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

learn more… | top users | synonyms (1)

1
vote
2answers
1k views

OpenLayers vector does not draw (or re-draw) on zoom level change or layerswitcher off/on

Here is the full code (i'll highlight the important parts after): jQuery(document).ready(function($) { // ...
2
votes
4answers
310 views

How to convert a vector map to raster in Qgis?

I am creating a thematic map (vector data) with different classes. How to convert this vector map to a raster map, keeping the classification?
0
votes
1answer
17 views

Retrieve MapBox tiles in vector format rather than raster

I am using MapBox and I would like to render my tiles directly from vector format but I was not able to find how to retrieve the tiles in vector format rather than bitmap. So, when I use this url: ...
2
votes
1answer
1k views

How to deactivate Vector Selection In OpenLayers wms features

This is my sample code and work fine :), But I have a little problem, I'm using multiple layers (WMS), when I zoom the layer will be shown or hidden. In my example bellow when OpenLayers level zoom ...
1
vote
1answer
191 views

QGIS field calculator expression: selecting min/max values within field groups

I am new to using QGIS (previously used Arc) and trying to get my head round the expressions and Python. I have series of polylines representing routes and require the linear distance from the ...
0
votes
0answers
14 views

Is QGIS Server working like this?

On CentOS 7 I have QGIS Server and QGIS Desktop installed. In QGIS Desktop I created a project with raster and vector data and saved it in a ".qgs" file. Then I copied the file in ...
0
votes
1answer
237 views

Geomedia WebMap WFS to vector marker layer in Openlayers

Looking for minimal example/advice on getting a WFS service to show up as a vector layer with markers/icons in Openlayers map. I have created the WFS service in Geomedia WebMap 6.01.11.19 and the ...
2
votes
1answer
373 views

OpenLayers - cannot set layer opacity

I have the following problem: by default, you can simply change the opacity of layer by writing for example: layer.setOpacity(0.3); But when I add it to my map SelectFeature controls, my layer is ...
2
votes
1answer
44 views

Extracting area from DEM Raster?

After applying constraints to the DEM I polygonised the raster (using GRASS r.to.vect.area) The result is shown below with a lot of vector with resolution = [30 * 30] Is there any solution to make ...
0
votes
0answers
7 views

Sky View Factor of building roofs => Vector algorithm [duplicate]

I'm currently working on a project in which I'm trying to assess the SkyViewFactor of a given roof using building vector data. I've already managed to build a process based on vector rasterization ...
0
votes
1answer
42 views

QGIS Vector Data with blank attribute tables

I have vector data shapefiles for Manitoba, but there is no names in the attribute tables. It seems Manitoba is still working on their attribute data. Is there a shapefile I can download to get these ...
13
votes
3answers
5k views

How to find and merge duplicate points?

I have two point shapefiles: Red and Blue. Each point shapefile has a z value which represents a radius (i.e. represented as buffers in the example). A duplicate point is defined as a point that ...
0
votes
1answer
17 views

Intersection of two vector tables data in postgresql

I have satellite raster data is converted in to pixels using create table gtru_tile_pix as SELECT (ST_PixelAsPolygons(rast)).val, (ST_PixelAsPolygons(rast)).geom FROM ...
2
votes
0answers
58 views

How to tell if map service is fully vector or raster?

sorry if this is a duplicate, but I was wondering how to tell if a map service (in web browser) is vector based or raster based? What I think to understood so far is that Google Maps for example is ...
4
votes
1answer
92 views

Creating shapefiles using textfiles in QGIS

I have a shapefile in QGIS which has polygons in it . There are several other attributes for each feature . I want to add another attribute to each feature . The value for this attribute is available ...
0
votes
2answers
38 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 ...
0
votes
0answers
26 views

Aggregate/merge data upon insert into PostGIS (via gdal)

I am working on a project where I take a large raster file (1.5GB+), put it through a number of image-processing operations, and finally convert it to vector data. Being that the raster is large, I am ...
3
votes
1answer
95 views

Shifting an entire .las file in Z?

I have a set of .las tiles. I needed to edit one of the tiles in Trimble's Inpho DTMaster to remove some noise. The coordinates are correct in the program, showing a my desired elevation. On export, ...
4
votes
1answer
314 views

Sketch event in Openlayers 3 drawing interaction

For drawing Polygon in OpenLayers 2 we could use as follow: function drawEnd(){ ... } function putPoint(){ ... } function sketchModified(){ ... } function cancel(){ ... } var ...
0
votes
0answers
13 views

Problem with VectorLayer created in memory

I am working in c++/QT whithnthe qgis API c++ I had to build a personnalized vectorlayout called "TRACKS" , so i write a function that create in memory the vectorlayer like this : QgsVectorLayer ...
0
votes
0answers
6 views

How to make coincident a vector layer and a bitmap constructed from Google map tiles using programming

I can make a bitmap file from tiles that I receive from Google map using X_Tile,Y_Tile and Google map zoom parameters successfully.First I use a vector layer to find map extent in UTM,so I have ...
1
vote
2answers
14 views

Building error with QgsVectorFileWriter

I am working with qgis api c++ 2.8.2, in c++/QT 4.5 I try to save my List of QgsField but I have the error message : no matching for call to 'QgsVectorFileWriter' I took the sample from here : ...
0
votes
1answer
198 views

Openlayers 3 Circle Vectors Not Visible

I have two coordinates which are projected in EPSG: 3857 coord1 = [-10399758.486973494, 5604341.818491254] coord2 = [-10402629.416641055, 5593700.936383396] I'm trying to get them to appear, ...
1
vote
3answers
53 views

Generate line from unordered set of points

What is the best method to take a set of points and generate a line? There are too many to simply guess a "connect-the-dots" situation & These points do not have an attributes in which they can ...
1
vote
1answer
18 views

