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19 views

Geoserver Optimization: 64 bit vs 32 bit + JAI?

Since as per my knowledge jai does not support 64 bit, what would be more efficient: a Oracle Corporation: 1.7.0_79 (Java HotSpot(TM) 64-Bit Server VM) Vs Oracle Corporation: 1.7.0_79 (Java ...
1
vote
2answers
41 views

Finding Network Data for Route Optimisation in Saudi Arabia using ArcGIS?

I have to do a route optimisation through ArcGIS vrp solver for 1200 pizza drop points/daily, for a city based in Saudia Arabia. Where can i get the road network dataset?
1
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0answers
33 views

Optimize Postgis contour lines DB

I'd like to try to optimize a world-wide 10m contour lines (isohypses) Postgis database(from SRTM). The complete DB takes 504GB on disk, contour lines are already in epsg:3857, and simplified with ...
1
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0answers
35 views

Location-Allocation “Like” Problem using Polygon data

I am a political scientist interested in malapportionment. I have a population data which has the municipality-level population and polygon format, so it can show how many people are living in the ...
6
votes
1answer
104 views

How to group 10k points into closest pairs?

I was first faced with a problem of grouping 1000 pairs into unique pairs to minimise the total distance - since this was a small number I solved it using linear optimisation: Part 1 - Basic/Naive ...
0
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0answers
127 views

Google Maps iOS Optimized Route returns zero_results

I have an app that lets the user generate a route using a origin/destination point and waypoints in between. If I submit the url without optimized:true in it I get a polyline back that goes to each ...
3
votes
1answer
45 views

using a linear solver to get a “centre of gravity” of a set of points

As a programmer, if I have a linear solver available. How can I formulate the following problem as a set of constrains / decisions / goals for the linear solver? I have a matrix of say 10*10, so 100 ...
3
votes
2answers
93 views

Grass GIS: Number of CPU cores to use

E.g. in SAGA GIS it is possible to set with one click the number of CPU cores to use during processing. Is this also possible in Grass GIS?
1
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0answers
31 views

What is the quickest way to find in which plots a set of points lie?

I know this sounds easy and lazy to ask, but I'm new to (spatial)database, and I have the feeling my solution is sub-optimal. But for my situation it's important to have good performance. What do I ...
1
vote
1answer
83 views

Suggestions of route optimization algorithms to implement in QGIS

I need to compute routes on a QGIS project with time and distance associated. Is there any route optimization algorithm to compute routes given the points that one wants to connect?
2
votes
1answer
32 views

Optimized walk lists for door-to-door traversal of a region

Given a region in a city, I'd like to make a list of all the street addresses it contains in an order which is reasonably efficient for a person to traverse on foot. Ideally, I'd like the solution to ...
1
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0answers
77 views

TileStache PNG Optimization

A Tilestache config file has a "png options" object that passes its config straight through to the Python Imaging Library (PIL). Setting optimize: true does some kind of optimization as the file is ...
3
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0answers
111 views

Steiner tree problem: Optimal routes for Fibre planning on road network

I am trying to solve a large optimization problem where I have a set of nodes on a road network that need to be connected using fibre using the shortest possible amount of fibre. The problem is a ...
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0answers
152 views

Location allocation optimization using R?

I need to allocated zip codes to offices. Each zip code has certain demand from 0 to 120 clients and each office has certain capacity from 500 to 2500. How do I do this so that: All the zip codes ...
3
votes
0answers
189 views

Memory issue inserting a large dataset in GDB with ArcObjects

I am using the ArcObjects API for Java to load a very large dataset in a File Geodatabase in one feature class. The whole dataset I have to load is composed of 200 datasets of 30k polygons, and I ...
1
vote
0answers
67 views

Managing Very Large Vector File Geodatabases

I am currently looking for ways to more effectively work with an extremely large 10,000,000 (+) vector features contained in a file geodatabase. Its just very cumbersome to work with in ArcGIS (v ...
1
vote
1answer
195 views

How to find the best location to put a facility within network so that all points are near a facility?

