A layer is a collection of information. It contains specific elements of a gis in a specific presentation method (e.g raster or vector layer). Layers can be edited separately in order to create individual toppics for a map.

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725 views

Creating a layer after using SelectLayerByAttribute_management

Is it possible to use an existent layer to do a selection by attributes without having to use MakeFeatureLayer_management first? Because I already have a layer with the same name as the feature class ...
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1answer
199 views

How to make a virtual layer from ogr geometry?

I know how to do this: nodes = driver.Open(node_nav,0) node_lyr = nodes.GetLayer() node_lyr.SetSpatialFilter(None) But how do can use the layer methods on a geometry I created from scratch? ...
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1answer
107 views

Differences between Arc 10.0 and Arc 10.1 Layer files

We have a program that cannot import Layerfiles from 10.1, but instead changes them to 10.0 layer files. I'm wondering if there is any Layer functionality that is lost in this transition. Right now ...
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77 views

Making a KML layer “always on”

Is there a KML tag or specification by which you can force a given layer (specifically, a screen overlay) to be "always on", in that there is no way for the user viewing the file to make that layer ...
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1answer
298 views

Openlayers: How to make layer come to top after choosing it in layer switcher?

I have a base layer and 3 image layers . I also have setup a layerswitcher so that user can choose which layer is to be overlayed on the base map and I have 3 sliders such that user can choose the ...
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1answer
447 views

Why does arcpy.mapping.Layer give Runtime error: CreateObject Layer invalid data source?

I want to connect an existing .lyr file to a variable defined as lyr2. lyr2 = arcpy.mapping.Layer(r"C:/Iso100Red.lyr") Although its a .lyr file I´ll get this Errorcode: Runtime error : Object: ...
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1answer
187 views

QGIS Layers Not Lining Up

I am new to QGIS, I have been using ArcGIS for most of my maps. I have two layers that are not overlapping properly. One is a shp file from a GIS clearinghouse and another from a delimited text ...
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1answer
308 views

how to make transparent layers with Google earth layer?

with your help, i solved most of my problems, but here is another one - i guess, a smaller issue... I managed to get Google earth layer, but when I add my GPS gpx files, are all hidden under the ...
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2answers
3k views

How To Highlight Roads?

I wish to change the colors of various roads on a map and save the changes to either a "personal map" or a "map layer." The personal map could look something like this, except it would need to have ...
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1answer
64 views

Popups on Layer (OpenLayers)

I have the following situation: i display points and point informations in popups. the points are added to a layer. The popups are added to the map, with map.addPopup function. It works great. The ...
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0answers
114 views

QGIS layers not adding properly

using QGIS 1.8.0 lisboa on windows 7 pc adding vector layers and they are not adding properly they don't show up in the layers list but they are there when I happen to merge the the layers ...
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5answers
3k views

Is there any way to extract coordinates of a road segment using QGIS?

I add my own road vector data on top of Google map using open layers plugin with QGIS. The vector layer is generated using PostgreSQL DB. Is there any way to extract coordinates of a road segment ?
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47 views

How can I import layers into a database?

According to the QGIS User Guide (release 1.8.0, page 203/204) I only have to drag a layer from the QGIS Browser to the DB Manager. But for me this does not work.
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3answers
162 views

Postgres geometry in a pdf file with php

Is there a way to draw a postgres geometry in a pdf file using a php script? Thank you.
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1answer
181 views

Rendering order of layers in QGis libraries

I am using the QGis libraries in a external Qt App. When adding vector and raster layers (in any order) to the QgsMapLayerRegistry instance, it somehow sorts the layers so that the vector layers is ...
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1answer
105 views

How to copy a layer in TileMill?

I've been learning to use TileMill, and I want to be able to copy a layer. I especially want to copy layers connecting to an SQLite or PostGIS database in order to avoid having to type in multiple ...
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4answers
1k views

How to merge 48 separated US States layers into 1 layer, using MapInfo?

