# 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.

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### 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 ...
145 views

### Grouping Analysis (Clustering) of polygons with streets as borders in ArcGIS?

I have a question about the Grouping Analysis Tool in ArcGIS. Is it possible to use streets as spatial borders for the groups? I want to group a city district autmatically with multiple attributes, ...
154 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?
229 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 ...
43 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 ...
45 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 ...
165 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 ...
44 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.
341 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 ...
74 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 ...
68 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 ...
87 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 ...
166 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 ...
66 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 ...
202 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 ...
83 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. ...
139 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") ...
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### scenarios to make multiple data maps comparisons?

I'm using Leaflet (and several of its plugins) to make a custom SOLAP solution and i want to offer to the user, the possibility to make data analysis and comparison between multiple maps, my question: ...
478 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 ...
70 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 ...
73 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 ...
160 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 ...
253 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 ...
168 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 ...
93 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 ...
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### 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. ...
17 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 ...
128 views

### Search Radius for Line Density

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 ...
143 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 ...
169 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. ...
120 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 ...
81 views

### spatial relation between springs (points) and geological faults (polylines)

In ArcGis 10.1 (advanced license), I have digitized the geological faults (polylines) and the location of water springs (points). Since, relying on literature, there is a potential connection between ...
178 views

### How to deal with data which are not normally distributed when kriging?

I'm a novice with advanced spatial interpolation, and I'm trying to use the Geostatistical Analyst to interpolate a surface based on borehole data, using Ordinary Kriging. The help file explains how ...
31 views

### Metrics of change between vector datasets

I have an old and a new set of parcel data which I'm looking to compare. I'm looking to compare changes in individual parcel geometries, so boundary/corner adjustment. Currently each parcel we have ...
52 views

### Clusters of Same Size? [duplicate]

I am attempting to use the Grouping Analysis tool in the Spatial Statistics (in ArcGIS 10.2) to group state high schools (points) together based on enrollment and location. Is there a way to make ...
91 views

### ArcGIS 10: How to mask a raster by using extract by mask tool If the feature mask is larger than the raster area?

I have a problem to mask the the raster which has values ranges -0.73106217384338 - 0.94593381881714. These values have been derived by using equatin (B3-B4)/(B3+B4) from Landsat band 3 and band 4 ...
263 views

### Single Tree detection

I was wondering how I could extract "crown area" of single trees in a forest from a high-resolution image with only 3 band (RGB) in ArcMap. ( No NIR to use NDVI as any threshold). I need a fast ...
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### How to see whether a set of postcodes have a typical distribution to the whole postcode population of UK?

For my dissertation I have a dataset of postcodes of 9984 that I am converting to coordinates atm. I looking to find whether this dataset has a 'typical or 'atypical' spatial distribution compared ...
503 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 ...
167 views

### Calculating quantile values over a stack of images with grass gis. Help needed on r.series

I need to calculate the values for the 25%, 50%, 75% and 90% quantile over a series of rasters (time series of ndvi values from landsat). I am exploring the r.series command in Grass GIS, but the ...
25 views

### Trying to produce a map of Household behavior with identified explanatory variables held constant/equal

I have a map of the dependent variable, median household vehicle travel, and independent household characteristic variables, median income, mean household size and median age, aggregated to census ...
182 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 ...
151 views

### Statistical Analysis using ArcGIS

I have points containing data on temperature from 1951-2000. All data have X,Y coordinates. I have raster files in the same period. Two data sets have different data processing hence different values ...
214 views

### Implementating Analytical Hierarchy Process with ArcGIS 10.2 for Desktop?

I want to use the AHP in arcmap 10.2. I have tried using the arcscript available from http://arcscripts.esri.com/details.asp?dbid=13764 Which was designed for Arcmap 9.2. I was able to get as far ...
554 views

### Capabilities of the Analytical Hierarchy Process (AHP) in conjunction with the weighted overlay tool

I am making a prospective map of fossil deposits using the "Weighted Overlay" ArcGIS tool. Input factor rasters are mostly topographic in nature (elevation, roughness, TPI, etc). Initially, I had ...
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### How to Predict demand on a bus route, considering variaton in kms and price?

If there is a route (line) modification, I mean change on distance; and also a change on the price for the user. How can I calculate the demand on the next year, considering seasonnality. What would ...
375 views

### Summarize the total area of land use polygons within map sheets - how?

I would imagine that at least some of you have encountered similar problems to mine and I´d like to hear how you solved them. I have a map sheet index (a grid as a shape file) covering a large area. ...