All Questions

3
votes
1answer
53 views

Shapefiles - Polygon type - is it in fact multipolygon?

I'm wondering about the ESRI shape file with shape type 5. When reading the spec I see that "A polygon may contain multiple outer rings.". Does this mean that these outer rings must be combined to ...
0
votes
1answer
10 views

How do I view ovl files on Geogrid or Top50 then convert the data to shapefiles?

I have some .ovl files which can only opened on Geogrid or Top50 viewer which shows me where everything is. How do I take these ovl files and convert the properties to Shapefiles to be used on ArcMap ...
0
votes
1answer
15 views

Python OGR Geometry changes Floating Points

I'm creating a Polygon in OGR and adding coordinates to it in Python. It is a must that my coordinates aren't allowed to change when adding, however they do and I don't understand why. Here is my ...
0
votes
1answer
9 views

Table Of Content widjet in arcgis javascript api

I'm using TOC widjet in my application using arcgis javascript api, it is working, but the problem is that the plus and minus images which collapse or expand the tree is not appearing. I noticed ...
0
votes
0answers
21 views

Web map survey/questionnaire

I have implemented a new web map application in my organization and I want to do a survey/questionnaire for the web map users (both internal and external users) to collect information about what they ...
1
vote
0answers
23 views

Create a “wide” table recording all overlaps between polygons in PostGIS

I have a set of overlapping polygons and would like to record which polygons are overlapping at each intersection. I have followed the instructions at: ...
0
votes
0answers
17 views

How to create a 8Bit unsigned geotiff with gdal?

I'm trying to create a 8 bit geotiff with this code. Is there a way to use unsigned 8 bit? I only found the GDT_UInt16? import numpy as np from osgeo import ogr, osr, gdal from osgeo.gdalconst ...
3
votes
2answers
46 views

How to fill sinks in DEM with specific amount of water

I identified the sinks in my terrain based on the DEM (grid) by using the 'fill'-tool and substracting the original DEM from the filled DEM. I also identified watersheds as well as flow paths. Now i ...
1
vote
1answer
62 views

How to add vertex to an existing polyline programatically?

I have a Polyline and would like to add new vertex to before start point or end point or at any part of the polyline using python in qgis. How can i do that?
2
votes
0answers
6 views

Geoserver SLD scale based view for multiple geometry styles

I have a FeatureStyle that draws line and adda an arraow to end point of the line. And I want to see this line and arrow by scale. So I specified a MaxScaleDenominator property. Now line is not ...
0
votes
0answers
8 views

How to read Spatial Data File (.SDF) in C#

Using the Mapguide .NET C# API (with FDO API) i would like to reads sdf and creates a shapefile out of it. So basically take sdf as input source and create a shapefile out of. please suggest me ...
0
votes
0answers
27 views

mapserver and openlayers3 - map not displaying properly

After literally 20 hours of banging my head against the wall without success, I'm hoping that my issue is a trivial syntax error or perhaps something obvious to somebody who knows more than myself ...
0
votes
1answer
14 views

Spplot labels in R how to change

Can anyone tell me how to change the labels in a legend created by spplot in R? It is a typical vertical ribbon legend automatically generated by spplot. Based on color, it is labelled 1-7 but I ...
0
votes
0answers
9 views

Get SHP or SVG from GADM subdivisions within a country (Guyana)?

GADM is a high-resolution database of country administrative areas. I have downloaded the whole world distribution (it is composed of several dBase III files and a big .SHP file). I am trying to ...
0
votes
0answers
14 views

What are the advantages of interpolation vs raster from point elevations?