They are Census Block layers. The person on the website separated them into states so they can be download easier. I uploaded each states separate layer into MapInfo. Now I need to merge the files ...
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1answer
510 views

How to resolve error “Handle bad layers” in QGIS?

I'm new to QGIS and have been seeing what it can do for me – seems good. I imported shape file data from a UK Ordnance Survey data file and saved the file in a new folder. It was very good, doing all ...
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0answers
264 views

How to load the default layer style from Postgresql with Python?

I would like to write a python macro that upon opening my QGIS project file will reload the default style for each layer from the postgres 'layer_style' table. I have had a look at the documentation ...
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1answer
185 views

How can i select many rows from a table?

I want to create an action that select many rows from PostGIS table to show many lines in QGIS. How can i select many rows from table with python to add these rows in a layer? Thank you
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1answer
217 views

How do I style lines to show gradient colors for two attributes?

I have a layer with the city streets. I have a database with traffic values, including traffic going into the city and traffic going out from the city. I need to show the street links with different ...
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0answers
304 views

calculate total Miles in a polygon using Google Map

I have an application that allows the users to create any custom polygon layer on top of google maps, i am interested to know if their is a way to select the road layer in this polygon and then ...
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1answer
2k views

Adding time enabled layers to ArcGIS online

I am trying to add time enabled layers into ArcGIS online. The information in the ArcGIS resource center makes it sound like it is possible to add time enabled layers from ArcMap to ArcGIS online. I ...
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0answers
139 views

“could not get any sources: no image returned from source WMS” error in mapproxy demo

I am trying to connect my mapserver to MapProxy. First part of the map file is shown below MAP FONTSET "fonts.lst" IMAGETYPE png MAXSIZE 4000 SIZE 800 800 EXTENT -20000000 -20000000 20000000 20000000 ...
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0answers
209 views

Adding multiple layers to Tilemill from a single sqlite DB

This is a repost of a question I had over at the MapBox support board. Since I wasn't having much luck over there, I'm hoping I would have better success here. I'm having trouble adding more than a ...
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0answers
283 views

Handling “bad layers” in QGIS version 1.9

I'm having a problem every time I try and open any project in qgis 1.9. It will load part of a few layers and then a yellow bar comes up across the top of the map area that says "Handle Bad layers: 23 ...
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2answers
400 views

ArcGIS 10.1: “ERROR 000223: Cannot extract event table properties” when iterating through multiple files/folder

I am trying to convert ~270k csv-files with lat/long-data to layerfiles. The files are split into folders by year, i.e. ~30 folders with ~9k csv-files in each. I have written a script to iterate ...
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1answer
3k views

XYZ Layer in Open Layers has Missing Tiles

In Open Layers I'm having a missing tile problem where it generates a missing link icon and a pink background. I found several threads including this one saying to add this code ...
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1answer
166 views

Openlayers Overview - disappearing layers

when I do this: var options = { autoPan : true, size : new OpenLayers.Size(300, 200), layers : this.map.layers, mapOptions : { allOverlays : true ...
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1answer
573 views

MXD Performance - number of layers vs number of datasets

My mxd currently has 5 buildings layers accessing 5 different buildings datasets (one for each of 5 counties). Most often there would only be a single county's buildings in the current view, if that ...
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0answers
95 views

Create Layer including drawing objects

I draw some polylines on map. How create new layer with this features? Map and Polylines must be in different layers. public void DrawPolylineUsingInputGeometry(IActiveView activeView, ...
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1answer
120 views

In QGIS can I show just the lines in a Postgis query? How can I do that?

I have three tables in Postgresql, each table with one layer of lines. I want to show the path of an initial line to another final. Is it possible executing a SQL query? Thanks My three tables are ...
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1answer
192 views

Performing a field calculation affects selectable layers in ArcGIS 10.1

In ArcMap 10.1 I have a table open for a layer that I have set as not selectable. Yet when I use the Field Calculator for a record(s) in that table, it automatically makes the associated layer a ...
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0answers
225 views

How can I move two layers at once in QGIS?

