The field of study concerning statistical methods that use space and spatial relationships (such as distance, area, volume, length, height, orientation, centrality and/or other spatial characteristics of data) directly in their mathematical computations.

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3
votes
0answers
350 views

How do I access layer attributes from within QGIS' manageR plugin?

This is probably a fairly basic question, but searches for manageR come up with a lot of noise, and there's no manageR tag. What I'd like to do is load the attributes from a particular field of a ...
7
votes
1answer
261 views

Which spatial weighting function does ArcGIS' GWR use?

I am running Geographically Weighted Regression and originally was using ArcGIS to carry out the analysis until I read/heard mixed reviews about it. I have now tried a different programme to run it ...
28
votes
2answers
4k views

How can I conduct Geographically Weighted Principal Component Analysis using ArcGIS, Python and SPSS/R?

I am after a description/methodology for conducting a Geographically Weighted Principal Components Analysis (GWPCA). I am happy using Python for any portion of this and I imagine SPSS or R being used ...
12
votes
1answer
862 views

Are Zonal Statistics possible in PostGIS2?

Now with postgis2 which supports rasters by default is it possible to do a zonal statistics analysis? I've google it but I haven't found anything solid? Is there a tutorial outthere to get me ...
1
vote
1answer
494 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
1answer
286 views

How to fit a polygon to a “best buffer” about a reference geometry in it?

If I have a polygonal geometry gbase, like a street (a rectangular strip), and a reference geometry gref, like a central line of gbase. The question is what is the function (here named BestBuffer) ...
5
votes
2answers
930 views

How to find the watershed for each outlet point and sum values within it?

I have the following files to work with: Stream network of a basin; Outlet points for each segment* of the network and Points which represent water withdrawals along of the stream, which are not ...
4
votes
1answer
573 views

Statistical analyses for survey against raster?

I am somewhat of a newbie to geostatistical analyses, but pretty familiar with GIS and remote sensing packages. I was wondering if anyone had suggestions on appropriate geostatistical analyses for a ...
2
votes
1answer
2k views

Defining datum for Lambert Azimuthal Equal Area and converting to geographic coordinates

I posted this question to a specialised mailing list for spatial data analysis using R here but didn't recieve a response. I am working with shapefiles and rasters in R, and I am unsure if I am ...
5
votes
1answer
1k views

Trouble with Hot Spot Analysis (Getis-Ord Gi*) tool in ArcGIS

I am trying to locate areas with a high rate of accidents involving bicyclists or pedestrians per car accident of any kind. I have a point file of accidents and a point file of all those with ...
8
votes
2answers
3k views

How to Find the Average Raster Value of an area defined by a shapefile using R?

I have a set of raster images which represent a specific month over the years, and I want to make a timeline of the average values of an area using a shapefile. How do I extract the values from the ...
5
votes
1answer
382 views

Spatial regression

I have a question regarding performing spatial regression on data which residuals are spatially correlated. If the residuals are spatially autocorrelated due to the presence of trend, how should I ...
8
votes
1answer
962 views

Modifying Bivariate Moran's I /LISA to include self?

I am using GeoDa's Bivariate Moran's I function to examine patterns of collocation between two variables at the county level (call them A and B for now). I know that, having run the analysis I can ...
14
votes
3answers
787 views

Ecological geospatial conundrum

I am looking for a different, more elegant solution to a spatial statistics problem. Raw data consists of an x-y coordinate for each individual tree (i.e. converted to a point .shp file). Although ...
9
votes
4answers
33k views

How to convert zip codes to latitude and longitude?

I have a data set that includes a list of zip codes. Is there a way in R to convert these zip codes to latitude and longitude coordinates?
6
votes
2answers
494 views

How do I process xy data to be compatible with census block data (so I can include them in my GWR model)? (ArcGIS 10)

I'm pretty new to GIS, so apologies if my problem is rather simplistic I'm planning to do regression analysis (GWR) on several datasets, where all but one is based on census areas (UK OS lower level ...
11
votes
2answers
2k views

Regression Model and Spatial Autocorrelation

I have used OLS and GWR for validating the dependencies between two distinct database. The Residual Square for GWR is 0.82 and thereby making it the right regression model to be used for determining ...
2
votes
1answer
1k views

Why are Low Values showing as hot spots?

