Tagged Questions

(1) abstract geometry; (2) storing geographic data in projected coordinates; (3) a generic ESRI term for vector features; a class for "geometry" objects.

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3
votes
2answers
1k views

How do I get that polygon from Javascript ArcGIS API?

I would like to have a user draw a Polygon (or Line) onto a web map with the Javascript ArcGIS API drawing tools. For the life of me I can't figure out how to pull that polygon from the client and get ...
2
votes
2answers
175 views

Is there Shape Metrics Toolbox or equivalent for ArcGIS 10?

I need to compute the geometric properties (e.g. contiguity index, dispersion index etc.) of a series of polygons and I would like to use the Shape Metrics Toolbox. I am using ArcGis 10 and the ...
0
votes
0answers
145 views

several fields and GEOMETRY GetFeatueInfo from Geoserver

Good day!. I have a table in PostGIS 2.0 with several fields of type GEOMETRY. In the geometry_columns they are published in Geoserver 2.2 as layers. This is done as here - geoserver docs, but ...
0
votes
1answer
65 views

How can I transform geometry data to bounds?

My SRID is 3137 and I want to transform geometry data(e.q : "0101000000904160258CC91841C8073D6723545141") to bounds. I need to bounds coordinates for use in maxExtend() function. Help me please!
2
votes
1answer
351 views

Combining polygon geometries with python and QGIS segfaults

I am trying to combine polygons, using Qgis 1.8, and every time I run this script in the python console, I get a segmentation fault. Here is the script: from PyQt4.QtCore import * iface = ...
0
votes
1answer
179 views

QGIS Python - Convert geometry from Postgres to QgsPoint()

I have made a query in Postgres to get some points to use with python. This points are in geometry data. How can I convert that geometry in decimals to use QgsPoint() in python? Thank you
1
vote
1answer
513 views

Intersection with JTS Geometry

I want to calculate an intersection between two geometries with the intersection function from JTS Geometry. What happens, if the geometries have different SRIDs? SimpleFeature sf1=...; //SRID ...
1
vote
0answers
97 views

Python GDAL/OGR: check lines geometries connectivity

I'm working with shapefiles representing roads, so basically it's stored as (poly)lines. I need to perform a road connectivity checking. In other words, I want to ensure that roads meant to ...
2
votes
1answer
490 views

How to get point x and y geometry from a shapefile?

I have a shapefile of US Cities and I want to get the X and Y coordinate of EACH city in that shapefile. I've tried this: for city in city_cursor: geom = city.Shape point = geom.getPart() ...
2
votes
1answer
866 views

How to write point geometries with arcpy instead of gp syntax?

Can someone help me fix some code that simply writes points into a featureclass? It used to work in the older gp. syntax, but I'm having difficulties rewriting it in arcpy for ArcGIS 10.0. In this ...
1
vote
1answer
140 views

How to fix buffer selection issue in ESRI ArcGIS Javascript API and LGIM applications

I had strange LGIM application behavior where the map spatial search did not highlighted the parcels within the Geometry Buffer. What could be the possible reasons? LGIM stands for the Local ...
2
votes
1answer
196 views

How to modify the coordinates of a SHP geometry using Geotools?

I have a shapefile with some polygons. I would like to change the height for this elements using Java. The rest of the attributes should be the same. I've thought using GeoTools but I haven't found ...
2
votes
1answer
176 views

Calculating area [closed]

I have a polygon layer. I toggled to edit mode. I added a new column, while number (integer) and called it "area". I then use the field calculator - geometry - $area to populate the polygon area for ...
14
votes
3answers
2k views

How to find the maximum-area-rectangle inside a convex polygon?

In this post we are looking for algorithms / ideas on how to find the maximum-area-rectangle inside a convex polygon. In the following figure, numbers are the areas of the fitted rectangles. As shown ...
2
votes
3answers
224 views

How to test if geometry is inside another?

I need to tell whether geometries from a shapefile are inside other geometries or not. For example, I want to test if there are trees (represented as points in trees.shp) inside the urban areas ...
1
vote
3answers
312 views

Merge Multipart Feature Line

I'd try to merge multipart feature line, but didn't work. would you please teach me how to merge multipart feature line? I work in version environmental and geometry network. Regards,
3
votes
1answer
147 views

How can i topologically sort 2D triangles and put in an array?

