On a map, a closed shape defined by a connected sequence of x,y coordinate pairs, where the first and last coordinate pair are the same and all other pairs are unique.
1
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4answers
164 views
Counting road intersections and blocks
I have a shp file that consists of the road system of Mexico City. I would like to count the number of road intersections (crossings) and blocks (which I would define as a segment starting from one ...
1
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3answers
333 views
How to calculate forest area of a bitmap (jpeg) map?
I have a map of 1:50,000 scale map in .jpg format. Can i calculate the land area of forest,lakes etc from arcmap.Anybody can give me the step to do it? And I want to know what is the coordinate ...
1
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3answers
211 views
Is it possible to make a routable graph from Polygons?
I would like to know if it is possible to make a graph with pgrouting 1.05 on polygons. What I mean is that I have to make a graph on a database without roads but with polygon geometry. I would like ...
1
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5answers
2k views
How to determine if a polygon is self-intersecting using either ArcPad 8.0 or ArcMap 9.3.1?
I am try to automate a sync replica mxd a nightly basis. The issue I am running into is that in some the of the AXFs (that I get from the users and check-in) have polygons that are self-intersecting ...
1
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3answers
196 views
How to auto fill or delete sliver polygons without losing precision?
I am developing some boundaries in which precision holds the key value.
Using ArcGIS 9.3 I am converting lines to polygons using the "feature to polygon" tool. The lines are accurate but I find ...
1
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2answers
275 views
Assign unique ID to each polygon
I feel like this should be really simple and I am missing something. All I wish to do is assign a unique ID to each polygon since I have multiple identical FID values. In MS excel I would simply type ...
1
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4answers
2k views
Sum of areas in all each polygon layer?
I've got several layers/feature classes in an ArcMap 10 project.
Thanks to everyone's help, I'm able to get the areas for the polygons contained within each layer.
By opening the attribute tables ...
1
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1answer
37 views
Polygon to fill gap
Using postgis I want to fill a gap between other polygons.
Can you help with some directions what functions to use ?
Thank you and sorry if the question is rather noobish.
Image to explain from ...
1
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1answer
143 views
arcpy points in polygon check
I have a list of points and a list of polygons both in a separate shape files. I am trying to write a ArcPy script to loop through the points, and then the polygons respectively and tell me when a ...
1
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1answer
255 views
How to convert a polygon to a grid of polygons using QGIS?
For example, the city of Rotterdam represented as a hexagonal grid.
1
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2answers
205 views
Label inside top left corner of polygons
Does anyone know of a tool or procedure to automatically place a label in the corner of a polygon, rather than at the centroid?
I am using Mapinfo and know that I can manually place the label ...
1
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2answers
69 views
How to add a polygon from GeoJson into Leaflet?
I try to use the following function to add polygons to my Leaflet map.
function polygon(geojson)
{
alert(geojson); // alert for testing
layer = L.geoJson(geojson);
layer.addTo(map);
}
...
1
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2answers
88 views
Dissolve polygons - group to others with touching corners
I am working with some data that shows land management. There are many places where corners "touch". I would like to dissolve my dataset so that features are grouped (dissolved) with those that they ...
1
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2answers
240 views
count features in polygon shapefile A that fall within each feature of polygon shapefile B
I have two polygon shapefiles, each of which contain multiple (possibly overlapping) polygons.
Is there some way, using GRASS, to calculate the number of polygons belonging to shapefile A that fall ...
1
vote
2answers
208 views
Clip raster to multi raster
I have a raster aerial photo. I have county wide parcel data.
I want to clip/screen shot the raster at each individual parcel.
Think of this application - a post card with an image of your house ...
1
vote
1answer
46 views
Polygon Nodes do not have separate coordinates [duplicate]
I'm attempting to measure the distance of a series of points from a smaller number of polygons. As a first step, I've changed the polygons into points along their border, via the
Vector> Geometry ...
1
vote
2answers
281 views
Openlayers remove previously drawn polygon on starting to draw next one
Objective:
At any point of time there SHOULD only be zero/one polygon(s) on a vector layer with a polygon control. I need the previous polygon to be removed as soon as user starts drawing the first ...
