0
votes
2answers
34 views

Polygon Data to Fit Raster

I'm working with an NHD Flowline of streams and rivers in NC, and I'm trying to only retain the ones in the raster. I tried to convert to the raster to a polygon and was going to clip them, but in the ...
2
votes
4answers
260 views

QGIS Polygon precision

I have a fairly straightforward question; is there a way to edit the precision of polygon points in QGIS so that each coordinate has the same number of decimal places? For example, the coordinate ...
0
votes
1answer
49 views

Converting an Experian (Geoconcept) file to GPS coordinates

I'm working with a file containing Experian data which was used in Geoconcept. The file describes a serie of microzones, that is polygons. Unfortuntely the coordinates system is hard to understand: ...
1
vote
0answers
175 views

How to Smooth Polygons after converting DEM using Raster to Polygon?

I have a DEM SRTM that I classify using Spatial Analyst Tools > Reclass > Reclassify. The result is box shaped so I go to Layer Properties > Display and choose cubic convolution. The result is ...
3
votes
2answers
489 views

How to convert polygon layer to txt files?

Is there any way to convert polygons that do not have coordinates in the attribute table to a txt file with coordinates. I will be using the txt file in a different software (not ArcGIS), so I need ...
5
votes
2answers
630 views

How to enclose clustered points with polygon?

I have a raster with forest (1), no forest (2) data. "1" is represent single/few trees and there is gaps between them. I want to create a polygon around these trees to a forest map. It is not a dense ...
3
votes
3answers
841 views

Finding centrelines from polygons?

I was wondering if there is a way to create centre lines from polygons in QGIS? I have a polygon layer, but ideally need the centrelines as a separate file. Thanks, Alan
2
votes
1answer
643 views

Convert shapefile in NAD27 from meters to decimal degrees to match xy data?

I have a shapefile of a boundary (polygon) that has the following projection: NAD_1927_UTM_Zone_11N Projection: Transverse_Mercator False_Easting: 500000.00000000 False_Northing: ...
6
votes
4answers
4k views

How do I convert a polygon into a point?

I want to convert polygons into points. I know how it's done in ArcGis and I think this may sound trivial but it's a serious issue :/. I'll appreciate any hints :)
4
votes
2answers
457 views

Is it possible to generate a vector polygon from a polygon on a raster image?

I have a raster map which I have extracted from a government report providing flood extent return frequencies. I want to 'snatch' these flood extent polygons (i.e. convert to vector) and I was ...
13
votes
2answers
1k views

How can I fix my complex Polygons so they show correctly in Google Maps?

Problem: I'm trying to find a way to fix some broken polygon shapes and I'm not sure how I can do this. Details: I've got a number of polygons which I basically imported from TIGERLINES a while ...
6
votes
1answer
4k views

How to convert a String to OpenLayers.Geometry.Polygon using javascript?

First let me say that I'm using Javascript, jQuery, Java, GeoServer, OpenLayers and PostGIS. Using java class ResultSet I return this String: POLYGON((516000 2135000,515039.264020162 ...
4
votes
1answer
2k views

Convert shapefile lines to a polygon in GRASS

I have a shapefile of a map that is the outline of a number of islands. I would like to convert the lines into polygons (ie all islands filled in) using GRASS. I searched on how to do this with GRASS ...