I have a set of 2D triangles in a Geometry array which together forms a connected strip when placed them according to edge adjacency. However, in the array they are not in topological order based on ...
1
vote
1answer
122 views

Postgis invalid geometry from shape file

I'm having trouble converting a Feature class (shape file) to a DB table (Postgresql 8.4/Postgis 1.5). This is the command in the pg log: INSERT INTO "public"."distritos" ("Shape" , "DEPARTAMEN" , ...
4
votes
0answers
246 views

What traits identify 2D, 2.5D, 3D geometries, and how can you convert downward, such as from 2.5D to 2D?

In answering this question, posed by @Burton449, I came to realize I don't have a definitive grasp on what distinguishes 2D, 2.5D, and 3D geometries. I certainly realize Z/elevation values are ...
0
votes
1answer
194 views

ST-Links convert Feature Class to DB Table error

I'm using ArcMap with the ST-Links SpatialKit Conversion tool to convert a Feature Class to a DB Table. But I'm getting an error: ERROR: 42601: type modifier is not allowed for type "geometry". I ...
3
votes
1answer
384 views

Reading OGC geometry data from SQL server using R

I would like to write a script in R that creates a map using OGC geometry data that is stored on a Microsoft SQL server. Is there a way to read OGC geometry data using a query passed from R? Maybe ...
2
votes
1answer
512 views

Can you explain this WKT multipolygon format?

I am confused by the output I'm getting from ogr2ogr when converting a shapefile to WKT. What I'm expecting to see is something in the form below (from Wikipedia): MULTIPOLYGON (((40 40, 20 45, 45 ...
0
votes
2answers
263 views

Calculating area gets a different result

I've calculated the area of polygons with QGIS by using ctr-i - geometry - $area. I've set it on real. The results seem fine, but I've noticed they differ from the area given when I use the ...
3
votes
1answer
5k views

Making POINT from longitude/latitude coordinates in existing table using PostGIS?

I would like to make a POINT using the longitude and latitude columns of an existing table. Here's a link to the documentation of ST_MakePoint. Here's my table: CREATE TABLE sysinst.bio ( oid ...
2
votes
1answer
535 views

How to split zAware polyline by points programmatically with C#?

I'm trying to split a polyline by the boundaries of a polygon using IPolyCurve2.SplitAtPoints using C#. The polyline I'm trying to split is zAware and holds elevation values at a regular interval. ...
0
votes
0answers
67 views

How to populate polygon extents to an attribute table in QGIS

Is there a way to calculate the XMIN, YMIN, XMAX and YMAX of a polygon and write it to a field in an attribute table? The Geometry functions available in the Field Calculator are for points. ...
2
votes
1answer
109 views

Which is better for storage? Geometry column or varchar?

Objective: Need to store and retrieve a list of geometries from the database. Basically these are drawn by the user using OpenLayers which I would like to save and present again as a list (kind of ...
0
votes
0answers
73 views

Retrieving ArcGIS:s Spatial Data into a Database

Background: If you have created a vector map with lots of spatial data in geometry flat in with measurement kilometer. The following object that is used in the map will be point, line and polygon ...
0
votes
1answer
106 views

Is it possible to have measurements in centimeter and decimeter in 2D flat (geometry)?

Is it possible to have measurements in centimeter and decimeter in 2D flat (geometry) for ArcGIS?
3
votes
1answer
91 views

Find gap in / endpoints of linestring

I have a set of features of type linestring. I'm trying to polygonise the linestrings and assumed that they were closed (naive me :) ). Of course some were not closed and I'm trying to locate the gaps ...
2
votes
2answers
159 views

Programmatically change geometry column in OpenLayers WFS layer

is there a way to programmatically change the geometry column on which a WFS layer is based and displayed? WFS (from GeoServer) is correctly returning me two geometry columns, I want to change "on ...
3
votes
2answers
533 views

arcobjects update geometry Z values of line vertices with a given number

I am trying to develop arcgis 10.0 addin to update Z values of vertices of a selected line. Scenario: The tool scans all features in a given shape file and populates the list of features which has at ...
3
votes
4answers
419 views

What Application for Vector and Cartesian Coordinate System

Goal: Visualize a picture in SQL server 2012 spatial data based on geometry Problem: In order to display a vector picture I need to retrieve X, Y coordinate (cartesian coordinate system) and ...
1
vote
3answers
137 views

