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

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531 views

Steps to polygonize raster KML image

I suspect I'm trying to do the same thing as in Convert image in KMZ to polygon. Given a kml displaying an image within a given lat/long boundary, what are the steps I follow to use Quantum GIS to ...
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0answers
176 views

Can I overlay layers in Dealul Piscului 1970 and WGS84 in QGIS?

I have a 10 Gb ECW file (mosaic of a whole county) that is in Oblique Stereographic projection with Datum: Dealul Piscului 1970. The problem was that no matter the Default CRS for new project was, ...
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2answers
892 views

Using raster to clip vector data

I have high res raster data covering 2million km sq, with a field where each cell has a value from 0 to 100. I need to create a "mask" using the cells with a value over 12 in that field. I then need ...
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2answers
2k views

Using OS Mastermap SLDs in QGIS

In an answer to a question asked by @Canningmister, @tjmgis posted an excellent answer Styling OS Vectormap Local in QGIS? about making OS SLD files work in QGIS. As an amateur user who uses QGIS to ...
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1answer
580 views

Vector data(point) is drawn in wrong place on map (OpenLayers)

I need to show a map (world map, used default OpenLayers WMS) and one point on it (with events like onhover, etc). Here is my code: var options = { ...
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4answers
4k views

OpenLayers (allOverlays): Vector layer not rendered without raster layer beneath it

This is another newbie question. I'm trying to create a map using OpenLayers that comprises only of vector layers from a WFS server. However, I'm thwarted because my vector layer won't render unless ...
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1answer
2k views

How to change events in the Oncomplete Drag function in Openlayers

below is code that works for Openlayers drag function: drag = new OpenLayers.Control.DragFeature(polygonLayer, { autoActivate: true, onComplete: function() {alert('Are you sure this is the ...
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1answer
165 views

C/C++/C# Library for raster to vector conversion

I am looking for an "open source" C/C++/C# Library able to convert raster to vector data (Polygonize). I know gdal_polygonize.py is doing the job, but I can't use Python. Portrace is an other option, ...
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167 views

How to plot a shapefile with colors according to a column numbers in R?

reclass = function(x){ ifelse(x == 0, 10, ifelse(x > 0 & x <= 20, 0, NA)) } arch$ranks<-as.factor(unlist(lapply(arch$ranks,reclass)) arch.col = topo.colors(nlevels(arch$ranks)) for(...
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3answers
313 views

ArcMap Change Values Greater than Standard Deviation of Mean to Zero

I have a feature class with greater than 1000 features and I would like to change all values greater than 2 Standard Deviations to a Zero. Seems like I could possibly use Field Calculator for ...
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2answers
1k views

How to Resolve Inconsistent OpenLayers vector position Over Google map [duplicate]

I have an OpenLayers map with a Google base layer and an OpenLayers vector layer on which people can draw their own bounding boxes using the DrawFeature control. I have found that, as you zoom in, ...
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1answer
2k views

provide an alternative “label” when styling vector layer with openlayers

I'm using openlayers 2.12 and I am styling a vector layer using your typical new OpenLayers.Style({ Now, this layer does two things. First , renders polygons from Geoserver, so in the style I have '...
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1answer
802 views

Is it possible to update layer source in qgis

I've loaded a few shape files as layers in qgis, and I'd like to make a duplicate of the project and all associated shape files into a single directory. However, all of the layer sources are still ...
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1answer
888 views

How to highlight track in KML on hover with OpenLayers

I have KML layer with multiple tracks and I would like to highlight them individually on mouse hover. I tried to implement this like in the example found in OpenLayers examples, but couldn't get it ...
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2answers
860 views

Tools/processes that avoid the need for raster to vector converstion? [closed]

A "brute force" method of solving GIS problems that involve acquiring values from raster cells and storing them on spatially overlapping vector features is to first convert the raster to a vector. The ...
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1answer
25 views

Furthest point from polygon/point

I want to calculate distance between smaller dots (they represent towns, villages etc.) and these larger red dots (capital cities of admin. region). My goal is to show wich location is the furthest ...
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2answers
49 views

