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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9
votes
1answer
412 views

Compare spatial cluster/agglomeration patterns for polygon data

I have agricultural data in form of polygons which I would like to test for spatial clusterings/spatial agglomerations. All in all I have about 40 variables which I can aggregate and standardize in ...
5
votes
1answer
2k views

Creating a subset of points shapefile with minimum distance between points in ArcGIS 10 [duplicate]

I have a sample of ~700 animal locations that I will be using for habitat selection analysis. I am trying to figure out a way to subsample my locations in a way that will maximize my sample size for ...
6
votes
1answer
111 views

What does shading indicate in home range plot?

I've simulated a home range in R using the clusthr function from the adehabitatHR package. The home range is made from 50 x,y coordinates. The output is attached. I'm trying to get clear on what ...
6
votes
1answer
242 views

how to aggregate the rates, represented by points, within X radius

the point represents rates like 10%, etc. (this was also pretty clear from 2 years ago) -- been trying to do this for 2 yrs... the points dont represent numbers of events since they are rates ...
5
votes
2answers
1k views

How to implement bivariate Ripley's K function in ArcGIS 10?

The attached image shows a forest gap with red pine represented as circles and white pine represented as crosses. I am interested in determining if there is a positive or negative association between ...
-3
votes
1answer
273 views

How to calculate cumulative mean in Arcgis

I'd like to get cumulative mean value from a multiband image (4 bands). How can I do it in Arcgis, ERDAS and ENVI? Thanks in advance
5
votes
3answers
548 views

How to test spatial correlation between two point layers

I have two point layers, which visually have spatial correlation. I'd like to test it but wonder if there is such a method or index?
3
votes
2answers
1k views

What is an appropriate statistic to measure spatial autocorrelation of points with binary values?

I am trying to determine the level of spatial autocorrelation in a point dataset. The attribute I'm interested in is binary (presence/absence of a species), for which Moran's I is not appropriate. ...
4
votes
1answer
623 views

Self organizing maps and spatially Constrained Clustering in R

There are a few algorithms to perform spatial clustering in R but most of them focus on point pattern analysis (for example here). I would like to perform spatial constrained clustering for polygon ...
4
votes
1answer
427 views

How to Reduce Decimal Precision of Image Value in ArcGIS?

I'd like to ask about the value on following image. This is an interpolated precipitation layer using IDW method in Arcgis. On this layer, the values is like this: This is a raster image. After ...
2
votes
0answers
25 views

How to interprete ArcGIS kernel density units when a population parameter is specified? [duplicate]

Possible Duplicate: How to interpret GRASS v.kernel results? The attached image shows trees in a study area based on their actual height in the field. The trees are overlaying a raster ...
11
votes
5answers
492 views

Learning Spatial Statistics

I have a significant background in statistics, and I'd like to learn more about spatial statistics (and statistics associated with geospatial data). Are there any especially good resources for ...
2
votes
1answer
292 views

Accounting for Spatial Autocorrelation in ZINB Model?

I'm doing an analysis on disease in Chile. I'm using the rate as the Dependent Variable and both remote sensing and housing-type data as the Independent Variables. I have several questions regarding ...
5
votes
2answers
420 views

Spatial Analysis with Factors/Classifications

When doing analysis on spatial data with associated information that is numeric, it is possible to use techniques such as Kriging or Interpolation or Cluster Analysis to find out interesting ...
1
vote
4answers
3k 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 ...
1
vote
1answer
142 views

How can I multiply each band of multiband image by separate scalars?

I have an image with 5 bands. I need to multiply each band of this image by different scalars one time (I'm lazy to do it one by one) and then get multiband image as a output. For example ...
5
votes
2answers
666 views

Spatio-temporal block kriging with R package gstat?

In the documentation of sp I saw that the coords argument of the SpatialPolygons function only accepts 2 columns. Is it not possible to create 3-dimensional polygons? I am doing spatio-temporal ...
10
votes
1answer
326 views

How to create an error map to support an average kernel density map?

I've created an average kernel density map by running KDEs on points stacked within the same spatial extent. For example, say we have three point shapefiles representing seedlings in three different ...
2
votes
1answer
200 views

Obtain normalized raster average per polygon?

I have a raster that contains percentages of total forest killed plus a polygon layer that defines different zones. My goal is to find a good statistical representative that describes the forest ...
4
votes
1answer
634 views

How to write values from arcpy statistical output to table?

The attached script is my stalled attempt to perform the following workflow: Create a table and create fields Loop through a folder of point shapefiles and perform average nearest neighbor analysis ...
6
votes
1answer
439 views

Calculating “relative slope” per Mora-Vahrson method in ArcGIS

I'm a longtime lurker who finally decided to register on the forum (in no way driven by my need to have a certain question answered, of course...). I was contacted by a colleague asking for help ...
3
votes
0answers
248 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
4answers
12k 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?
14
votes
3answers
494 views

How to determine if trees within forest gaps are clustered?

The attached dataset shows approximately 6000 saplings in approximately 50 variable sized forest gaps. I am interested in learning how these saplings are growing within their respective gaps (i.e. ...
9
votes
2answers
1k views

How to get the second nearest neighbor between two point patterns in R?

Is there a way to get the distances for the second nearest neighbor between two point patterns in R? The spatstat package has a function called nncross but it only applies to the nearest neighbors ...
2
votes
0answers
128 views

How are geographic coordinates stored for multivariate statistical analysis? [closed]

In terms of Principal Components Analysis or Multiple Discriminant Analysis, I have used dummy variables to represent a group of like-features that are located in the same geographic region. For ...
11
votes
1answer
338 views

How to associate polygons with the nearest point on a point layer? (Or … how do I assign a postal area to a salesman?)

I have a polygon layer of postal code areas and I want to use them to create sales territories based on where our sales people are based. So I assume that I need to work out for each of the polygons ...
4
votes
2answers
665 views

Spatial query of raster data

I have population distribution data as a raster layer and exposure contours as vector (polygon) layers. What I'd like to do is use the vector layer to estimate the population indicated from the raster ...
1
vote
1answer
228 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) ...
8
votes
1answer
470 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 ...
2
votes
1answer
786 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 ...
4
votes
2answers
665 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 ...
1
vote
1answer
698 views

Modelling Sea level rise scenarios for a Coastal county in ArcGIS

I am a graduate student @ Clemson University and am working on a GIS based project which is to model different sea level rise scenarios and estimate its impacts on a coastal county and to suggest ...
4
votes
1answer
244 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 ...
5
votes
1answer
274 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 ...
14
votes
3answers
604 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 ...
2
votes
1answer
958 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: ...
6
votes
2answers
291 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 ...
4
votes
2answers
724 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
4
votes
1answer
300 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 ...
16
votes
1answer
1k 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 ...
5
votes
1answer
210 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 ...
4
votes
1answer
415 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 ...
5
votes
3answers
1k 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 ...
9
votes
1answer
274 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
156 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 ...
6
votes
2answers
388 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
96 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 ...
6
votes
2answers
808 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
602 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…). ...