I want to make a potentiometric surface map. I have a bunch of wells plotted. The way I learned would be to make a raster of elevation of ground surface and another of depth to water and perform ...
0
votes
0answers
19 views

Create Polygon from same triangles [on hold]

I want to create polygon from triangles. I have group of triangles which all have same normal. I want to merge triangle in single polygon. As a source code details, I have one vector of struct. ...
1
vote
0answers
8 views

Avoiding intersections with QGIS Spline plugin (Version 2.0)

Has anyone gotten the QGIS 'avoid intersections' option to work when adding polygons via the Spline plugin? When checking the option and enable topological editing, I continue getting overlaps in my ...
1
vote
1answer
63 views

how to allow null values in a feature-layer

I'm using ArcDesktop 10.2. I have 30 x,y locations that have 20 fields of numeric data, stored in an Excel spreadsheet. Some cells have no data, and I want those cells to be represented as null values ...
1
vote
0answers
21 views

How i can have the same xMin,yMin for vector files in Qgis 2.4

i have a .shp file(polygon) in EPSG:2100 - GGRS87 / Greek Grid and an other .shp(points) in the same system(EPSG:2100 - GGRS87 ) but different xMin,yMin. The first has xMin,yMin 583309.00,4152885.94 ...
1
vote
1answer
75 views

How to convert local Coordinates to lat/long Coordinates

I'm using QGIS to do some data analysis and visualization for my newspaper. I received some x,y coordinates from the City of Minneapolis that I can use to build some static graphical maps shaped like ...
0
votes
1answer
26 views
-2
votes
0answers
38 views

Totaling Population within A Polygon

I am trying to count total populations within several arbitrary polygons using census block data. How can I get a total number per polygon?
0
votes
0answers
25 views

Longitude and Latitude Mixed Up on Map

I am trying to map a WFS layer with data originally coming from a PostGIS table, and using a OpenLayers 3. At some point in this process, I believe the longitude and latitude coordinates are getting ...
0
votes
0answers
4 views

Problems resampling and displaying grid coverages with EPSG 27200 <-> 2193

What is wrong with this code? Given a BufferedImage , a world file and a coordinate system I construct a code coverage as follows: Rectangle actualDim = new Rectangle(0, 0, ...
0
votes
0answers
34 views

Hot Spot Analysis

I'm using ArcMap 10.2- I've got a series of coordinate points, each with an associated value (level of income) that I would like to turn into a heatmap. I've projected the points onto a map, run the ...
0
votes
0answers
9 views

How do I get new world file parameters from a resampled grid coverage?

I have a grid coverage that I resample (reproject) and I would like to find out what the new matrix coefficients that would be outputted to a world file. How do I find them?
0
votes
0answers
11 views

postgis & mapnik “column ”CLASS“ does not exist”

I've piped an osm map of greece into postgis with osm2pgsql and was playing around with C++ mapnik sample code giving "planet_osm_polygon" as the source table: parameters p0; p0["type"] = ...
-1
votes
0answers
17 views

In Excel find and return next value that meets the criteria [on hold]

Have a seemingly simple question that I just don’t know how to fix. These are the excel columns: PointID number result **1 1 2 1 #end resultA (3)** ...
0
votes
1answer
24 views

How to convert WMTS to WMS?

I have a WMTS link which i want to use for my work. The problem is that i cant use it with Autocad Map cause it consumes only WMS, or ArcGIS 10, cause ArGIS 10.1 and above uses WMTS. Is there any ...
0
votes
0answers
23 views

How to define the next object in the street with android?

I wanna put objects in a map and discover which is the closest objet from me, supposing that I'm in a moving car with my cell phone. Thus, to define the closest object I need to take the orientation ...
4
votes
1answer
75 views

Digitizing contour lines from paper maps using QGIS?

Is it possible to give digitized altitude lines (from paper map) heights using QGIS?
0
votes
2answers
35 views

Are there publicly avaiable run-off data for Africa

I was wondering if there are good publicly available dataset for surface run-off (water)? I have a rough idea that surface run-off should be some function of rain-fall and soil ...
4
votes
1answer
63 views

SQL “Case” statement when count(*) is 0

I am trying to write the following SQL command using case clause. with x as (select the_geom as geom from table1 where st_dwithin(the_geom, st_setsrid(st_makepoint(28.959495,41.019913), 4326), ...
0
votes
1answer
25 views

Classifying type of land use each spectral represents from remote sensed data?