Im running hotspot analysis on point data, attempting to examine pollution emissions. I ran spatial autocorrelation first in order to determine the default distance threshold to use in the fixed ...
2
votes
1answer
2k views

Outputting results message from spatial statistics tool to text file using Python?

I'm using the following tool in ArcGIS 10 - Calculate Distance Band from Neighbor Count (Spatial Statistics). I'm using a python script to execute this tool several times on different shapefiles: ...
15
votes
6answers
4k views

Spatial statistics software for GIS?

I am searching for spatial statistics software which has many powerful features and supports a GIS interface. Can anyone give me some advice?
7
votes
1answer
400 views

How to use ESRI's spatial statistics tools on average values?

I'm wondering if anyone can tell me whether using the spatial statistics tools such as Getis Ord Gi* "hot spot" analysis in ArcView is advisable when your input data is an averaged value, e.g. the ...
4
votes
1answer
487 views

Finding intersection density for weighted lines connecting points across the continental USA

I'm working on an one-time problem that I'm hoping to solve with a computer program using free GIS libraries (preferably for VB.Net, C#, or Python... Java or C/C++ could work too). Alternatively, I ...
5
votes
1answer
253 views

Spatial graphing, distribution of polygon area over latitudes

Given a polygon in a PostGIS database, what is the best way to create a graph of its distribution over a range of latitudes? I'm picturing a graph of a curve, where the proportion of the total area ...
18
votes
1answer
2k views

Robust alternatives to Moran's I

Moran’s I, a measure of spatial autocorrelation, is not a particularly robust statistic (it can be sensitive to skewed distributions of the spatial data attributes). What are some more robust ...
4
votes
1answer
472 views

Regression with Nominal and Categorical Data

I am doing a project looking at the prevalence of a weeds in an area. As an example, I have the following layers: Weeds Layer (polygons) {categorical data} Each polygon represents a point or polygon ...
4
votes
1answer
459 views

Analysing Information By Vector Grid

I have two vector line datasets and wish to compare the line lengths. While I have already compared the sum of the lengths, I'd like to conduct further analysis down to 250m, possibly lower. I'm ...
9
votes
7answers
3k views

how to overlay shapefile and raster?

I have a shapefile with polygons. And I have a global raster file. I want to overlay the shapefile's polygons onto the raster grid and calculate the mean raster value for each polygon. How can I do ...
5
votes
3answers
2k views

Select maximum number of points more than x meters apart

I have a dataset of ~15,000 points that are locations along ROV survey tracks where measurements were taken. These points can be less than 5 meters apart and the survey tracks often cross or can be ...
7
votes
1answer
378 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 ...
9
votes
1answer
319 views

How to find the most spread out locations?

Probably a very simple question. I have a list of about a thousand potential geographical locations (lat lon), and of those I need to select the 200 locations that are "most spread out". I think that ...
1
vote
0answers
171 views

ESRI Silverlight Cartography - Looking at whats not there

I have line data that has been symbolozied in ways that I don't have time to understand and would like to make a map that tells me =). My general question is how to display the lack of data results ...
7
votes
2answers
657 views

Confidence interval from raster data

I have raster data that represents a probability distribution, i.e. each cell has a probability value (in my case the probability that an animal may be found in the cell), and all the cells add up to ...
4
votes
0answers
103 views

Which spatial statistics tools to use in examining autocorrelation in two layers? [duplicate]

Possible Duplicate: How to compare two spatial point patterns? I am working on a project and have found myself a bit lost as to which types of Spatial Statistics tools I should use to get ...
21
votes
6answers
14k views

How to cluster spatial data in R?