Mapping continuous vector data on a continuous colour gradient in ArcMAP 10

I'm plotting vector data for different attributes for countries across Europe. I've used symbology to plot categories of countries. However, the data are numbers so are on a continuous scale. I would ...
6
votes
3answers
2k views

Easily calculate “roundness/compactness” of a polygon

I am trying to find ways to quantitatively describe the shapes of various polygons. For my project, these polygons represent lakes, rivers, lagoons, and parks. So they can be almost any shape. One ...
1
vote
1answer
211 views

Overlapping polygons in the same layer

I am working in QGIS on a vector layer where areas are classified using an attribute "typo". The problem I'm encountering is that many polygons are duplicated or overlapping, with the result that some ...
0
votes
1answer
47 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 ...
1
vote
1answer
42 views

Identify nodes in GRASS

Apologies if this is a really basic question but I have been unable to sort this out: How do I identify nodes in GRASS? Specifically, I am running a Salesman analysis and get the following error ...
1
vote
1answer
18 views

How to force GeoServer to remove, or change, NoData Value from GeoTiff?

I am trying to display vector data of state borders, downloaded from GeoServer as GeoTiff, in QGIS. By default downloaded raster looks like this: After disabling NoData value in ...
1
vote
0answers
61 views

How to create contours from an IDW raster

I'm new to QGIS and am trying to create vector contours from this IDW raster. I followed Ujaval Gandhi's "Interpolating Point Data" tutorial step by step but am not getting the same results for step ...
0
votes
0answers
25 views

Making raster from vector

Have you ever met with nan value in raster? Im making raster in qgis from vector (one point) and all I have got is nan value and black raster.
2
votes
1answer
34 views

How to create a new empty memory layer with fields scheme from other layer in QGIS?

Being a complete noob with python so far, I got inspired by this answer: http://gis.stackexchange.com/a/155988/8202 to dive into it a bit. When creating features in a new target layer from an ...
0
votes
1answer
160 views

get and change style property openlayers

i need to change the property of some style after its created, and i need to change it with knowing only the string of the property name. i am getting string like "fillColor" and value like "blue", ...
0
votes
0answers
18 views

Vector layers don't seem to be exhibited properly [duplicate]

I'm a veterinarian that uses qGIS for making basic outbreaks maps, and am trying to branch out and expand what I'm doing. When I first started using qGIS 3 years (I believe it was 1.7), ago, when I ...
0
votes
1answer
1k views

Draw order (zIndex) of OpenLayers polygons and points in the same layer

My question is similar but slightly different from this one: http://stackoverflow.com/questions/5003349/openlayers-vector-features-z-indexing I have an OpenLayers Vector layer which contains polygons ...
1
vote
1answer
79 views

How to get smooth contours from points or IDW raster in QGIS

Hello I'm an artist trying different ways of drawing contours in QGIS using points with income values. I've been able to import a shp file with the data, create a layer with centroids of the census ...
2
votes
0answers
27 views

Creating a 3D model of airspace that I can interrogate to see if some other feature (like a tree) will intrude into the airspace

The goal is to create a 3D model of imaginary planes in space that I can interrogate to see where other objects in the vicinity of the model cut through any part of that plane. For example, an ...
4
votes
3answers
200 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
94 views

How to plot certain values of a column in R?

Lets say we have a shapefile of cities with a column called category cities@data category A B A C A A B C How can i plot the A category only etc? Tried c<-cities$category[A] ...
0
votes
0answers
33 views

How to run Mapbox Vector Tile Mini Server?

I am trying to make an offline map for the vector tiles that I've exported from Mapbox Studio (mbtiles). I found this : https://github.com/BergWerkGIS/mini-server I have it downloaded on my ...
0
votes
2answers
35 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?
4
votes
1answer
4k views

Change vector projection in Openlayers

I have added vector layer to map: vactorTest = new OpenLayers.Layer.Vector("Editable Features", { strategies: [new OpenLayers.Strategy.BBOX(), saveStrategy], projection: new ...
3
votes
1answer
33 views

QGIS Convert bathymetry shapefile from fillable to strokeable

In Java I would like to stroke the bathymetry depth lines instead of filling the area. I'm starting with the Natural Earth Bathymetric Data: ...
1
vote
2answers
75 views

Add overlapping polygons

I have a feature class that contain many overlapping polygons. Each polygon has a field value which I would like to add together wherever the polygons overlap. There are about 100 polygons each with ...
12
votes
6answers
5k views

Converting GeoPDF to vector format like CAD or shapefile?

I want to convert a GeoPDF that has vectors entity in it to a vector format and preserve the real coordinates of these vectors. The GeoPDF has been exported from ArcMap and has layers in it. I have ...
1
vote
0answers
29 views

How to convert GeoPDF to ArcGIS with annotations (arcmap original labels)?

I've got a GeoPDF file that contains vector and annotation data (arcmap labels). I need to convert it into a feature class. I've tried to follow the former questions that been asked here: Adding ...
2
votes
1answer
33 views

Multiple display of vector layer in a qgis plugin interface

def initGui(self): """Create the menu entries and toolbar icons inside the QGIS GUI.""" icon_path = ':/plugins/cropEt/icon.png' self.add_action( icon_path, ...
1
vote
1answer
30 views

Clip & save layer using OpenLayers 2

I ma currently developing a web mapping app. How do I make it possible for my app to clip and save area of interests or area I am working on. I can create a vector layer, modify it and delete if I ...
1
vote
0answers
42 views

Turning “normal” Vector Data into a GIS

I have a map in Adobe Illustrator with several vector layers. ( Therefore the vector data have no spatial reference and no attributes. What is the best way to turn these vector data into a GIS and ...