Group points and compute area

In a point vector layer, how to compute area for 4 defined ranges of values of one attribute? On the example below, I want the total area for each of the 4 colours.
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2answers
56 views

QGIS Convert vector classification map into raster

I tried to convert vector classification into raster file for accuracy analysis following these suggestions My vector data is like this: However, none works The first one, interpolation, resulting ...
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1answer
39 views

Determining of vector dataset single files to specify its size on a disk

I wonder how to get size of disk space that a specific vector dataset occupies on a disk. I didn't find any ogr2ogr util or OGR Python method that can return a list of files that belongs to given ...
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2answers
103 views

Layered world map

First off I just want to say that I am NOT sure if this is the correct place to ask this question; So if it is not, please direct me to the correct exchange. So for the question: I am looking for a ...
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1answer
61 views

Is it possible to remove small transparent outline effects between polygons?

after using the vectorizing tool I get the following result (picture). Around the cells you can see a small "boundary". This thin line is transparent and annoying. Is it possible to remove these small ...
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1answer
122 views

Simultaneous multiple vector layer intersection algorithm

Is there an algorithm, you can suggest or recommend, that I can implement to intersect multiple vector layers? I have a few hundred layers I want to intersect and thinking of developing a little QGIS ...
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2answers
301 views

Exporting layers from ArcGIS into PostGIS while preserving attributes such as color

I have managed to import/convert a KML into ArcGIS 10.0 (ArcMap) using the built-in conversion tools and now have a series of layers. Next, I export these layers to a PostGIS database using the ...
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1answer
227 views

ArcGIS Linear referencing tools duplicating records and erroneous measures

I am using LocateFeaturesAlongRoutes_lr, MakeRouteEventLayer_lr, and MakeRouteEventLayer_lr to combine three different overlays into one based on this question I asked month ago. The code is as follow:...
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1answer
95 views

How do i rescale feature classes of different scales for intersect analysis?

before I intersect 2 feature classes of different scales (e.g. 1:200,000 soil map and 1:25,000 land use map), should I rescale them like how u would resample raster datasets to the same resolution ...
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1answer
292 views

Difference in vector / raster area measurements

I'm comparing raster and vector distance zones. So I created a line, calculated the Euclidean distance, and reclassified the raster to two zones: from 0-10m and 10-20m. To compare it with vector ...
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1answer
92 views

How to put marker on vector layer with lat/lon on QGIS [duplicate]

I have a vector layer, and bunch of lat/lon values. I want to put markers on the vector layer for each lat/lon pair. I have never used QGis, would you help with it. thanks.
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1answer
355 views

Polygonize(raster to vector) [closed]

I have been install QGIS 2.0.1.when I use Polygonize (Raster to vector)for convert jpg to shp I get error message such as: C:\windows\123.exe is not recognized as an internal or external command,...
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1answer
153 views

QGIS problems getting layers to line up correctly.

I am trying to add a raster layer and a vector layer to qgis. I have set both of their CSR to NAD83 Oklahoma North State Plane. It doesn't seem to work even with all the files set to those CSR. ...
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2answers
621 views

MapServer: How to display and style a Text layer?

I'm trying to display a text layer using MapServer, but I'm kind of confused how to get it to display properly. When opening the .TAB file in a GIS application (in this case, MapInfo Profressional) ...
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2answers
272 views

In grass v.drape works with points but not lines

I got an elevation raster map which I interpolate from a point cloud with v.surf.bspline. Then I digitize a couple of points in a new vector layer. With v.drape I'm able to get a height from the ...
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1answer
1k views

OS Vectormap GML files into PostGIS

I am having difficulty in efficiently dealing with OS Vectormap data that comes in GML format. In the past I used the Plugin for QGIS (OS GML Tools) to batch convert folders of compressed GML (.GZ) ...
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2answers
174 views

How to drag a point and then use savestrategy in OpenLayers

Im trying to use the wfs-t in openayers using the savestrategy. I have created a savestrategy and it works when I for example uses the DrawFeature Control to add a point. A new point is added to the ...
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2answers
1k views

How to scale/reduce my polygon without changing the central lat & long?