1
vote
1answer
89 views
Why is ArcMap 10.0 editor deleting some added vertices and simplifying polygon?
I am using ArcMap 10.0. I am trying to edit (and add) vertices in a polygon.
I start editing, (using "Edit Vertices" tool), and add many vertices in the polygon.
Then when I am done, I save the ...
1
vote
2answers
177 views
One Polygon Joining to Database with Many matching records
Using ArcMap 10.1.
Is this possible to have one polygon and join to a database/excel with many matching records?
I would like to have 1 polygon but match to 100 corresponding records in a table. When ...
1
vote
1answer
103 views
What is the Quickest Way to Update Polygon Geometries in ArcGIS
I have a shapefile which contains the approximate boundaries for sites that are being worked on (thousands) in polygons, each with a reference number and additional detail in the attribution.
I have ...
1
vote
3answers
1k views
How can I aggregate points to polygons?
I am trying to aggregate my data points to the polygons so
that I could find out how many points I actually have in
each polygon, and then export the data contained within
each polygon to further look ...
1
vote
1answer
276 views
I wanting to reproject the vertices of my polygon. I have been able to achieve this for the bounds but having a bit of trouble with the vertices
I wanting to reproject the vertices of my polygon. I have been able to achieve this for the bounds but having a bit of trouble with the vertices.
function onFeatureModified(event) {
...
1
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1answer
405 views
Unproject Radius with Openlayers with CRS:84 Projection
I have made a Openlayers integrated map that lets you draw a circle, On completion of the circle I have told the map to give me , Bounds, Center Long and Lats, and lastly the radius. My problem is ...
1
vote
1answer
800 views
merging 2 polygon adjacent to each other using R
I have several shp files which are the components (or tiles) of a map, I have joint all these tiles together to have a large shp file. Then I realized some of the polygon is now splitted into 2 ...
1
vote
1answer
260 views
Highlighting and exporting raster layer based on vector polygon
I am a Quantum GIS beginner. I have a set of adjacent polygons in a vector layer that is overlaid on a raster layer of OS StreetView OpenData. I want to be able to select each of these polygons and ...
1
vote
1answer
30 views
How to get polygons from PostGIS table to PHP array best?
Currently I fetch polygons from a database table using ST_AsText(). The results are in text format, like the following.
POLYGON((84 104,212 48,321 122,243 179,275 238,131 240,84 104))
I am not ...
1
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1answer
80 views
How to convert a shapefile polygon to raster in C#
Does anybody know a way to convert a polygon (vector) in a shapefile to raster data WITHOUT using ArcGIS Explorer Desktop? Is there a way to do this 'progmatically' in C# (WPF with ArcGIS runtime ...
1
vote
3answers
263 views
How to create one KML per polygon (from one Shapefile)?
I have a shapefile containing hundreds of polygons. I need to create a kml of each of the polygon. Is there any way that I may not have to deal each polygon individually and my polygon file may give ...
1
vote
2answers
120 views
information from a shapefile to another shapefile
I am very new to GIS and learning by myself so what I'm about to ask is possibly quite basic.
I am using QGIS.
I have a shapefile, which categorizes areas (land cover) by numbers (corresponding to ...
1
vote
1answer
345 views
QGIS, how do you break segments of a polygon, ie break 1 polygon into 2 or more?
I have a polygon but would like it to be in broken up to put into different layers. I can't work out how to do this.
1
vote
1answer
131 views
gdal_rasterize -at function still won't capture covered pixels properly
I'm currently using the gdal_rasterize tool in bash. My code looks like this:
gdal_rasterize -l $(basename $file .shp) -burn 1 -a_nodata 0 -te -180 -90 180 90 -tr 0.1 0.01 -at -ot Byte $file ...
1
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1answer
97 views
Summarize polygon area using another polygon
I have a shapefile representing public/private lands in Montana. This is a multipart shapefile where I've simplified attributes so that #1==private and #0==public.
Next I have a shapefile of ...
1
vote
3answers
189 views
How to create a generalized polygon layer from a raster?