I'm trying to move two digitized layers, one containing points, the other polygons to a different location at the same time. QGIS doens't seem to allow this. Even if I select both layers and features ...
2
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1answer
116 views

Join attributes by date in Qgis

I learned (thanks!) to use the join feature built into the layer properties, but in my case it doesn't work because data do not match perfectly. Infact shape refers to geotagged photos, csv is a log ...
2
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1answer
315 views

Using multiple LayerIDs in a Legend

This should be simple, but I cannot find any documentation on how to do it. I have a legend that is bound to my map that contains several layers. I do not want all of the layers to appear on my Legend ...
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2answers
3k views

Some Help to select some features from a vector layer

I have a vector layer (kml) that has some point with scientific name of plants and animals, some description of the place where the people saw them and the coordinates. Basically the table associated ...
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0answers
74 views

proportion of image layer in OL

I tried create map with single image used OL. But I have a trouble: image in map has a wrong proportions. Img: 1540 x 1481 Img in map: 2858 x1481 My js code: $(function (){ var map = new ...
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1answer
58 views

geoserver returns incorrect number of points when cql used

I'm using Geoserver 2.2.4 to support WMS queries. All testing is done via the "Layer Preview" page. If I send a request with no CQL a map full of points is returned as expected. If I add a CQL ...
2
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2answers
557 views

Managing a large number of layers in OpenLayers/GeoExt and Geoserver

I am building a web application to facilitate the handling of approximately 2500+ historic maps. I think it would be too difficult for our users to search for specific maps in an ordinary layer tree. ...
4
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3answers
7k views

How to get the layer name?

I am using OpenLayers, Geoserver 2.1 CQL language. The problem is that I do not know how to address the layer. I am trying to call a function like this: var createWmsLayer = function(name, url, ...
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1answer
778 views

Feature Layer Selections

I'm new to arcgis and arcpy, so some of my lingo and terminology may be off. I have a script that takes a feature layer as an ainput. From there I want to be able to count the number of selections in ...
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1answer
157 views

What ArcGIS Online feature layer can I use to display European states with unique country codes?

I'm writing a web page to display ECB statistics on an ArcGIS JavaScript API-based web map. I'm a bit lost when selecting a feature layer so that I can use the UniqueValueRenderer to make the states ...
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1answer
2k views

How to manage user privilege on layers to Arcgis 10 Desktop?

Problem: I am a Computer Analyst on a town hall. Here we have the sector A and B. Both work in ArcGIS 10 Desktop. The sector A has granted to access/edit everything. The sector A has all the ...
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1answer
115 views

How can I create a button to add a POI layer?

I am making a map of a city with openlayers. I have the shapefile data of the POI (hospital,bank,school etc.) I want to add the layers with buttons not in layerswitcher. Like whereis.com's quick ...
2
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1answer
409 views

How to realign (PostGIS) layers in QGIS?

I'm trying to realign layers in QGIS. As you can see here, the "background" light-blue layer is not aligned with the top layers. I'm working with pgAdmin III and importing PostGIS Layers in QGIS. My ...
5
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2answers
2k views

Create multiple vector layers by reading a GeoJSON file once in OpenLayers

I am a begginner to OpenLayers, and my question is about making things more efficient. My work is about displaying time-dependent weather elements on several point locations on the map. All these ...
5
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1answer
1k views

Export each layer in map to a separate image

I have a mxd file with multiple layers I have to export to PNG/JPG. I would like to create a script which turns on layers one at the time before they are exported. So far I have come up with the ...
2
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1answer
115 views

Keeping a vector layer always on top

I want to know how to keep a layer always on top of other layers! After adding a vector layer ( QgisInterface->addVectorLayer ), I want that layer to always be displayed on top of layers added later. ...
2
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2answers
1k views

Why am I unable to publish a postgis layer to geoserver?

I left arcgis and microsoft sql and now I am trying to connect Qgis+PostgreSQL (PostGIS) + GeoServer. I've brought my postgis database to the server, created a "store". And now I'm trying to publish ...