# Tagged Questions

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.

18 views

### Doing spatial correlation between two layers on ArcGIS?

I have two datasets and I'm trying to determine the extent of their spatial relationship. I suspect they are closely related but I would like to produce a map output to illustrate this relationship. ...
164 views

### What algorithm does QGIS use to calculate Nearest Neighbor Index?

I'm carrying out nearest neighbor analysis on a set of geological features in QGIS, trying to find out whether they're clustered or not. I've calculated the nearest neighbor distances using the ...
15k views

### Tutorials to handle spatial data in R?

Does anyone know some good tutorials to handle spatial data in R? I know that there are some packages like rgdal and maptools but I haven't actually found usefull tutorials to get in touch with the ...
49 views

### Finding patterns using ArcMap?

I'm new using ArcMap and I have a GDB of schools (and its enrollment data) at block level. What I need to do is to find the places with the most concentration of enrollment in a radius of 5km. Since ...
25 views

### How to perform statistical test for two sets of points?

(I have asked this question originally on Cross Validated; however, no good answer and someone suggested me to ask the question here). We know that we can perform statistical test (e.g., t-test) for ...
42 views

### Looking for spatial analyst tool between raster and vector layers in QGIS

I'm aiming to do a similarity analysis between a raster layer and a vector layer. The raster layer is a 5-class ice map and the vector layer (points) contains ice jam events data. The goal here is to ...
11 views

### Aggregating Individual District Assignments to Census Block

Working on a solution that may work but figured I'd ask the community to see if there's a smarter way to get this task done. I have a voter registration file with district assignments for each voter. ...
390 views

### How to calculate the average distance among set of points as measure of closeness

I have three series (or tables) of points in PostGIS which I want to compare. I would like to know how "close" each series is when compared to the other two. In other words I would need some measure ...
79 views

### Error while comparing two raster layer in R

I have got a geographic point distribution with N prehistoric settlements with a size of x and want to compare the distribution with an economic simulation, which produces M settlements (Usally N > ...
15 views

### How to calculate spatial GINI coefficient for land use

I am interested in calculating an index of agricultural land inequality for Brazil. I'm thinking that a GINI coefficient would be a good approach given traditional uses of GINI. I have a data set for ...
257 views

### R package spatstat: How to use point process model covariate as factor when pixel image values are numeric

I am trying to model a point process with an image covariate using the ppm() function in the spatstat package in R. I convert my raster to an im object for use with spatstat, and I run into a problem ...
211 views

### Testing correlation between two polygon features

I am working on a project looking at county boundaries for the state of California. I have 2 polygon datasets with this same geographic boundary, and these datasets, when mapped individually, visually ...
360 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 ...
21 views

### Why are spatial lagged exogeneous variables rarely used?

In the publication "Regional Productivity and Income Convergence in the Unified Germany 1992-2000" (link) it is claimed without detailed explanation: "Usually, in spatial econometric models only ...
15 views

### What are the practical differences between Moran's I and Geary's C

What are the practical differences between Moran's I and Geary's C for gridded datasets (e.g. temperature) on a continental scale such as USA? Which is more applicable?
104 views

### Spatial Regression Using Panel Data

I am analyzing a spatial panel dataset using the XSMLE package in Stata. My units are a subset of US states (11) and my panel is strongly balanced. The package returns estimations for Main, Spatial, ...
62 views

### Queen vs Rook neighborhood

Queen and rook neighborhoods are two common ways to calculate statistics for a focal cell. They are also known an Moore and (von) Neumann neighborhoods. I think a "bishop version", i.e. from lower ...
51 views

### Finding Median, Max and Min values from Raster Layers in QGIS

I currently have 10 years worth of January raster datasets (working on just one month at the moment) of cloud fraction cover from MODIS, and am trying to create new 3 separate rasters which will give ...
16 views

### arcgis extensions for GWPCA [duplicate]

Dose anyone knows if there is any toolbox or extension for calculate GWPCA (geographic weighted principal component analysis) in arcgis ? I know there is package for that in R but i dont know anything ...
406 views

### PostGIS: ST_Equals false when ST_Intersection=100% of geometry?

I have 2 datasets consisting of cadastral parcel data - roughly 125,000 rows each. The geometry column is WKB polygons representing parcel boundaries; all data are geometrically valid (the polygons ...
560 views

### Calculating 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 ...
22 views

### Number of events within each elevation class

I'm trying to model how elevation affects fire events for an AOI, I have run my cluster analysis for the fire events and right now I'm trying to calculate how many fire events fall within each ...
25 views

### Calculating Categorical Raster Areas per Polygon

I've got forest fragmentation data from which I've extracted pixels that correspond to forest edges and patches. I've also got a shapefile of counties in a US state. I'm trying to get the area of ...
4k views

### How to implement Spatial Autocorrelation using QGIS or PostgreSQL (or any free application)?

I am a total newbie on the GIS scene so I hope this is not a stupid question. I have two layers in a PostgreSQL database. The first layer contains points where events happened in Europe. The second ...
9 views

