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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0answers
675 views

two results of IDW in ArcMAP are different

i added the following points to ArcMAP using "Add XY Data". x,y,z 7,39,117 27,17,122 27,61,123 46,36,136 52,14,138 55,46,141 56,56,137 65,24,144 65,36,145 Changed raster output size in "options" ...
4
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1answer
197 views

How to determine correlation between two databases?

I need to perform some tests and verifications on databases and/or datasets. I need for example to analyze two databases and then determine if there is enough correlation between both. My main issue ...
1
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0answers
162 views

Plotting time-series data in ArcGIS

I'm attempting to produce interpolated plots of water quality time-series data from ArcSDE. This is the data format: OID WELL_ID WELL_NAME SAMPLE_ID SAMPLE_DAT PARAM RESULT ...
9
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3answers
1k views

Calculating mean slope: Harmonic or Arithmetic Mean?

I have to calculate the average upslope percent slope for a large dataset, the basic method is detailed here. However, I've begun to wonder if harmonic mean might be more appropriate than the ...
7
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1answer
488 views

Comparison of three contour lines

I am looking for a way to spatially quantify the difference between three contour line shapefiles. More specifically, I have two elevation rasters which I intend to create contour lines from, but ...
2
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1answer
560 views

Why won't Tabulate Intersection work?

I can't seem to find much in forums about this - I'm trying to use Tabulate Intersection with two shapefiles. When run in a model, I get a generic error (Error 999999:Error executing function). ...
2
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1answer
140 views

Raster export for regressions analysis

I have the following issue: I am trying to do a regression analysis between the (z) values of two rasters. What I would ideally like to have is the raster output not as grid but rather a list of ...
3
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1answer
256 views

Calculating Mean Upslope slope, curvature, etc

I'm trying to generate rasters whose values summarize the mean value of a given parameter (slope, curvature, etc.) of the upslope terrain. I feel like this should be doable using only a flow ...
8
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1answer
266 views

(How) do the modifiable areal unit problem and modifiable temporal unit problem interact?

I am reconstructing historical time series of land use and other related data from a variety of sources with different spatial and temporal resolutions and would be interested in what possible ...
9
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1answer
456 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
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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
113 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
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1answer
252 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
306 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
602 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
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1answer
681 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
484 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
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0answers
26 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
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5answers
574 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
318 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
483 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
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4answers
4k 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
150 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
701 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
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1answer
348 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
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1answer
208 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
715 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
479 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
260 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
14k 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
527 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
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0answers
136 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
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1answer
373 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
712 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
232 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
497 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
857 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
698 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
783 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
261 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
287 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
624 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
1k 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
314 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
745 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
325 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
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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 ...