# 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.

85 views

### How to quantify the coverage area?

I have a task where I shall quantify AIS coverage in a predefined geographical area. The AIS is a system where automated positional data is sent from ships to base stations. I have AIS data with lat/...
69 views

### A way to measure whether two variables have similar spatial distributions?

I'm doing a project that's looking at a certain disease outbreak and vaccination in California counties using arcmap. I have aggregated data joins for disease outbreak rate, personal belief exemptions,...
117 views

### Using R to find attributes of spatial neighbors, especially with big spatial polygon data frames

If it's not too much, I have a specific question that leads to a more general one: I'd love thoughts on both if it's possible. First, the specific: I have an analysis involving census blocks and ...
116 views

### Spatial weight matrix with boundary effects in R?

I need some help to finalize code for a spatial weight matrix that uses a nearest neighbor definition within regions, but does not allow neighbors from across a political border. For example, ...
40 views

### Create statistics by features in QGIS [duplicate]

I've a polygon layer for parcels in a landscape protection area and a point layer, contains zoological data (e.g species, entities, etc.). How can I make a statics for each polygon, contains the list ...
82 views

### Obtaining size/dimensions (longest dimension/shortest dimension) statistics within a feature class or polygon shape file

I created several polygons within a feature class and wish to obtain statistics on: 1) Their dimensions (in terms of longest and shortest dimension) or size? Is there any tool in ArcGIS that can do ...
120 views

### Spatial autocorrelation analysis (Global Moran`s I) suspicious z-score

I have a doubt concerning the Spatial autocorrelation analysis Global Moran's I, in ArcGIS 10.2. I did the analysis with 3.372 features of a defined study area, and it showed that the features are ...
98 views

### Generating a predictive map with standardized variables

I have a model from which I am attempting to create a predictive map (in GIS, but I'm aware of some options in R). The response values are constrained to [0,1] using an offset term in the model (see ...
143 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, ...
63 views

### How to create a Planer Point Pattern in R using a Shapefile of point features

I have just started to learn spatial analysis of point pattern with R. On page 20 of this book, the "Swedishpines" dataset has been used for inspection purposes. However, I want to use my own dataset ...
85 views

### Spatial sampling design

I have some plots of land spread across the landscape. Sometimes a parcel is subdivided in different sectors. For each parcel (and, in case of subdivision, for each sub-section) the quality of ...
163 views

### Using spatial join in ArcGIS for Desktop?

I have two spatial layers of about the same (not exactly same) spatial extent. Layer#1 has about twice the number of polygons than layer#2 (in thousands). I am trying to calculate values for Field#X ...
100 views

### Visualizing variability in the size and shape of polygons

I am working with a data set of area restrictions imposed by criminal courts. These restrictions ban a person from entering a demarcated area. These restrictions vary in their size, shape, and ...
139 views

### How to center continuous raster layer by subtracting mean and dividing by standard deviation using QGIS raster calculator?

I'm trying to extrapolate a spatial model to a map in QGIS using the raster calculator. The model predicts the value of a pixel given the environmental conditions at this location (e.g. elevation, ...
415 views

### Computing Area Weighted Average on Rasters Using Raster to Polygon

I am using ArcGIS 10.3 for Desktop. I am trying to compute area weighted averages for polygons in a shapefile using values in a single band raster data set. The approach I am taking is that I am ...
425 views

### Python toolboxes missing (Can't use ArcGIS 10.2.2 toolboxes)

I was trying to use Hot Spot Analysis Toolbox on ArcGIS 10.2.2 but this error message appears: updateParameters Syntax Error Runtime error Traceback (most recent call last): File c:\program ...
188 views

### Spatial distribution of an invasive specie across a landscape : what analysis?

I'm studying the spatial distribution of an invasive specie introduced in a natural area. This plant, that thrives in sunlight, grows in thickets (patches). The population of my study site (10x10 km) ...
115 views

### How to aggregate values of different statistical areas that are overlapping?

Let's say I have one polygon layer counties with the polygons of administrative borders and another layer postal codes with the polygons of postal code areas. I have some statistical values per ...
122 views

### Drawing boundaries between discrete features based on attribute values in ArcGIS for Desktop?

There is a point feature class with a certain numeric attribute (let us say, populated places with population). I wonder if there is, in ArcGIS, a way to draw polygons such that the sum of the ...
347 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?
375 views

### Best Projection for Getis Ord Gi* Statistic Analysis

I am about to calculate the Getis Ord Gi* statistic for some rasters whose extents are global. In choosing a projection, do I want to preserve distance (e.g. equidistant) to obtain accurate ...
71 views

### Where can I find spatial data on Enumeration Area boundaries from the South Africa 2001 Census?

I am trying to locate spatial data for the boundaries of South African Enumeration Areas (EAs) from the 2001 Census. The links to the data from the 2001 census on the Statistics South Africa website ...
67 views

### Heat Map with species distribution [closed]

what I am trying to do is to generate a heat map depicting the spatial distribution of certain species found in a lake, in association with their sex. For example, species_a+male or species_b+female ...
348 views

### How can I create a valid probability map of species distributions based on presence/absence data from multiple quadrats?

