

Shapefiles can only have one geometry type, but many other formats (kml, geojson) can have multiple types. When converting to shapefiles, is it possible to to tell ogr2ogr to create multiple ...
9
votes
4answers
9k views

Convert Polygon Feature Centroid to Points using Python

I would like to convert some polygon based shp files that have several polygon features into points for each feature that would essentially represent the centriod of each polygon feature. I know in ...
18
votes
2answers
26k views

Convert a spatial polygon object to data frame using R

My goal is to modify an existing shapefile by merging certain polygons. After importing the shapefile and using the UnionSpatialPolygons command, I get the polygon outline that I want. However, this ...
13
votes
4answers
675 views

Are long lines in shapefiles to be considered geodesics or straight lines in the 2D latlong space?

Is there a definition on how lines connect vertices in the shapefile format? In the simplest case, imagine a line with only 2 points, from 40,-118 to 40,-112 - that's somewhere random in the US - ...
22
votes
3answers
33k views

How can I get the proj4 string or EPSG code from a shapefile .prj file? [duplicate]

I have to work with a shapefile defined in an unusual projection, which my GIS software does not know about. How can I get the proj4 definition or the EPSG code for the projection?
13
votes
3answers
31k views

Extract Raster from Raster using Polygon shapefile in R

I am new to R and using the raster package. I have a problem extracting polygons from an existing raster file. If I use extract(raster, poly_shape) function on the raster it always creates a list ...
11
votes
3answers
7k views

Divide a complex shapefile into a grid

I have a decently detailed shapefile with polygon/multipolygon features (the file is about 500mb). It's actually a shapefile of the entire world, with the features representing coastlines. I need to ...
18
votes
9answers
8k views

how to overlay shapefile and raster?

I have a shapefile with polygons. And I have a global raster file. I want to overlay the shapefile's polygons onto the raster grid and calculate the mean raster value for each polygon. How can I do ...
17
votes
3answers
14k views

How to create a GeoJSON that works with D3?

I'm simply trying to convert a .shp file to a geoJSON format using: ogr2ogr -f geoJSON output.json input.shp After executing the command nothing seems to be wrong. Here's an excerpt from the output....
16
votes
1answer
31k views

Converting a polygon into a raster using R

I'm trying to convert a shapefile into a raster within R. My approach is to read in the raster as follows: library(rgdal) # Loads SP package by default demo <- readOGR('F:/data/', 'shapefile') # ...
13
votes
5answers
608 views

What in-depth spatial database systems tutorials exist? [closed]

Is there a good tutorial that explains in depth the internals of a GIS and a spatial database system such as PostGIS with examples and without any background assumption? I'm specifically looking for ...
11
votes
3answers
2k views

Which data format typically displays fastest in ArcMap?

My organization is working on an application running on ArcGIS Engine. Previous versions of the application used primarily Shapefiles for displaying roads, parcels, buildings, etc. Since I was ...
11
votes
7answers
10k views

Creating shapefile from current dataframe extents in layout view of ArcMap?

Where is the ArcGIS 10 tool for creating a shapefile from current dataframe extents in layout view? Have looked around and the closet thing i can find is Toolbox's Grid/Strip Map Index tools under ...
6
votes
1answer
6k views

Merging shapefiles with attributes using PyQGIS?

I have some shapefiles. They are all the same kind of shape and all have the same attributes. If I wanted to merge them manually the "Vector/Data management tools/merge shapefiles to one" works fine. ...
18
votes
4answers
72k views

Opening and extracting data from Shapefiles?

We are in need of US highway data. We found it for Florida at the state GIS website. We downloaded the data for Florida highway intersections from here (this is a zip file). How do we use these ...
18
votes
2answers
11k views

Get field names of shapefiles using GDAL

I use GDAL in Python for importing shapefile. I want to know the field names for the file, my current way is: fields = [] for i in range(1, layer.GetFeature(0).GetFieldCount()): field = layer....
14
votes
3answers
2k views

How can I represent distance using the dashes or markers of a vector line?

I am a very basic user and dont know the lingo to get to the gist of my question so some background might help. Ive volunteered to create a pre-incident planning system for my rural fire department. ...
12
votes
4answers
40k views

Reading shapefile using C#? [closed]

I am new to ArcGIS and trying a few things.. I'm trying to read shapefile (which is supplied as an input) using C# and I want to generate a PDF file which contains underlying metadata information (...
12
votes
2answers
16k views

writeOGR with a spatialpolygon simplified by gSimplify

I'm using gSimplify (rgeos package) to simplify the geometries of a shapefile. The funcion works good, but now I can't write the output in a new shapefile. I tried some ways: writeOGR(simplyshape, ...
11
votes
3answers
20k views

Making shapefile from Pandas dataframe?

