A coordinate-based data model that represents geographic features as points, lines, and polygons.

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4
votes
1answer
252 views

Automatically updating user-edited features in QGIS plugin

I am working on a plugin for QGIS (2.12). It uses data stored in an Spatialite database. When the user creates a new feature, the plugin should: update the feature attribute table (the popup form ...
42
votes
6answers
95k views

What are Raster and Vector data in GIS and when to use?

What are raster and vector data in the GIS context? In general terms what applications, processes, or analysis are each suited for? (And not suited for!) In answering someone's question today, I ...
1
vote
0answers
46 views

save shape file as grouped/layered vector file

I want to get the 10m natural earth countries file into a mercator projection and then into a vector file (svg, ai, etc) where for each country, its main land and any of its islands are in a single ...
2
votes
2answers
72 views

R use data in SpatialGrid to create SpatialPoints

I am trying to make a grid of points to overlay on a raster of vegetation of Kansas, U.S.A. My idea is to use the points as a sort of centroid for the raster pixels, which are 30m resolution. When I ...
3
votes
1answer
49 views

Land use change detection with large amount of vector files

Im doing a project where I'm creating a map that shows how land use changed from 1990-2000 for the city of Minneapolis. I have three files, one of the cities boundaries, one with the land use of the ...
1
vote
0answers
115 views

Method for identifying upstream segments

I need to add to the attribute table of a stream network layer a column that can identify all upstream segments that contribute to the segment (for each segment). My best idea at the moment is to ...
2
votes
1answer
59 views

Converting an ENVI raster as point shapefile for editing in ArcGIS?

I have an ENVI raster with multiple classes inside. I tried to export this to a vector so that I can convert it to a shapefile in ArcGis (I want to manually edit/delete points in the raster), but the ...
2
votes
1answer
376 views

ArcGIS, How do I get smoother contours?

I am trying to get nice smooth contours using ArcGIS. I have already smoothed out the DEM using focal statistics, simplified and smoothed the contours. The current result looks like this, which is way ...
1
vote
2answers
139 views

How to combine two polyline shapefile together

Here is my question Two shapefile: * A: represent the outer boundary of the city area * B: represent the inner boundaries of the city divisions. I want to * Combine these two shapefile * ...
16
votes
4answers
44k views

Extract Raster Value into Polygon Attribute

I have Raster Data for a State which has Elevation Data in its pixels. I also have Vector layer which has the 300 divisions of State. what I need is, I want to get the average elevation value of ...
2
votes
0answers
33 views

Converting u and v from WGS84 to NZTM2000 - Do I need to do vector conversion?

I have u and v wind component values in latitude and longitude in WGS84. I want to convert this to NZTM2000. I've converted the lat/lon in ArcView - (and will try in R) - but do I need to also do some ...
3
votes
2answers
59 views

How to make a line shapefile converted from a gpx track file display over basemaps such as OpenStreetMap?

I have created a line shapefile from a Garmin gpx track file using QGIS 1.12.3 Lyon. Resultant vector file displays properly with other vector shapefiles. Problem is that created vector file (line ...
2
votes
2answers
648 views

Loading Vector Layer using python console in qgis

I am using qgis2.6 version and new to pyQGIS. I tried to load a vector file using python console in qgis. I don't know where I am wrong. The layer was not loaded and does not show any error too. Help ...
1
vote
1answer
120 views

Import vector PDF into MapInfo

Is it possible to import a PDF with vector layers into MapInfo as vector layers? If yes, how would I go about doing this?
16
votes
4answers
33k views

How to convert a vector layer to raster?

In qgis in the raster menu there is an item "convert vector to raster". This behaves strangely - I do not understand how it is supposed to work. I can select a vector file, an attribute and an ...
4
votes
1answer
119 views

QGIS Composer Distorted SVG PDF Output

I've noticed that some SVGs are distorted when outputting to a vector PDF from QGIS. A good example is NorthArrow_07.svg. The image on the left is how it looks in the composer and the image on the ...
0
votes
0answers
14 views

How to decide a which server is best for geo-spatial data servicing? [duplicate]

I want to serve both vector and raster data sets of large volume (ex: for a country). Right now I'm using GeoServer for vector and MapServer for raster. Is there any literature or reference such ...
0
votes
0answers
36 views