Suppose I have many points distributed in a network. I want to place three facilities in the best way so that all points are near a facility. How can I do it? Any solution and software should be fine ...
2
votes
2answers
740 views

Maximizing Code Performance for Shapely

I've written this code in order to calculate the percent cover of grassland within a national park, within 20km^2 of points of recorded occurrences for a species. It is designed to only consider the ...
6
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0answers
148 views

Postgis database query optimisation

I have a set of rasters in DTED format which I load into postgis database using raster2pgsql command line tool. Each of rasters is simply stored in a row and described by rid and a value of raster ...
3
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1answer
1k views

Coordinate conversion (EPSG:3857 to EPSG:4326) using OpenGIS/JTS too slow

I am using the Java based libraries of OpenGIS and JTS to convert coordinates from EPSG:3857 to EPSG:4326 to proceed to compute the distance using the Haversine formula. The distance features in a ...
6
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4answers
1k views

How to optimise and speed up Python code? [closed]

Again my lines of surface runoff... I made a script, solving the issue when lines cross other lines. Something like generalization. Like on the picture below. The problem is that I have to solve 30 ...
3
votes
1answer
253 views

Maximize clusters of points from coordinate data

So I am definitely new to the GIS world, so bear with me if I don't know the best way to articulate my problem. That said, I am ready to learn, I would definitely welcome any direction that you all ...
0
votes
1answer
69 views

Improving speed on pgRouting on table update with many rows: faster to loop on each row than a table update call?

I am updating thousands of rows in a survey table finding shortest path from each place a survey respondent visits. My code below is the query I use to update the blank route column. The function ...
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0answers
24 views

How to build an optimization model? [duplicate]

I want to make a model using QGIS. Is it possible? Then how can I develop a model. can anyone help me?
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0answers
88 views

I could use some help with a bit of code optimization

See edit below. I posted here a couple weeks ago looking for some advice on the best way to iterate through data. You can find that post here. I have since done some tweaking to the code, and ...
0
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2answers
113 views

How can I optimize this point-linking query?

I have the following query, and am wondering how it could be optimised to run faster: WITH gps_nodes_1 AS ( SELECT "NODE_ID", "geog" FROM gps_nodes WHERE ST_Distance("geog",ST_GeogFromText('POINT( ...
1
vote
1answer
103 views

Wind turbine placement optimization and loss on surrounding house value

I am doing a geostatistical placement optimization study on where would be the optimal placement of a wind turbine in a Danish region. One of the variables taken into account is the cost on the value ...
5
votes
1answer
148 views

Optimize the locations of 2 additional restrooms on a trail (ArcGIS 10.2)

In the image below, the line is a trail and the point is an existing restroom. I would like to find the rough locations of 2 additional restrooms that minimize the maximum distance along trail from ...
3
votes
0answers
133 views

District heating expansion design with ArcGIS [closed]

I am quite new at GIS but I have some experience of the basic concepts involved in a workflow of them. What I currently want to do is to calculate the cost of expanding an existing district heating ...
2
votes
2answers
1k views

How to draw one rectangle in ArcObjects?

Is there button in ArcObjects "draw rectangle" such as in openlayers? Update Well, I use this code for drawing: ESRI.ArcGIS.Display.IScreenDisplay screenDisplay = Map1.ActiveView.ScreenDisplay; ...
4
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3answers
443 views

How does Jenks optimisation method assist in ESRI mapping?

Why would someone use the Jenks optimisation method in ESRI mapping? What would be easily located or discovered with this analysis?
4
votes
1answer
206 views

Which spatial bundling or grouping algorithm optimally groups elements by attribute?

As I delve deeper into GIS, I find myself trying to improve efficiencies of certain procedures and processes. The one process I'm working on now is spatially scheduling construction projects. For ...
4
votes
1answer
617 views

meeting point minimizing travel distance for participants?

The problem is to find the point minimizing the travel distance for around 100 persons in different regions who want to meet in the same place. Travel is by car not by plane. Assuming that I get ...
3
votes
1answer
594 views

Find nearest neighbours faster in PostGIS

I currently have a query that calculates the number of useful amenities within a certain radius of each town, using OSM data: create table places as select town.name, place, town.way, ( select ...
3
votes
2answers
893 views

PostGIS - ST_Collect but only include POLYGONs not POINTs?

