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1500 questions
22
votes
3 answers

Do ArcGIS SpatialReference object factory codes correspond with EPSG numbers?

I've got a project where I'm reading in geometry objects from text files to put them in ArcSDE. These geometry objects have an associated EPSG code, and I'm looking for a way to ensure they're in the right projection when I've finished with…
om_henners
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2 answers

Instantiating spatial polygon without using a shapefile in R

So, the usual way we read a shapefile in R is via the maptools package, like this: sfdata <- readShapeSpatial("/path/to/my/shapefile.shp", proj4string=CRS("+proj=longlat")) However, I have a use case whereby I don't have a shapefile.shp but instead…
Calvin Cheng
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3 answers

How can we protect GIS data?

I have found a very interesting paper here related to this topic. I just want to have views/ideas from other professional about how we can protect GIS data using Cryptography or Digital Watermarking? Any suggestions, especially for Administrative…
iRfAn
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2 answers

Safely storing paper/hardcopy maps

What do I need to consider when deciding how to preserve paper maps safely from the ravages of time? I am trying to understand some best practices when it comes to archiving and storing paper maps. Some things one may have to consider... Paper…
SaultDon
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22
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5 answers

Is there a source for historical shapefiles and tiles?

Is there a source for historical shapefiles and tiles? Like the ancient Greece/Rome, medieval Europe and Japan? Ideally with multiple snapshots during different periods in their development, since they've gone through quite a bit of restructuring…
Alex K
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22
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1 answer

What's the status of Postgis 2.0 topology support in QGIS?

Having followed the Postgis developments over the past 6 months I have noticed a bunch of features which seem to be incredibly cool especially in the area of topologies and associating calculations on things like intersects, snapping,... What I am…
NetConstructor.com
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22
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5 answers

Map projection in OpenLayers

I want to overlay some data whose projection is WGS-84 on Google map layer in OpenLayers. But I just can't make them in the right place. I did as follows: map = new OpenLayers.Map('map', { numZoomLevels: 20, projection:…
ChanDon
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22
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3 answers

Dealing with bridges and tunnels when modeling raster least cost paths?

I'm currently using ArcGIS 10 Spatial Analyst's Cost Path tool to model pedestrian routes. I have sidewalks, fences, buildings and a ton of pedestrian scale features, all combined into a cost surface in which sidewalks are low cost, parks are…
julie
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22
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8 answers

Fixing thousands of small overlapping polygons?

I'm using ArcMap 10.3. I have a layer of different land use types. I found out that many polygons overlap each other and as a result the same polygon have two different land use types. Using @radouxju's answer, I built a topology for the land use…
shiny
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22
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4 answers

Seeking software to create professional fly-over/ fly-through animations

I will need to create a high quality fly-over animation which penetrates the surfaces and reveals subsurface geology. The intended use is for demonstrations, presentations and a company website so it cannot include copyrighted data. Available Data:…
Jakub Sisak GeoGraphics
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22
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3 answers

Rasterize a shapefile with Geopandas or fiona - python

I need to rasterize a really simple shapefile a bit like this http://tinyurl.com/odfbanu. Which is just a shapefile containing counties in the US. I have seen this previous answer: GDAL RasterizeLayer does not Burn All Polygons to Raster? but I was…
User18981898198119
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22
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5 answers

How to convert a spatialpolygon to a SpatialPolygonsDataFrame and add a column to the attribute table

coast<-readShapeSpatial("coastline.shp") landc<-readShapeSpatial("landcover.shp") ro<-readShapeSpatial("roads.shp") bc<-gBuffer(ro,width=100) landc$ratings=1 landc$ratings[landc$LANDUSE_ID==4]=0 Above, I take any category that has 4 and in the new…
gsa
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5 answers

Seeking developer-friendly web GIS?

I'm a recent Computer Science graduate who prides himself on his knowledge of software development and problem solving, but has no idea how GIS systems work. (Read: I'm a programmer.) I've been charged with developing (ie. coding) a new webmap from…
Sophie McCarrell
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22
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1 answer

Is it possible to generate a boustrophedon pattern which fill a vector Region with GRASS?

Is it possible to generate a boustrophedon pattern which fill a vector Region with GRASS? I have a vector region in GRASS. And I would like to generate a vector (a polyline) being the bostrophedon pattern which fill this region. In the picture…
Adrien BARRAL
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3 answers

Using R with ArcGIS Desktop?

I've used the integration of R with QGIS, and found it a very uesful tool. Having taken a look at the R toolbox extension for 9 and the extension for 10 it appears they both offer only point clustering to demonstrate the proof of concept. Can other…
om_henners
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