# 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.

662 views

### How to quantify unevenness of polygon boundaries?

I have two polygons: Polygon 1 and Polygon 2. Using two metrics, area and perimeter length, I want to express quantitatively that Polygon 1 has a more uneven/jagged/irregular perimeter than Polygon ...
559 views

### statistics by rectangle (raster image)

I have a shp file with some rectangles and I want to extract statistics within these areas from a raster image. I prefer ArcMap 9.3.
541 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 ...
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?
31 views

### Assigning the modal average based on points within a polygon

I have two layers: Survey Points Habitat Multi polygon The Survey points contain the field sensitivity I want to assign a number to each polygon based on the modal average sensitivity. This ...
81 views

### Looking for similarity analysis 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 ...
798 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 ...
45 views

### How to interpret 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 that ...
410 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 ...
588 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 ...
60 views

### Create shapefile connecting points “as the crow flies” in R

I have a set of locations (with latitude and longitude). I know how to get the distance between these points, but I want to create a line that connects them with the shortest path ("as the crow flies")...
79 views

### Statistical Analysis of Climate Data

I am doing a study on how a changing climate is influencing the spread of an invasive species of moth. I have climate data in the netCDF format which I have made into both rasters and point ...
38 views

### GIS Least Cost Spanning Tree in R

Is there an R package/function that computes a least cost spanning tree given a shapefile or vector containing the latitude/longitude of each point and a raster file that contains the cost of ...
33 views

### Multiple raster - same extent - smallest overlapping area

Within ArcGIS (10.1) I have multiple raster files, for which I have to calculate different statistics, based on the total size of the raster. EDIT: The raster have the same extent on a coarse scale ...
15k 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 ...
110 views

### Which statistical methods to compare the spatial distribution of two different variables in two raster maps?

I am working with two global raster maps using the R Software (original file: netCDF for map 1 and GeoTIFF for map 2), with a resolution of 5 min of arc. Map 1 contains data on the share of the land ...
26 views

### Running local Moran's index in all fields automatically?

I want to use the local Moran's I index in ArcGIS. I have a table/layer with 50 columns. Can I execute moran in all fields of this table automatically or do I have to run the tool 50 times?
920 views

### How to calculate median value of polygon from points in ArcGIS?

I have a point layer coming from LIDAR data containing x,y,z and intensity values. On the other hand I have a layer containing several polygons. All the points are inside the polygons. I need to ...
40 views

### Trouble shooting Incremental Spatial Autocorrelation/Hot Spot Analysis

I'm trying to do a spatial analysis of rural school closings in Brazil (ultimate objective to do OLS/GWR). I have census data from 2005 and 2014, from which I've calculated the relative percentage of ...
28 views

### What is the difference between spatial regimes and spatial heterogeneity?

Let me cite excerpts from the GeoDA-Gloassary (https://geodacenter.asu.edu/node/390) Spatial regimes: Spatial regimes are a form of spatial heterogeneity, which implies structural differences ...
29 views

### What to do with the intercept output from regression analsyis?

In ArcGIS I use global Ordinary Least Squares Regression (OLS) models and Geographically Weighted Regression (GWR) models to analyze the relationships between independent variables and my dependent ...
93 views

### Categorising Point Clusters

I have a point dataset of solar farm locations. The points are grouped according to which substation they feed into (see below). I would like to test the hypothesis that electrical output ...
56 views

### Problems with moran spatial autocorrelation tool

I´m trying to run the Moran's I spatial autocorrelation tool but there is an error: updateParameters Syntax Error: Runtime error Traceback (most recent call last): File "c:\program files (x86)\...
779 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 ...
63 views

### Extract raster values around point features with kernel

I have a point layer of known landslide locations, and a raster layer (30m) of vegetation cover (categorical). My goal is to extract the prevailing raster value around the point locations. Almost all ...
3k 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. ...
219 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. ...
258 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 '...
61 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 I'...
64 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 ...
15 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. ...
122 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 > M)....
56 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 ...
296 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 ...
22 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 ...
24 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?
145 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, ...
225 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 ...
148 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 ...
676 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 ...
25 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 ...
31 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 ...
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 ...
367 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?
535 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 ...
41 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 ...