All Questions

8
votes
0answers
344 views

File Geodatabase API .NET Wrapper - Determine if Table/Feature Class Is Locked

I have been using the file gdb api .NET wrapper, and it has suited my needs quite nicely (vs using ArcObjects). One of the things I have yet to figure out if there is a proper way to determine if a ...
8
votes
0answers
609 views

How to define Winkel Tripel in proj 4.8.0?

I have QGIS with proj 4.8.0 installed. I'd like to add Winkel Tripel projection which seems to be defined as +proj=wintri But that definition string does not work. Is this a bug in my proj version, ...
7
votes
0answers
116 views

How to produce high-resolution DEMs from new Sentinel-1 data?

This is a general question relating to the new Sentinel-1 data. I'm interested in the potential for using this data to create high resolution DEMs in GIS (I use QGIS), to investigate archaeological ...
7
votes
0answers
156 views

Geotransformation for polar stereographic?

I'm currently working to import CANGRID climate data (provided as Surfer Grid ascii, ".grd" files) into ArcGIS. The grid is 95 rows by 125 columns in size.Metadata provides lat/lon of origin (lower ...
7
votes
0answers
789 views

GRASS v.Overlay/QGIS Intersect Speed intersecting line and polygon

Im currently trying to convert my scripts from ArcGIS to QGIS but one aspect that is extremely slow (imo) is trying to intersect a polygon with a line feature. I feel as though there must be a better ...
7
votes
0answers
215 views

How does Spatialite handle concurrent access?

I understand that Spatialite is meant to be used by a single user/machine at a time. However if the data is stored on server, there is no guarantee that someone on another machine will not also open ...
6
votes
0answers
133 views

How to compute the smallest network that connects all points using PostGIS?

I have a set of postgis scripts which generates two tables - one of a set of points and the second a set of roads which surround them. All data is in the same projection and both outputs are stored in ...
6
votes
0answers
91 views

Reprojecting elevation dataset for “tilted Earth”

I would like to create maps of a "tilted Earth", such as the following example where Australia is at the North Pole: http://i1048.photobucket.com/albums/s379/laskaris_mods/tilted_earth.jpg I can ...
6
votes
0answers
309 views

Histogram Matching Python

I am trying to do histogram matching using Python to improve the mosaicking process of multiple overlapping rasters. I am basing my code on that found at: ...
6
votes
0answers
142 views

ArcObjects running in Addin slower?

I have created a class library which does some geoprocessing. The addin calls a class that is an async process. I have ensured the thread is STA and the arcobjects are thread safe (ie. not passed from ...
5
votes
0answers
50 views

Mousewheel event being locked by map

I've got a tabbed UI on my web page, the last tab is an arcgis javascript map built with their API. The problem I'm having is that just adding the map and all of the esri / dojo libraries to the page ...
5
votes
0answers
86 views

Why does a z factor of 1 get turned into 0.999998 in my output

Just built a model that uses 3D Analyst - Surface Volume. I am trying to use a z factor of 1. Whenever I run the model my output table shows that a Z factor of 0.999998 was used instead of 1. I ...
5
votes
0answers
82 views

How to add an attribution on a GeoJSON Layer from Leaflet?

I need to use a GeoJSON Layer on my Leaflet map. Here is a sample of my code: function onEachFeature(feature, layer) { if (feature.properties && feature.properties.popupContent) { ...
5
votes
0answers
268 views

Cheapest centimeter accurate satellite positioning (GNSS/GPS)

I am looking for a cheapest possible GNSS/GPS setup with a centimeter precision without much HW hacking. I am not able to produce my PCB or do any soldering (though I would do that if there is no ...
5
votes
0answers
49 views

editor tracking updated in attribute table, but not in sql server database

When I enable editor tracking and make modification on an object, I can find the edit user and edit time, but I cannot find the data updated in the sql server database. Is it because of the ...
5
votes
0answers
34 views

How to extract sublinestring from a linestring with overlapping segments

Problem statement: Given a bus route (defined as a linestring ln.the_geom), and a set of bus stop locations (pt1.the_geom,pt2.the_geom,...ptn.the_geom), divide the bus route into segments between bus ...
5
votes
0answers
96 views

What PostGIS [topology] provided tools may be used for data quality assurance?