Incomplete/incorrect extraction of raster values from shapefile in R

I am having trouble correctly extracting raster data from all the polygons from a given shapefile in R. The raster and shapefile have identical CRS in QGIS (EPSG:32654, WGS84 / UTM zone 54N). After ...
2
votes
0answers
22 views

QGIS upgrade from 1.8 to 2.12: Vector layers are not displayed

I just updated my very outdated version of QGIS. I was running 1.8 and thought the new version would work out a couple kinks that had developed. Well, now I can't even figure out how to make my vector ...
2
votes
1answer
23 views

Multi-string data-set without z layer, applying ordinal values as a workaround

I'm new to GIS and have been learning a lot over the last few weeks, however, I've finally come to a point where I could use some help. I'm working with the pdx_streets data-set from http://www....
1
vote
0answers
32 views

How to get a multi-attributes vector from an SRTM raster in QGIS?

I split an SRTM raster into 3 different raster files representing the altitude, the slope and the exposure, using QGIS DEM analysis tools. How can I output a single vector file with the 3 attributes ...
3
votes
1answer
254 views

Is there a decent algorithm in QGIS Process Modeller to create a grid?

I am using Process Modeller to automate merging several vector layers and then creating a grid to cover the extent of the merged layer. There are functions which already exist which are not listed in ...
0
votes
1answer
277 views

Openlayers stylemap label not working wfs

I have created a style map like following: var scadaPointStyle = new OpenLayers.StyleMap({ "default": new OpenLayers.Style("null", { "rules": [ new OpenLayers....
2
votes
1answer
105 views

QGIS - PYQGIS Import gpx as vector layer

I'm trying to use the python console to import some gpx files as vector layers. When I do it manually I have to choose which layers to add, my options are: I've tried various versions of the code ...
2
votes
2answers
162 views

How to label one point bigger than all others in a layer?

I have a point dataset in one layer. I labelled all points but I would like to label one point larger size than other point labels. How can I do it? Merzifon and Bahçecik are in the same point ...
3
votes
0answers
29 views

zonal statistics / join with two vector layers [duplicate]

I have a shapefile containing three polygons of river basins with different values. I want to know the average values per country. The country thus contains three river basins. When I use join in ...
5
votes
1answer
87 views

Aggregating polygons with space between them

Im currently editing a large dataset that has large chunks removed throughout (buffered road network). The areas adjacent from each side have coinciding attributes, but have this large erased area in ...
7
votes
3answers
1k views

How to define layer's CRS and avoid the CRS dialog in PyQGIS?

There is an existing Shapefile, which I want to add. At the moment my code looks like: self.iface.addVectorLayer(self.shpFilePath, "Track", "ogr") It works fine, but i want to define the crs ...
6
votes
3answers
1k views

WFS to Vector Tiles

Is there, by some miracle, an existing piece of software which is able to convert a (3rd party, GeoServer) WFS feed into vector tiles? In a utopian world, this would happen on the fly, but a download/...
4
votes
3answers
884 views

3d vector and geometry operations in open-source GIS

There is some really good open-source software available to work with 2D vectors. For example QGIS has operations like buffer / clip / dissolve / select by location / join attributes by location... ...
2
votes
1answer
55 views

Adding new columns from other shapefiles - Land use density

New here but I've been following the stack exchange for a while to get many answers on my newbie journey in GIS. I'm trying to find out how to merge different point in polygon classes by column. ...
2
votes
0answers
78 views

QGIS 2.12.3 Crashes on buffering line vectors

I'm using QGIS 2.12.3 and I'm trying to create a buffer of 100 mt around a line vector using the Vector - Geoprocessing Buffer tool, but qgis crashes at every try. I've already checked that the RS of ...
2
votes
2answers
89 views

Split Vector Points/Polygons by Vector Grid and assign to relevant grid

I have 3 vector shapefiles (1: Point, 2: polygon, 3: vector grid) that I would like to combine so that the points and polygons are 'assigned' to the relevant grid cell within which they are contained, ...
1
vote
1answer
110 views

Can multiple point symbols be stored in one QGIS layer?