How to Retrieve X and Y from a papermap or gif picture

Goal: Visualize a subway map in SQL server 2012 spatial data based on the map of the subway. The map shall use geometry, traffic rail road as line object, station as point object and zon as polygon ...
4
votes
2answers
366 views

PostGIS algorithm to unite points of two geometries that are within specified radius

I want to find an PostGIS algorithm to unite points of two geometries that are "near" to each other. That is: I want a function, that takes as input two geometries, and returns 1 geometry, that ...
4
votes
2answers
3k views

How to calculate distance between two points with esri.geometry?

The function http://help.arcgis.com/en/webapi/javascript/arcgis/jsapi/#namespace_geometry/esri.geometry.getLength should calculate distances between points. When I am trying to calculate distance ...
1
vote
0answers
115 views

Geoprocessing operations re-introduce geometry errors after “repair geometry” succeeds

I am working with a shapefile that has many small, detailed polygons. After exporting it to a feature class in a geodatabase, I found that some operations (for example, Snap in the Editing Toolbox) ...
0
votes
1answer
609 views

how to find vertices for a geometry in OpenLayers

I am having a LineString, where I need to find the vertices logically and save those vertices. Can anyone help me out. Or else how below can help me. OpenLayers.Geometry.LineString = ...
2
votes
1answer
376 views

Geometry valid in PostGIS turns out to be not valid in Oracle

Geometry is in PostgreSQL database. It is valid. Geometry is exported as GML and then inserted into Oracle database. Then function SDO_UTIL.RECTIFY_GEOMETRY(geometry, tolerance) is called, which ...
2
votes
0answers
71 views

Critera for geometry or geography

What criteria do you need to take account to before you choose geometry or geography map? Is there a book or page about it?
3
votes
1answer
499 views

Geometry Conversion Problem

How do I convert from an ESRI.ArcGIS.Geometry.IPoint to an ESRI.ArcGIS.Client.Graphic point object? In other words, I'm wanting to convert from an IGeometry to a runtime geometry, I guess.
3
votes
2answers
243 views

Several questions about using spatial data?

If you have spatial data for SQL server, can you use the spatial data (both geometry and geography) in another application for instance ESRI ArcGIS? Is spatial data a standard that every GIS ...
3
votes
2answers
534 views

Visualize Spatial Data in Reporting Service

Is it possible to visualize a piece of geographical map from SQL server Spatial data (geometry, not geography) in a report from reporting service? If yes, how should it be done in a course of action. ...
5
votes
0answers
192 views

Why do file geodatabase and SDE readers produce different fme_geometry types?

I have one very simple workbench that I am running against both SDE (9.3) and FGDB (10.0) sources. I noticed two different fme_geometry values for same type of objects. For the first one, i.e SDE ...
2
votes
3answers
628 views

arcpy: get list of adjacent lines per line

I am working with polylines with hundreds of thousands of features, and would like to write a script that returns the OIDs of all lines adjacent (intersecting with) each line. I have been ...
4
votes
1answer
558 views

How to find the nearest polygon from a given point?

Basically I have set of points [lat-long pairs] which defines different polygons on map. Now I have a coordinate [lat-long] from which I want to find the nearest polygon from that point. Any help ...
8
votes
2answers
1k views

Nearest point on a line ( Spherical / Mercator projection )

I have a line (Ax,Ay - Bx,By) over a mercator projection (google maps) and a random point (Cx,Cy) nearest to that line, i would to know the closest point (transparent blue on the image) over that line ...
13
votes
5answers
411 views

What in-depth spatial database systems tutorials exist?

Is there a good tutorial that explains in depth the internals of a GIS and a spatial database system such as PostGIS with examples and without any background assumption? I'm specifically looking for ...
5
votes
1answer
109 views

Should the geometry column always be the last column of a postgis table?

When we need to add an attribute to a table (e.g. a table of 350,000 polygons), my instinct is to always recreate the table so that the geometry column is last. I think this is a best practice for ...
1
vote
1answer
316 views

“There is not enough memory” Error when accessing IArea.LabelPoint

I have an intermittent error that I'm having a terrible time tracking down so I thought I'd see if anyone has encountered something similar. I am trying to access the label point of a polygon feature ...