I am writing a VBA code to resize my polygon, I get a input as vector points(Shape file). The code below resizes it as according to my scale factor but my central latitude and longitude are also ...
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2answers
21 views

Calculate surface area of polygon within the lines of another polygon

I have two shapefiles, both polygons. 1) The first file represents the administrative boundaries of provinces. This file contains a lot of fields. [social, geographic, natural, morphological etc] 2) ...
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1answer
28 views

Self-hosted web app to view raster & vector layers and annotate

I'm trying to find a self-hosted web app that allows you to view a number of raster and vector layers on a draggable web map, and then to 'annotate' the map by adding points to the map with associated ...
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1answer
35 views

Combining overlapping polygons to make a raster

I'm working in Arcmap10.3. I have some polygons layers that over lap that I want to merge to one polygon layer. Then I want to convert it to a raster in the end. I want the top layer of the 4 input ...
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1answer
80 views

Increasing size of buffer based on field in ArcGIS for Desktop?

I am using vector data from a CSV file and ArcGIS. I can use the Geoprocssing tool Buffer just fine, I use these parameters and ArcGIS does produce what I want, however it is way to small (my ...
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1answer
38 views

Polygon to multiline object in ArcMap?

Is there a possibility to create a multiline object from polygon object contours in ArcMap? I found that Edit toolbar allows to create polygons from other shapes, but I couldn't find anywhere an ...
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2answers
181 views

QGIS 2.10, csv points to vector grid

I have a series of point data from a .csv file that I would like to display as a heatmap raster, the .csv data have various attributes with them and I would like to adjust the color ramp based on ...
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2answers
106 views

How to measure the sum of the areas of each class in QGIS?

The project has a layer with several groups of polygons with different weights. Each group is associated to a weight. How can I get the sum of the area of each group?
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1answer
75 views

Land cover modifications in different time periods

I have several shapefiles which contain buildings built in different periods from 1948 to 2013. My question is how could I see which buildings for example in were built 1948 but are missing in later ...
0
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1answer
63 views

joining non-spatial pollution model (csv file) to Qgis

I need help..I have csv file with concentration data but without coordinates. Start of pollution concentration connect with that one point on map. Is there any chance ? Start of pollution ...
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1answer
1k views

Adding in multiple layers in OpenLayers 3

I am trying to add in the following two layers into my OpenLayers 3 map. The issue i'm having is that whichever one is written in last is the only one that is showing. I imagine there is a way to ...
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1answer
107 views

Adding features to a vectorlayer using checkbox

I'm trying to add features to a vector layer using a checkbox. var featureOverlay = new.ol.FeatureOverlay; $("input:checkbox").each(function(){ var $this = $(this); if($this.is(":checked"...
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1answer
83 views

Fill larger polygon empty space with closest subset of polygons

Looking for an ArcGIS or QGIS solution. I need to divide up the space of the large single green polygon. Each new polygon would represent "nearness" to the purple polygons and have the ID of the ...
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1answer
234 views

QGIS 2.8 Convert a vector to a raster layer

When I change a vector layer to raster using raster button->converse->Vector rasterization in QGIS2.8. I get only a black picture. Why is that so and how can I convert a vector layer to a raster ...
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1answer
357 views

How to change the style of a vector layer on a button click

Is there a way to change the style (e.g. color) of a vector layer on button click? I have defined a vector layer like this: new OpenLayers.Layer.Vector("WFS", { style: myStyle, ...
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2answers
228 views

How to read DGN using GDAL in VB.Net?

Reading a DGN file is a big problem for me. I tried more and more but can't find a way to read a dgn(v8) file by VB.Net. After many search, i found out that GDAL can read and write dgn file, but i 'm ...
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1answer
278 views

Apply an sld to a vector layer in OpenLayers

I'm trying to apply an sld style to a vector layer in Openlayers. I already took a look on google and here and I got a lot of informations, but still I don't manage to achieve the result I'm looking ...