How do you know the type of land use each spectral represents from an remote sensed data into a classification ? Which classification is the most typical to use when doing that ? How many ...
0
votes
0answers
14 views

Adding Raster Layer in C++ application always result in layer invalid

I am trying to add a raster layer in c++ application with QtCreator and QGIS 2.6.0. My code is as follows: QgsRasterLayer * layer = new ...
0
votes
0answers
29 views

Understanding the error term

I have some (mobile) location data from a vendor. For each user and timestamp, there are three columns: lat, long, error. I "guess" that the error means that the user is located within a circle with ...
1
vote
2answers
41 views

Calculate nearest feature with a barrier

I have three shapefiles: a) polyline with rivers and streams (also as polygon available to me), b) polylines of highways and roads and c) point file with locations in the riparian vegetation. I want ...
0
votes
2answers
29 views

ModelBuilder and Delete fields

I like to know if there is a solution to the following problem. I currently have a simple ModelBuilder workflow in which includes a list of shapefiles being copied. Within the workflow, once copied, I ...
1
vote
0answers
20 views

Calculate geographic position based on azimuth, distance and height

How to calculate the geographic position of an object in sky (like an aircraft) based on only three variables: Azimuth, Distance from home point and height of an aircraft?
1
vote
0answers
17 views

Interpreting some hydrology data

This is the historical feed of the Keystone dam for October 2014: http://www.swt-wc.usace.army.mil/chartbin/KEYSOct14.shtml Here is the real time feed: ...
0
votes
1answer
28 views

Python buffer in a line using GDAL

I am trying to make a buffer from a line using gdal. I use the example in the gdal Cookbook import ogr, os def createBuffer(inputfn, outputBufferfn, bufferDist): inputds = ogr.Open(inputfn) ...
2
votes
1answer
21 views

area elevation distribution with QGIS

I have a raster DEM and a polygon covering a part of it. I need an area-elevation distribution (i.e. how many m2 are in which elevation interval). 20m intervals will be fine. I cant figure it out.
2
votes
1answer
31 views

Identifying the side of a point from the closest polyline in ArcMap 10.0

I have a set of polylines (a network of streams and rivers) with information on the left and right side of the streams on riparian structure. I also have locations (points) of either side of the ...
1
vote
2answers
25 views

Insert values in Postgresql in Java

Hello i try to insert same values in my table but i write this code String sql = "INSERT INTO points (gid, osm_id, name, type, geom)VALUES (?, ?, ?, ?,ST_GeomFromText('POINT(?, ?)', 2100));"; ...
1
vote
1answer
19 views

Can't recreate missing address locators

My organization uses several address locators stored in SDE. The server license was recently updated, and shortly after, some of these locators simply disappeared -- they are no longer visible or ...
0
votes
1answer
9 views

opening a georefrenced image in IDL in ENVI

I am working with idl in envi,I want to use ENVI_CONVERT_FILE_COORDINATES in case of finding pixel value of specified point,for this porpuse I have lat and long data of my point but I need to open ...
1
vote
0answers
16 views

How do I apply selected features from a output group layer to the same existing group layer?

I am doing a geometric network project, and am running 3 trace process within a model to find connected features to a set location on the network. Each trace function wants to output its own group ...
2
votes
0answers
15 views

Percentage of a polygon at, or less than, a specific height (supplied by a raster)

I am using QGIS to process some LIDAR data. I need to be able to define the area of a pond with respect to its depth (i.e it is 100m^2 at 32mAOD and 500m^2 at 33mAOD). Is there a way of finding the ...
2
votes
0answers
20 views

QGIS returns “invalid layer” when adding a WMS layer

I want to add a WMS layer in my map. I select the server and obtain the list of layers that are published there. I select one of them (the problem is the same with all layers), but QGIS does not load ...
1
vote
0answers
27 views

how to use line feature as stops input in network analyst?

I'm trying to build a certain route with network analyst on a Network Dataset. As an input to create the route I want to use line features. I am trying to do this with network analyst in ArcGIS 10.0 ...

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