I´d like to construct a shapefile from a Pandas Data Frame using the lon & lat rows. I have got a csv file and I process it with pandas to make a data frame which is easier to handle Is it ...
9
votes
4answers
20k views

Join CSV file to shapefile

I wanted to join a CSV file to a shapefile. When I identified a field to facilitate the join, e.g., map <- spChFIDs(map, as.character(map$ID)) it returned Error in spChFIDs(SP, x) : lengths ...
26
votes
6answers
40k views

Free tool to convert ArcGIS layer package (*.lpk) to shapefile (*.shp)?

I have received a *.lpk file from Esri's ArcGIS platform that I would like to convert to a shapefile. How can I do this, using only free software?
15
votes
2answers
12k views

How to split non-contiguous feature in QGIS?

I have a shapefile with a feature that is non-contiguous. I want to split the areas on the left from the area on the right. However, QGIS's Split Features tool requires you to draw a line over the ...
13
votes
4answers
5k views

How to reproject spatial data using free libraries?

How can I use free libraries to transform spatial data? For example, I want to change the projection of a Shapefile within the code of my C# web application. How do I do that?
13
votes
1answer
21k views

Reprojecting raster from lat/lon to UTM in R?

i have to turn it into a UTM in order to make the buffer functional. wets<-readOGR(dsn=".",layer="shapefile") r.raster <- raster() extent(r.raster) <- extent(wets) res(r.raster) <- 100 ...
12
votes
2answers
24k views

How to convert a shapefile to WKT?

I'm trying to convert a shapefile into the simple Well Known Text (WKT) format in the example below (from http://en.wikipedia.org/wiki/Well-known_text). MULTIPOLYGON (((40 40, 20 45, 45 30, 40 40)), (...
10
votes
2answers
961 views

What's the batched Refactor Fields tool “field mapping” syntax in QGIS?

In QGIS, there is this nice tool "Refactor Fields" in the Processing Toolbox : Using it on a single layer is fairly straightforward. However, when you plan on using it in a batch mode, one can see ...
10
votes
1answer
2k views

Identify shape of the polygons: elongation, roundness, etc

I am generalizing geological map. In the initial step I am dealing with small polygons which should be either deleted, enlarged, aggregated and etc. Before applying operations mentioned above I ...
10
votes
6answers
9k views

How to add a projection to a Shapefile using open-source tools?

I have been given some shapefiles WITHOUT a projection. So I need to add the projection in order to display it on google map. I found the projection information I need at http://spatialreference.org/...
10
votes
5answers
965 views

Database versus Files for Solo Developer

I'm just getting started in GIS and am interested in using it to create maps of mountain biking trails in my area and nearby. I've been learning QGIS and have made enough progress to generate a decent ...
8
votes
4answers
8k views

Seeking tool to convert GTFS (General Transit Feed Specification) to SHP / KML? [closed]

I need to convert GTFS (General Transit Feed Specification https://developers.google.com/transit/gtfs/reference), data into some GIS data format like ESRI Shapefile or KML or something else. Do you ...
7
votes
1answer
7k views

Is there a QGIS bezier curve tool?

I'm a recent convert to QGIS but have been confused about the lack of support for drawing curved shapefiles, especially when Arc has almost too many. A lot of the work that our consultancy do is based ...
7
votes
3answers
21k views

Creating Polygon Shapefile from list of X,Y coordinates using Python?

I have a list of X,Y coordinates from a csv file, that represent a polygon. I´m trying to create a Polygon-Shapefile from this list. I´ve been trying around and found a possbility to write the list to ...
6
votes
1answer
4k views

Programmatically populating shapefile field with polygon areas in OGR?

I'm trying to programmatically populate a shp field with polygon areas: import sys import ogr ds = ogr.Open( 'tttttttttt.shp', update = 1 ) if ds is None: print "Open failed./n" sys.exit( 1 ...
6
votes
1answer
12k 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?...
4
votes
4answers
9k views

Updating Attributes using Pyshp

Is it possible to update an attribute field in a shapefile using pyshp ? I went through their documentation and all they show is how to create new attribute rather than editing or updating an already ...

1 2 3
4
5
14