I am very new to R. I have bunch of data points with latitude and longitude. I want to use R to cluster them based on their distance. I have already taken a look at this page and tried clustTool ...
6
votes
2answers
1k views

What are best practices to compare densities and locations between two sets of points?

I have two sets of point shapefiles. They represent two different customer groups for a retail store. Shapefile A represents online customers, Shapefile B represents in-store customers. What I ...
4
votes
1answer
982 views

Simulation envelopes and significance levels

Many spatial analysis packages provide Monte Carlo techniques to simulate upper and lower “envelopes” for a summary statistic as a function of distance (e.g. K-function, nearest neighbor, etc…). ...
3
votes
1answer
399 views

Splitting raster pixels by a polygon's edge?

I have a a polygon shapefile of different regions, and a raster grid of precip data. I want to take the polygon and add up all the raster precip data in each zone. I could use zonal statistics to do ...
2
votes
0answers
116 views

Training courses in geostatistics and spatial modelling [duplicate]

Possible Duplicate: What are sources for current geo-statistical analysis classes/events: open or proprietary Does anyone know of or have been on any training courses that specifically ...
2
votes
2answers
408 views

Choosing an aggregation strategy that will be spatially represented on a google map

I'm under an NDA so I cannot really get into specifics of what I am doing. But, suffice to say, I am taking a large amount of spatially-acquired data and drawing this data onto a Google Map surface ...
10
votes
2answers
3k views

Is there a Free Aggregate Points tool out there for ArcGIS 10?

I need to do some Getis-Ord analysis but first I need to aggregate my points. I know of XToolsPro, but the aggregate points function is locked and you must purchase a license to use it. I am ...
6
votes
1answer
529 views

Normalizing and adding kernel density rasters

I have 4 years of road kill data for one road, though each year has a different sample time frame (i.e. May-June vs. April-October) and therefore each year has a different number of surveys and totals ...
8
votes
3answers
1k views

How to cluster points based on a kernel density?

I have a large dataset with 36k points representing commercial land uses, each with a field containing the square footage. I have run a kernel density analysis on this dataset, producing a raster ...
1
vote
3answers
2k views

How to count pixels of a raster in polygons using QGIS?

I need to compute some statistics of the pixels of a given raster that are coincident to the polygons of a vector file. Is there a simple and effective way to do this in Quantum GIS or similar?
6
votes
2answers
6k views

Performing regression analysis between two variables using ArcGIS Desktop?

I have a temperature image (interpolated from climatic point data) and NDVI data at the monthly interval. I need to do correlation analysis between temp and NDVI. Is it impossible to do this using ...
6
votes
1answer
1k views

QGIS Data Management: How to calculate Standard Deviation?

does anyone know of a way to find the standard deviation of an attribute lying within any given polygon? The plugin dialog "Join Attributes by Location" gives only the options Mean, Min, Max, and Sum. ...
7
votes
5answers
626 views

How to calculate purchasing power on postcode level?

Does anyone know of an algorithm to calculate purchasing power on a postcode level? What source data is needed? Purchasing power on admin. level, population?
8
votes
4answers
2k views

In ArcGIS Is there a tool that will select a percentage (75%) of a whole group of points based on the distance from one separate point?

This is ArcGIS specific. I have 2 point shapefiles A and B, the first one (A) is a single point that contains a lat long, the second (B) is a multitude of points (over 12k) that each contain their ...
1
vote
4answers
7k 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 ...
4
votes
2answers
1k views

Gaussian Plume Model

I'm looking for code to implement a gaussian plume model in 3D. Any suggestions on where to start? Are there any python scripts out there? Thanks
8
votes
2answers
3k views

Spatial statistics tools : clustering analysis on raster data

I've an apparently simple problem, but i can't find a clear methodology to use. I'm tasked to delimit "urban areas" by vector convex polygons, using the Gridded Population of the World dataset from ...