I'm new to QGIS, indeed fairly new to GIS systems in general. I have been asked to create about 20 small maps for a local historical society. The maps are for walkers to follow various routes passing ...
1
vote
1answer
291 views

Vector layer visibility using min/maxResolution is not working in Openlayers 2

I am using OpenLayers 2 and Geoserver. I have a few WFS layers and an OpenStreetMap as a Baselayer. I want to change the vector layers' visibility at certain zoom levels, by using min/maxScale or min/...
3
votes
2answers
554 views

Assigning RouteIDs to polyline feature class in ArcGIS Linear referencing?

I have a Linear Referencing Route System in ArcGIS Geodatabase format (polylines with M values) and a separate polyline feature class of short segments (called TMC) that do not have RouteIds currently....
3
votes
1answer
39 views

How to combine 2 vector shapes created from raster files

In Qgis 2.12 Lyon, using windows 10 I downloaded 2 raster files from an area of my interest. The rasters were on information about precipitation and evapotranspiration. Each cell had a value. I ...
1
vote
2answers
59 views

check the “quality” for (poly-)lines (density of vertices)

I want to check the quality of digitized tracks. I suppose, that a track with a lot of regular vertices has got a good quality. And a track with less regular vertices has got a poor quality. Maybe, ...
1
vote
0answers
45 views

QGIS polygonize tool not working [closed]

I am having a problem using QGIS ver 2.10.1 Pisa. I am trying to use the polygonize function on a raster .tif image, and it runs, but only produces a thin sliver of polygons at the top, then stops ...
0
votes
0answers
17 views

Arrangement of vectors and matrix in text file?

My ASCII file has a vector of latitudes, and the indices of those latitude values tie latitude values to the data sharing the same index. That is, if given: latitude[x=0,1,2,3] = 10, 20, 30, 40 ...
0
votes
0answers
29 views

How to combine population density data to land use data?

i have census data and land use data in vector format. I tried to combine the population density vector data with land use data set, but every-time it gives me wrong output. Moreover, my land use ...
2
votes
1answer
95 views

PyQGIS: Change attribute value doesn't work, results in NULL

I am writing a QGIS plugin, which at one point attempts to change several attribute values on a layer. However, in the end no changes are made. If I punch similar code into the built-in Python Console,...
1
vote
0answers
19 views

How do I generate a sampling path by numbering points?

I need to number points from left to right and then the next row of points the numbering must continue from right to left, then again from left to right the row thereafter - and so on, and so on. ...
2
votes
0answers
54 views

Combining adjacent shapefiles and merging neighbor polygons currently divided by quad boundaries

The project I'm working on has been mapping ecological sites in ArcGIS on a quad-by-quad basis for the past 10 years. When entered into GIS, each quad has its own shapefile and the sites are cut off ...
3
votes
4answers
3k views

Scriptable way to merge polylines that join in ArcGIS

I have a number of polylines (around 9000), a number of which have one or both ends touching another polyline. I would like to merge these ones together into one polyline - thus reducing the number of ...
3
votes
2answers
233 views

QGIS Real-Time Vector Layer Creation

QGIS is running on my Windows PC. I have a CSV file on my PC that is remotely updated with values of a raspberry pi's GPS position and some wifi-status readings. Is it possible to create a vector ...
2
votes
1answer
53 views

Error when trying to subset a vector to a dataframe

I'm not sure if I've used the correct terminology in my title, so please forgive me if that doesn't entirely make sense. For the sake of reproducing my example, I've created a dummy example. As usual,...
6
votes
3answers
103 views

Select all polygons that are completely within a circular buffer

I made several buffers around some points. Now I want to select all polygons that are completely within this buffer. My problem is that I also get the polygons that are partially outside of the buffer....
4
votes
0answers
71 views

Buffer neighbouring polygons without overlap using QGIS

Is it possible to create a buffer around neighbouring polygons, so that the new polygons do not overlap? Preferably in QGIS but any other tool will do. So instead of the first result I would like ...
1
vote
2answers
83 views

Vector to raster conversion [solved]

I'm using GRASS but, in case, I'm also familiar with R and QGIS. I'm trying to convert a vector area map into a raster one. My problem is that the resolution of the raster is too low (and I can't ...