In PostGSI, is there anyway to turn a GEOMETRYCOLLECTION into a MULTIPOLYGON by dropping all non-POLYGONs/non-MULTIPOLYGONs? I'm doing a query that cuts a bunch of geometries (using ST_Intersection) ...
2
votes
0answers
240 views

Covering a Polygon with Minimum number of circles with fixed locations

In QGIS, I have a vector polygon of a fixed size and shape. I also have a set of circles of a fixed radius and fixed location, which cover part of the polygon. What I would like to do is remove as ...
11
votes
2answers
4k views

How can I more efficiently select related records?

Below is the code I'm using to replicate the "related tables" button in ArcMap. In ArcMap that button selects features in one feature class or table based on the selection of features in another ...
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2answers
626 views

How do I reduce the number of drawn polygons on an Android Map?

We're using spatialite-android and Nutiteq to render Archaeological datasets. One of our sample data sets has 7000 polygons that turn into 400,000 objects in our renderer. Is there a common GIS ...
8
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2answers
242 views

Algorithms for optimally locating points

I am trying to compare locations of where several thousand facilities have been actually built to where they would be optimally located to minimize travel times of the population (represented by ...
12
votes
2answers
2k views

How to equalise colour, brightness and contrast across several scanned paper maps

I am a vectors guy mostly, but for a current project I need to work with a bunch of old scanned paper maps (ww2 bomb damage maps for London, if your interested!) We scanned and georeferenced the ...
26
votes
6answers
12k views

Ways to Speed Up Python Scripts Running As ArcGIS Tools [closed]

This is a pretty general question. I just wondering what tips and tricks GIS programmers have used to speed up arcpy scripts that you import into the toolbox and run. I work most everyday writing ...
3
votes
0answers
344 views

Shortest distance from pgrouting with cost not being length: optimal solution

I'm using pgrouting shortest_path_astar with a complicated cost function. It gives back the edges, vertices and costs. I would like to get the total distance of this shortest path (i.e., the sum of ...
5
votes
3answers
3k views

Slow IE8 responsiveness with OpenLayers and many features

Background Adding about 700 sites to an OpenLayers Map. Firefox 11 and Google Chrome display the sites just fine. IE8, which is the organization's standard and will not be upgraded for the ...
1
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0answers
25 views

How to make some constraint to be evaluated first in mysql?

SELECT BusinessID FROM tableauxiliary WHERE MBRContains( GeomFromText ( 'MULTIPOINT(-6.1928749092968 106.7651250907,-6.1771250907032 106.7808749093)' ), ...
11
votes
1answer
608 views

Are there any intelligent travelling salesmen?

Jokes aside, I have had a routing problem that is almost a travelling salesman problem (TSP): the starting point is defined the end point coincides with the starting point each node has to be ...
15
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1answer
176 views

Alternative indexing methods for point set operations

It is common to use a bounding box spatial index to improve performance when working with a large number of features. Where operations are performed against individual geometries with a large number ...
2
votes
3answers
260 views

Looking for TSP with Target different from Source

I know the TSP (traveling sales person) in osm2po is beta but it works quite well. Is there a way to designate a final target location that is different from the initial source location. In other ...
2
votes
1answer
770 views

How to speed up this simple MySQL points in the box query

MySQL doesn't have nearest neighbor search so. So I try to come up with a "distance" that's reasonable so the number of returned query is around 20-200. That way innodb doesn't have to compute ...
6
votes
1answer
855 views

PostGIS query vs QGIS filter

I have a PostGIS dataset with around 3 million shapes. I only need to view about 1,500 of these shapes at any given time, but the shapes I need to see depends on which feature is selected in a ...
7
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3answers
3k views

how to find 20 closest points efficiently

Say I want to find 20 closest business near me. My table structure is like this: BusinessID varchar(250) utf8_unicode_ci No None Browse distinct values Change Drop ...