I'm learning about techniques to ensure GIS data quality. Googling around, I've found a few papers about theory and best practices (here and here), and a couple of short presentations about the topic ...
5
votes
0answers
398 views

How to create a customizabe table in QGIS Print Composer?

I would like to add a custom table to a map layout created in QGIS. I would like a fair bit of control over the look of the table (borders, background colours of the cells, etc.), and it appears that ...
5
votes
0answers
358 views

PyQGIS CRS on the fly reprojetion

As a first step of a pyqgis plugin I'm trying to import several shape files at once. To get them aligned, using the GUI, I'd enable on the fly reprojections and set the project crs to WGS84. I'd then ...
5
votes
0answers
344 views

Modifying File GDB Feature Class Features Using QGIS

I've installed the File GDB API using the OSGEO4W advanced installation when installing QGIS. I've had a bit of trouble with it initially and have posted a few questions with some helpful Stack ...
5
votes
0answers
190 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 ...
5
votes
0answers
360 views

Grouping analysis of points to divide a polygon into n number of sub-regions

I'm attempting to create n sub-regions from a polygon based on a cluster analysis of a bunch of overlapping raster layers (physical layers, eg: depth, currents, waves). Briefly, I can create a ...
5
votes
0answers
106 views

Is IGraphicTracker leaking memory?

It seems that when geometries are removed from an IGraphicTracker instance, the geometries remain in memory until IAoInitialize.Shutdown() is called. I have tried removing the geometries by calling ...
5
votes
0answers
259 views

Plugin Workspace: when to close an OleDbDataReader?

I'm developing a plugin workspace for ArcGIS. Internally, the plugin uses an OleDBconnection. All of the sample code I see seems to stress the importance of closing and disposing the connection. ...
5
votes
0answers
77 views

Can I verify that attribute indexes are being used in a query from ArcObjects?

We have some software as part of a larger project written using ArcObjects via .NET. This software migrates and merges data from multiple file geodatabases in one schema to a single file geodatabase ...
5
votes
0answers
508 views

Evaluating map projection scale error

This is related to a previous question I posted. I am trying to quantitatively evaluate scale distortion associated with choosing different projection center, center azimuth, and scale factor values ...
5
votes
0answers
887 views

Calculating compass bearing between two GPS coordinates… with a twist

I'm building a virtual tour application that uses Google's streetview code to render the panoramas into a non-distorted view. Each panorama has 1 to n links where the user can select to move on. I ...
5
votes
0answers
598 views

How to get rpy2 for QGIS on OSX?

I am a new QGIS user, have installed QGIS on a Mac running Snow Leopard OSX 10.6.8 following all the instructions. QGIS seems to work well for everything other than when I boot up I get the message ...
5
votes
0answers
286 views

How to store Large Raster Images of Equipotential Surface Generation Using Monte Carlo Simulation?

I have a large (1GB+) raster that I am using as the base for the generation of an equipotential surface. This is to assess the accuracy of DEMs derived from another source. In situ observation is ...
5
votes
0answers
731 views

How to create a routable road network from Ordnance Survey data?

I've been following the "Beginners Guide to pgRouting" in an attempt to create an in-house application that provides drive-time isochrones. I have a server, postgreSQL and PostGIS and pgRouting - no ...
5
votes
0answers
638 views

How to use Route Task in Network analysis tools

I am using esri network analysis tool and I just want to draw the path between two clicked point on the map (by using route task) I use the example code block in the following link ...
4
votes
0answers
25 views

Building a Mosaic Dataset with rasters that are not georeferenced. Whats the workflow?

I have 68 aerial jpegs that I would like to use in a Mosaic Dataset. They have not been georeferenced. My question is in regards to whether I should georeference them and then rectify and save them in ...
4
votes
0answers
18 views

Clusters of Same Size?

I am attempting to use the Grouping Analysis tool in the Spatial Statistics (in ArcGIS 10.2) to group state high schools (points) together based on enrollment and location. Is there a way to make ...
4
votes
0answers
32 views

how to compare geometries (contains, within) in arcpy?

