Tagged Questions

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.

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4
votes
1answer
2k views

Sea routes network dataset

I am now working on a system to perform routing on a network of shipping lanes. See this dataset that I have as the base: http://geocommons.com/maps/109850 I have postgres and pgrouting up and running ...
7
votes
7answers
2k 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 ...
8
votes
5answers
2k views

How to get an ocean shapefile from a very detailed land area shapefile?

I am looking for a possibility to "invert" a shapefile. What I want to do is to convert a shapefile with the continents and islands into a shapefile that has water polygons. The existing ocean ...
3
votes
1answer
3k views

Free data with good accuracy of Europe and Mediterranean

I'm searching for free data like Europe's coastline and Mediterranean island's names etc. but with good precision. I found some shp file from this site http://www.naturalearthdata.com/downloads/ but ...
5
votes
4answers
3k views

How to change field length in QGIS

I have a shapefile I made in QGIS 1.7.4. One of the fields is a String of length 80. I'd like to make the field accept longer stings, but I can't figure out how to change its length. How do I do this? ...
6
votes
1answer
3k views

GIS, R and shapefiles

I have some data that encodes locations in certain countries, such as the US and China, that I would like to map. The data includes location name in Latin, extended Latin and other scripts (Japanese, ...
3
votes
2answers
2k views

Using PHP to create a GIS Web application

I've developed many GIS Applications using ESRI ArcGIS 9.3 and 10.0 for ASP.NET . I'm wondering if i can do a GIS application using my SHAPE files and Pure PHP scripting . I've googled for that ...
9
votes
2answers
8k views

Merge polygon in a shapefile based on a field value

Hello I have a shapefile with a lot of polygons in it. These polygons are grouped into a category: district. How can I merge the polygons based on the same name of the category within this shapefile?
4
votes
1answer
376 views

How to customize QGIS for vehicle tracking?

I'm doing a project on vehicle tracking using GIS - for that I'm using the open source software package QuantumGIS (QGIS). I would like to know how to customise QGIS using the python console to edit ...
2
votes
1answer
2k views

merging 2 polygon adjacent to each other using R

I have several shp files which are the components (or tiles) of a map, I have joint all these tiles together to have a large shp file. Then I realized some of the polygon is now splitted into 2 ...
3
votes
2answers
1k views

How to insert geometries from shapefile into existing table?

I'm running into a problem trying to figure out how I should insert a GIS coverage polygon into an existing table. I'm primarily using QGIS and the PostGIS Manager plugin to handle it. After some ...
4
votes
1answer
1k views

Union, Dissolve, Buffer — multiple layers, all in one step?

I'm a new user of Quantum GIS (1.7.3) and I need to repeat a task multiple times, so I'm wondering if there is a quicker way to do the following (with three or more polygon layers - each layer has a ...
5
votes
1answer
437 views

Ogr2Ogr exported this boundary 90 degrees incorrectly

I've got some GEOGRAPHY data in my Sql Server 2008. I wish to export it as a shapefile (so I can import it into QGIS) and when I do, it's rotated 90 degrees to the left and then flipped 180 degrees to ...
0
votes
1answer
217 views

identifying single overlaping features from a GeoServer layer

I'm trying to use GeoServer to display features from a PostGis table the url will look similar to this. Example URL ...
2
votes
2answers
186 views

Color a layer of the map based on the location of dots on another layer

Thanks for helping me in GIS 101 Problem #2, now I have followup questions: I created a map as below: The map is created using the following script: ct <- ...
4
votes
1answer
3k views

How to plot points on maps using ggplot2 and R?

Thanks for help me in GIS 101 Problem #1, now I have geocoded a few hospital in Connecticut using google map, I have able to visualize them in QGIS, now I am trying to do it in R. ct <- ...
2
votes
0answers
461 views

How to overlay geographic data from multiple sources?

Being a newbie to GIS, I am trying to create a map using shapefiles and addresses found online, as an exercise. The steps are below: I downloaded a shapefile of Connecticut from the following link ...
4
votes
2answers
1k views

Using QGIS, how can I add a bounding box attribute?

I have a shapefile where I am exporting the features to GeoJSON objects with ogr2ogr based on a simple where clause. One thing that I would like to be included in the GeoJSON object is the 'bbox' ...
1
vote
0answers
345 views

RadMap for Silverlight reading in Shapefiles

I have created shapefiles now which is basically a couple of polygons representing rooms in a building. They appear fine in QGIS, but when I try and load it into the application (RadMap in ...
3
votes
1answer
4k views

Converting kml to shape file via ogr2ogr including all attributes

Here is the example kml file I am using: <kml xmlns="http://www.opengis.net/kml/2.2"> <Document> <name>My Golf Course Example</name> <Placemark> <name>Club ...
5
votes
2answers
2k views

ogr2ogr kml to shp conversion created 184 shapefiles?! What am I missing?

I'm trying to convert this KML dataset of ice arenas to a shapefile using ogr2ogr (GDAL 1.8). After some initial troubleshooting to get the script running, it's creating 184 different shapefiles (736 ...
5
votes
1answer
409 views

How to divide a polyline by intersecting isochrones

I have two shapefiles, the first representing a path (a polyline with a single category), the second representing isochrons from the same origin (point 0) which intersect the above mentioned path. I ...
3
votes
2answers
5k views

select column in csv file in Python

I would like to study a range of data using the same technique in ArcMAP (it will take too much time to do it one by one ;) !). I've been just recently playing with ArcMAP and Python (which can help ...
49
votes
6answers
1k views

Are there any attempts to replace the shapefile?