I am somewhat new to GIS and only beginning to learn spatial statistics/analysis. I am an ecology grad student doing a before and after study on invasive plants and their responses to management ...
45 views

### What is a “value raster”?

I want to understand the concept of a "value raster" and if I can use it in neighbourhood statistics.
559 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 ...
120 views

### Choosing R package for discrete choice model?

I am at a loss as to which R package and approach to use for my modeling. The background is: I have a transportation survey dataset combined with many other GIS datasets. I am attempting to ...
90 views

### Low point density analysis

I'm working on a project for a conservation plan. Part of the plan requires that areas added for conservation have less than one structure per five acres (these are pretty large, mostly undeveloped ...
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### Arcgis 10-Sample selection

I am using arcgis 10 and I would like to select (in a manner of well spatially distributed) some of the polygons included in a .shp as testing population for a statistical analysis. The rest of the ...
123 views

### Optimal distance and power exponent in IDW

I want to apply IDW interpolation for my region of interest, and through leave-one-out cross validation I want to find the optimal values for the distance parameter and the power exponent. I know that ...
275 views

### Sublayers or Multiple Visualizations for CartoDB

I'm trying to learn a bit of CartoDB by creating a heatmap using crime data available on the city's website where the raw number of crimes are displayed for each police district. So far I've been ...
88 views

### Problem with ST_SummaryStats, ST_Buffer, and casting between geometry/geography types

I have a test raster that covers the world ((-180 90), (180 -90)). The SRID is WGS 84 (EPSG:4326). Values for cells in the north-western quadrant ((-180 90), (0 0)) are random integers in the range 1 ...
455 views

### Mean Center/Median Center tool providing points mathematically centered but physically appearing in the wrong location

To create population weights, I'm using the Mean and Median Center tool to find the center of our populations in census tracts. However, I've noticed that some of the points that are popping up are ...
96 views

### Using Ripley's K Function in ArcGIS for coral density along a transect?

I have some data from transects taken in a mangrove system. I want to analyze the spatial distribution /some sort of spatial statistics of how clumped/dispersed corals are along this linear transect. ...
217 views

### resize map and add points to it using R

I am working with spatial data UK. The map is plotted here. I want to resize the map and make it bigger and clear! here is my code LA <- readOGR(dsn =".", "infuse_dist_lyr_2011_clipped") ...
755 views

### Dissolve Polygons using R / join specific polygons

I have data in shapefile format :: UK_boundaries I am new to R and Spatial data as well, I am trying to join some areas to be as one area no line(s) between them. Based on my search I understand ...
85 views

### Kriging metal concentration with irregular set of sample points

I need to perform some interpolation to map a metal concentration around a platform. The distribution of my stations is not regular (see figure below where stations are the green points labelled with ...
88 views

### Selecting Features and Averaging Attributes

I currently have two point shapefiles, SHP A with approximately 75 points and SHP B with approximately 2000 points. What I would like to do is: 1) For each point in SHP A I would like to find the ...
289 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 ...
389 views

### Incomplete intersection area using gIntersection in R

I have two SpatialPolygonsDataFrame, one of them is the deforested area in the Amazon and the other is the city of Vila Rica, which is in the same region. I would like to calculate the total ...
214 views

### Kriging to calculate forest biomass?

I am trying to create biomass map using Kriging from ground sample point. I have about 150 and 53 point plot for dense and sparse strata. The data is not normal so I have transformed it. After ...
129 views

### Kernel density estimation across multiple UTM zones

I'm trying to compare the spatial distribution between two groups of fishing locations (for each of several different years) in the Bering Sea (lat's ~53 to 65N, long's ~ -178 to -158W. My preliminary ...
114 views

### ArcGIS compute nearest network neighbour for each point

I have a set of points and I would like to calculate a value for each point to indicate how 'clustered' to other points that point is. Distance to nearest neighbour (through a network) would do fine. ...
20 views

### implement aspect in least cost path analysis to account for downhill and neutral ground movement [duplicate]

I am creating a least cost path model for large species that migrate over large distances across a rugged landscape (elk, deer, etc.) To calculate movement cost I am using a slope raster but I ...
177 views

### Search Radius for Line Density [closed]

I have been working with GIS for many years but I am fairly new to the spatial analyst side of things. I am working with many satellite tracks for many different individual animals and would like to ...
221 views

### Statistically comparing two sets of coordinates [closed]

I have been given a task to compare two sets of points, one set being a set of predetermined points, on the other being a set of actual points that were taken in the field. I have to compare these ...
248 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. ...
143 views

### Extract mean value of a raster into a grid shape file [closed]

Hello guys I need your help I have a soil map of an island and a Grid polygon. I want to extract the mean value of the soil map to polygons squares of grid. I read this and this but Ι can't find the ...