### How to choose the correct range for Moran's I correlogram with irregularly shaped areas? [duplicate]

This question was first ask on Cross Validated, but I think it might be better suited to Geographic Information Systems. First question here, so I apologize if it doesn't fit! I am doing correlograms ...
230 views

### Which training courses in geostatistics can you recommend?

I'm looking for excellent geostatistics courses all over the world, including online courses. In particular, I would like to learn more about the kriging method. Can anyone give me some suggestions?
161 views

### Calculating spatial correlation between features from two separate layers in QGIS

I am trying to determine whether the presence of large numbers of active duty military troops in an area is spatially correlated with higher/lower levels of violent crime. That is, are the areas ...
2k views

### How to implement bivariate Ripley's K function?

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 ...
37 views

### Spatial heterogeneity: What does spatially varying mean of a process exactly mean?

Imagine the following data set (from http://www.novaims.unl.pt/labnt/geosom/georepository/) which consists of three different regions: Obviously, blue points are more like to be located close to ...
261 views

### spatial and spatiotemporal analyses

I have a dataset that consists of 247 mosquito traps placed in fixed positions and sampled weekly for 23 weeks. I also have dengue disease incidence data (indexed to home address) during the same time ...
7k views

### Joining polygons in R

I am wondering how to join spatial polygons using R code? I'm working with census data where certain areas change over time and I wish to join the polygons and the corresponding data and simply ...
13 views

### Extremely high z-values for Moran's I

I made the following in advance: I aggregated population data to 100*100m Grids. Afterwards I wanted to find out, weather there is autocorrelation in the data or not. For this I applied the Moran's I ...
29 views

### Comparing different degrees of local spatial association

I have two data sets and want to compare/evaluate their degree of spatial association expressed in terms of the LISA statistic. The local Moran's I statistic gives for each point a (pseudo) p-Value ...
60 views

### Explaining different results from Ordinary Kriging and Universal Kriging?

When using either methods to create a surface from the same set of observations, these surfaces differ from each other. Visually it can be seen in the differences of the following contours ...
53 views

### Algorithm for spatial clustering?

I have a series of 2D maps with values ranging 0.0 to 1.0 spread all over. The algorithm that produces them is an application of the fractional Brownian motion. Each map measures 101x101 pixels or ...
24 views

### Best way to store, elaborate and query raster data [closed]

I have created multiple raster images with GRASS-GIS (~150Gb), that I'll need to multiply for a certain coefficient, and query the results that need to by saved just temporally. The portions of the ...
20 views

### Identifying the best OLS regression model

I have 10 independent variables to include in an OLS regression model. I know how to interpret the results and that for comparing models, the AICc value can be used, where a smaller value indicates a ...
145 views

### How to show statistically significant incident locations

First let me preface with I tried to search for this solution first but I don't really know how to word it and could not find any results so excuse me if this is a duplicate. I would like to know how ...
89 views

### Spatio-temporal statistical analysis

I need to perform an anomaly analysis in both space and time. I have 4 data parameters: latitude, longitude, time and temperature. What I’m trying to do is to find temperature anomalies that are ...
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 ...
65 views

### ArcGIS method for declustering a spatial dataset?

I have previously asked this question but perhaps was using the wrong terminology. I would like to run some type of cell declustering on a spatial dataset. Is there a tool for doing this in Arc? ...
41 views

### Problem replicating ArcGIS Grouping Analysis 'grouping effectiveness' statistic results

I posted this question over on Esri's GeoNet, but have not yet gotten an answer. Using ArcGIS v10.2.1, I have been using the Grouping Analysis tool to generate a range of clusters from my data. I ...
46 views

### Counting point objects near each feature in polyline layer of ArcMap?

I am having a little trouble finding a strategy for this. I have a polyline layer with Fiber segments, each have a FiberID. They are not unique, sometimes there will be two segments with the same ...
62 views

### Is median center more influenced than mean center by value outlier in ArcMap?

I noticed something strange or seemingly paradoxical in ArcMap 10.2.2. The median center is less influenced by spatial outliers than mean center, this is a fact. The thing is, I created 6 dispersed ...
44 views

### How to calculate Spatial Autocorrelation of grouped points in ArcMap 10.2.2

I have 32 points uniformly distributed with 7 attributes that comprises continuous values. I used the Grouping Analysis tool in ArcMap 10.2.2. I set 2 groups that have clear differences and are also ...
44 views

### Interpreting Statistical Analysis (Moran's I v High-Low)

I am currently examining the results of spatial statistics using Moran's I and High-Low clustering methods. I have used distance thresholds of 5 miles, 10 miles, and 15 miles for each. Moran's I ...
196 views

### Creating forest patches from land cover layer?

I have a land cover layer from which I've extracted the tree canopy class and set all values that are not tree to NULL. I've also converted it to a vector and exploded it to make single part features. ...
70 views

### R: Using Inverse Distance Weighting with the mapply function

I would like to find what are the optimal power parameters and number of neighbours for Inverse Distance Weighting (IDW) interpolation using the mapply command and the gstat package in R. The optimal ...