Recently I've been spending a lot of time converting perfectly good field names like "Percent of citizens age 25 and over with a bachelor's degree or higher" into things like "edbchogtr" to meet the ...
1
vote
1answer
3k views

Where to find World Latitude and Longitude Grid (arctic circle, equator, tropics..) in shapefile/ e00?

i was wondering if you could teach me how to find World Latitude and Longitude Grid (arctic circle, equator, tropics..) in shapefile/ e00? I saw some of these datas affiliated with universities but ...
0
votes
1answer
960 views

How can i add sharpmap to visual studio2008?

i have just installed visual studio 2008. and i want to add sharpmap or any other tool so that i can add shape file in .net. I have selected sharpmap because by the search i have got that sharpmap is ...
1
vote
4answers
299 views

How to work with NREL data in QGIS?

I would like to use QGIS to display solar data from NREL. The file is supposed to provide solar radiation data of Colorado. However, I have some trouble to select this data in QGIS: In QGIS, I select ...
12
votes
2answers
3k views

API documentation for Gdal/Ogr with C#

I want to assign projection to shapefile in my web C# application, for this i am using Gdal/OGR/OSR C# bindings and add osr_csharp.dll and ogr_csharp.dll references. But i am facing some difficulty ...
3
votes
1answer
1k views

C# Library for converting Shapefile Projection

Is there any C# library which can take a shapefile as an input with projection information defined (e.g, EPSG 3011) and return a new shapefile with user specified projection (e.g, EPSG 4326) ?
1
vote
2answers
496 views

NA values in dbf when exporting shapefile from R with writeOGR?

I´m writing an esri shapefile from R (2.14.1) on windows, using writeOGR in the rgdal package, in the resulting dbf file, NA values in the spatialpointdataframe (in numeric columns) are not translated ...
2
votes
1answer
929 views

What is the most efficient way to create a shapefile from resultset using geotools

I am facing a problem to write to shapefile (geotools) with respect to time, memory etc. My workflow is something like reading spacial data from database Oracle with attributes and coordinates (can ...
4
votes
5answers
2k 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 ...
2
votes
1answer
606 views

How to write to shape file in MapGuide

Here the code I have written to a Shape file in MapGuide Open Source (in PHP running on IIS 7.5). The code is actually the modified class MarkupEditor (markupeditor.php) from the General Tracks (Gt) ...
7
votes
3answers
4k views

How to delete multiple selected polygons at once?

I'm new at this, a novice at best. I'm using QGIS 1.7.3. I simply want to select a large number of polygons on screen and hit the delete key to delete them and resave the shapefile. Can this be done?
10
votes
3answers
14k views

How to convert .shp to .csv including attributes AND geometry?

I have a .shp file 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 ...
3
votes
3answers
5k views

How to extract latitude/longitude values for specific points from a shapefile?

I have obtained public crash data for the state of Minnesota. I would like to be able to programmatically extract the latitude/longitude of each crash using this data in combination with a series of ...
15
votes
4answers
13k views

How to open a Shapefile in R?

I need to open a shape file from ArcMap in R to use it for further geostatical analysis. I've converted it into ASCII text file, but in R it is recognized as data.frame. Coordinates function doesn't ...
5
votes
3answers
6k views

How to convert coverage (.adf) to shapefile?

Is there any tool or software except ArcGIS which I can use for converting coverage (.adf) files to shapefiles?
1
vote
0answers
472 views

How to fix QGIS Server internal server error when using shapefiles?

i read all the questions with 500 server error i could find on the net but nothing seems to solve my problem: I installed qgis and all depending packages on a debian server. The first ...
23
votes
6answers
1k views

“Oddities” in the Shapefile technical specification

I've been writing a shapefile parsing library, and have encountered a couple of design decisions in the specification that I don't immediately understand. I'm hoping there's a wizened old ESRI ...
1
vote
1answer
2k views

How to generate shape file from Excel or CSV files? [duplicate]

Possible Duplicate: How can I convert an excel file with x, y columns to a shapefile? Probably this could be an easy question for most of the people. But I would like to know the way to ...
2
votes
1answer
821 views

Shapefiles on WMS Server

I've been reading about using WMS servers to server shapefiles. When a server does support shapefiles over WMS, what format does the client download the shapes in? Will it typically be an image format ...
3
votes
1answer
492 views

Extract data from QueryLayer to Shapefile

I have a QueryLayer that I need to export as a shape file. This was previously implemented as an ArcSDE feature class which we converted to a QueryLayer (running against SQLServer) in order to have ...
6
votes
1answer
2k views

Spatial distance join between polygon and points using R?

I'm figuring out how to do a Intersection (Spatial Join) between point and polygons from shapefiles. My idea is to get the closest points and those points that match completely inside the polygons. In ...
8
votes
4answers
1k views

Is there a mapping between OGR and python data types?

I'm writing a shapefile using OGR in python, creating fields on-the-fly from a python data source. Creation of a new field requires an OGR data type, is there a mapping between OGR and python data ...
2
votes
1answer
438 views

ArcMap v10 - Polygon Layer - Keeping one polygon above another

I have a shapefile with polygons of differing colors. I am using a white hash pattern to represent partial ownership. In short - Polygon #1 is Green and Polygon #2 is a White Hash pattern. ...
9
votes
5answers
1k views

Looking for USDA plant hardiness zone shape file

given that this is a USDA resource I really thought that it would be available online somewhere, but for the life of me I cannot find a shape file for the USDA plant hardiness zones anywhere. anyone ...
10
votes
5answers
570 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 ...
4
votes
2answers
871 views

How to cut a shape file?

I want to use a shape file of the Corine Land Cover. This covers all of Europe, but I am only interested in the area of Scandinavia. How can I cut this file using free software (preferably a ...
11
votes
1answer
3k views

Instantiating spatial polygon without using a shape file 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 ...