I am trying to use 2 geometry objects to check if a line is within a (rather complex) polygon. The geometry check always fails, even if the line is clearly within the polygon. I use the following ...
4
votes
0answers
67 views

Focal Statistics for Special Neighborhood

I'm looking to calculate focal statistics for each cell of a raster, within a neighborhood of a specified criteria. Background - I have three binary rasters, each representing a single vegetation ...
4
votes
0answers
32 views

ArcObjects .NET - How to close/release FeatureClass, Workspace, Factory

I have a long-running process. I want to prevent resource leaks or rogue database connections. At intervals during the process I want to do this: get an ArcSDE (Oracle) workspace factory open a ...
4
votes
0answers
69 views

ArcGIS model builder - make query layer with query parameters from generated values

What I want to do: I want to join a realationship table (same database, not in sde) to a sde feature class to distplay only needed features. This has to be done multiple times according to every row ...
4
votes
0answers
31 views

Modelbuilder Workspaces: Defaults to a folder, would like it to be a geodatabase

I'm having an issue with modelbuilder workspaces. I have created a simple model to clip a raster, run focal statistics on it, and create contours. I have a workspace variable as an input. If I run the ...
4
votes
0answers
49 views

Alternative to Delete Polygons And Extend Lines of Production Mapping?

Maybe someone knows an alternative for the Delete Polygons And Extend Lines (Production Mapping) tool or a simple way to achieve the same result but without requiring a Production Mapping license?
4
votes
0answers
33 views

Interpolating species data from sample points in a small area

I have sample data from a small site (10 acres) which shows the number of occurrences of a particular species of snail over two sampling periods (fall and spring sampling). I want to try and ...
4
votes
0answers
65 views

demers cartogram

How do you make a demers cartogram from a shapefile/topojson/geojson? I have tried scapetoad and indiemapper and i can not duplicate what you find on the links below. ...
4
votes
0answers
23 views

Null Values in Geographically Weighted Regression Analysis

Some of my explanatory variables have a few null values for certain polygons. Can GWR handle these, or should I remove the whole polygon and all data (dep, ind variables for that particular polygon)? ...
4
votes
0answers
51 views

Display a NetCDF file in 3D

Does anyone know how to display a netCDF in a 3D Scene Map in ArcGIS 10.2? something like the pretty 3d graphics at the UC I've got hundreds of thousands of points/cells with values for a stretch of ...
4
votes
0answers
149 views

Concatenate features in one feature class by the unique ID

Is there a way to concatenate features in ArcGIS by using ArcPy, or field calculator, to produce the following output? I am aware of the concatenate tool that Esri created, however it doesn't keep ...
4
votes
0answers
38 views

How to calculate an Illumination raster for fire ignition danger analysis?

I am doing a fire ignition danger analysis using this equation that I found in Millington (2012) http://www.jmecology.com/wp-content/uploads/2014/03/33-42-MILLINGTON.pdf IR = 4H + 3V + 2I – E Where: ...
4
votes
0answers
72 views

Simplified flood “model” / estimation from elevation data

The goal is to present an estimation of potential flooded area. But still keeping it simple. I know this will not be accurate. The question is: will it be good enough for at gestimate / rough ...
4
votes
0answers
123 views

How to create animated timeline in ArcGIS for Desktop?

I can't find any options in ArcGIS timeslider to create a timeline like presented in this video. The video itself is a guide for creating time animation, but no information is given how to create such ...
4
votes
0answers
50 views

ArcObjects : Out of Server Memory when reconciling a large edit session

One of our users has been periodically experiencing 'Out of Server Memory' errors with ArcSDE 10.0 when trying to reconcile a large edit session. VMware ESX Instance: Windows Server 2008 R2 ...
4
votes
0answers
81 views

How do I parse the file format for attributes in Raster Product Format (RPF) maps and imagery?

I'm trying to implement an open-source NITF reader (using only java, no external libraries such as GDAL or NITRO), and its mostly going OK. However I'm having trouble understanding the RPF extensions, ...
4
votes
0answers
48 views

Classical or robust variogram for incorporation into generalized linear model

I'm modeling counts of organisms over time at eleven locations. I'd like to account for temporal autocorrelation in the counts, assuming it's present. As the data are not equally spaced in time, ...

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