I have a tiff file where I have extracted vegetation in a height interval from LIDAR. At the moment the picture is kind of blurry with no data cells between vegetated cells. I would like to create a ...
1
vote
2answers
69 views
How to query points that fall outside their designated regions?
I have a shapefile with 250 points. Each point has a region attribute. In another shapefile I have all the possible regions with their names (it is polyline geometry).
Unfortunately the coordinates ...
1
vote
1answer
140 views
How to identify Polygon within another Polygon layer
I have two polygons files. The first one has several smaller polygons within it eg.a shapefile with all US states, the other polygon file has a single polygon eg. a river basin. I am trying to get all ...
1
vote
2answers
309 views
How to combine “positive” with “negative” polygons
I have 2 polygone classes (1 and 2). Inside the polygons are holes (white). Now I want to combine them with the polygon in witch the holes are. Understand? Sorry for that bad english...
The white ...
1
vote
1answer
397 views
How to color markers based on polygon area?
I have a map with around 317 markers and each marker is the center point of a polygon. The polygonal area varies throughout, so I want to represent the markers in such a way that the polygon with the ...
1
vote
1answer
305 views
Aggregate Data between Polygons
I have data at the ZIP3 level and I need to join it to a state file. I also need the data within the zip3 file to be averaged, but for some reason when I use the join tools, i'm not getting the ...
1
vote
2answers
623 views
Openlayers Vector Layer Polygons not displaying properly with OSM
So I have an Openlayers map displaying Acetate tiles in OSM, and I'm drawing polygon regions on a vector layer to represent the countries of the world. This works fine for the most part, however, ...
1
vote
3answers
66 views
Openlayers vector feature coordinates are not transforming,
I have a OpenLayers vector with a single feature [0]. It's coordinates are in the map projection (EPSG:3413) and I want them in WGS84 (EPSG:4326) decimal degrees. I have the following code which ...
1
vote
0answers
47 views
Are polygons created in Arcpy built in any order?
My script uses a search cursor to evaluate polyline coordinates and build polygons based on those coordinates. The script works well, but I am curious as to whether anyone knows the order (if there ...
1
vote
0answers
69 views
Line to Polygon via Polygonizer in QGIS
My question is in the same vein as this one.
I'm attempting to convert precipitation lines (Precipitación Media Anual) to a polygon for Mexico in QGIS using the Polygonizer plugin.
After running the ...
1
vote
0answers
60 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 ...
1
vote
0answers
39 views
graduated pattern polygon fill
I'm sure this question is really really basic but I appeal to you because I hate the idea that I have spent 20 minutes trying to do such a simple thing...
All I want to do is style a polygon layer by ...
1
vote
0answers
39 views
Avoid rounding of coordinates in pyQgis
If I get the coordinates of a polygon in qgis by
x = geom.asPolygon()
It rounds off the coordinate from i.e.
-27,200,334.86
to
-2.72003e+07
How can I avoid that?
1
vote
0answers
53 views
Is segment of polyline contained in polygon
I am pretty new to arcpy and am slowly learning all its functions. I have a scenario where I am traversing a polyline. I get a start point and an end point on the polyline and form a segment with ...
1
vote
0answers
26 views
Suggestions for vector format for polygons
I am using two polygon tables in postgis (A and B ).
I need to make a vector file that incorporates information of the overlapped polygons B intersecting each polygon on (A).
I can make a single ...
1
vote
0answers
50 views
When digitizing, objects are not saved well
I've some problems with digitizing.
If I draw a line or a polygon, the line or polygon is saved in the attribute list, but not visible and its location is not saved either (when I zoom to the object ...
1
vote
0answers
308 views
Calculate polygon area inside extent
We're using ArcMap 10.0 sp5, creating a tool in c# using the ArcObjects sdk.
Is there a built in function or simple set of steps that calculates the area of each feature of a polygon layer within a ...
1
vote
0answers
45 views
Add regular points to each polygon in QGIS [duplicate]
Possible Duplicate:
assign and move centroids to their polygons
I'm trying to find out a method to define a unique ID based on specific coordinates for each polygon of a shp. The problem is ...
