# 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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### “Downsample” a dense grouping of points onto a sparse grid

I have a SpatialPointsDataFrame with thousands of datapoints in a relatively small geographic area. The points are grouped around regions of physical measurements and are hence irregularly spaced: ...
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### Examining spatial and temporal correlation between points and polygons

I have 2 kinds of events I want to examine correlation between, lightning strikes and earthquake events. The lightning strikes are defined by lat lon points and a timestamp, whereas I have represented ...
39 views

### Rasterizing in R - how do resolutions work? (e.g. population within a circle)

I'm creeping into building surfaces - useful for a number of public health projects - and can't seem to make sense of what's happening with the resolution and raster building process to get what I ...
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### Gstat krige() error: Covariance matrix singular at location [917300,3.6109e+06,0]: skipping

Recently, I am facing a strange problem when using krige() in gstat library. This error was not there a few months ago because I am using the same code with the same data that I successfully used ...
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### Statistics for geo-referenced floristic inventory

I have a dataset consisting of several thousand geo-tagged photographs of flowering plants (dozens of families, roughly 240 species). The inventory was conducted monthly over three years along a ...
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### Exponential function variogram sill values

I am using gstat package for deriving a variogram using exponential model. My R code goes like this: g <- gstat(id= "HV",formula=HV~X+Y,data=vari) vari.var <- variogram(g) vari.var plot(vari....
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### Half of Earth with most landmass [closed]

About 71% of the Earth's surface is covered with water and the remaining 29% is landmass*. If you could theoretically cut the planet in half, with the objective of producing a half with the most ...
72 views

### How to analysis the spatial distribution similarity?

There are three different data source aiming at atmospheric chemistry research: Simulated concentration of ground level air pollutant Satellite retrieved concentration for the same area. ...
47 views

### Is there a spatial gradient in my data

I already posted the question here, but I thought that maybe it is a question for GIS as well. I have a grid with densities of one animal and would like to find out if there is a spatial gradient in ...
35 views

### Spatial Statistics in mapinfo 15 64 bit

How can I get spatial statistics on my vector (tab) data in MI 15 64-bit. I just need to see total line lengths, areas etc as appropriate. From the MI help I tried the following To see the ...
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### Can I statistically smooth attributes spatially (using distance/surrounding polygons) in ArcGIS?

I have Census Areas with some of the Census attributes. Is it possible to take an attribute, for example, percentage of people in full time employment, and derive a spatially smoothed version of the ...
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### Find and filter points within a variable radius

I have a set of projected spatial points (x,y,id,dist,value) that needs to be filtered. For each point I have to find the other ones falling within a variable distance. For each selection, I need only ...
34 views

### How to Convert 3D coordinates to 2D coordinates for R-Tree?

I am trying to implement a bounding box via a spatial index and get an error stating that I must either provide coordinates as either (minx, miny, maxx, maxy) or (x,y) for 2D indexes. I've tried ...
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### Making new variable that is average racial composition in neighboring tracts using ArcGIS for Desktop?

I am a Public Health PhD student doing a mixed methods thesis - and the spatial analysis is not my strong suit. I want to figure out if there is a way to generate a new variable which would be the ...
37 views

### missing buffer values when using zonal statistics in ArcGis

I am using zonal statistics in ArcGis 10.2.2 to calculate the mean value of fire frequency within 1km buffers. However, I have noticed that this is not being calculated for all of my sites? There are ...
58 views

### Calculate Statistics along a Linear Feature

I have a linear feature class (road network) that is split into segments less than 2 miles in length. Each segment is assigned a value. I want to calculate a distance weighted sum in some manner such ...
58 views

### Using timeslider in QGIS to show census data per year?

I have several shapefiles with the same geographic extend (in my case: Berlin and all its administrative subareas) and statistical (census) attribute data for every subarea displayed trough a ...
47 views

### Hot Spot Map in ArcMap and MATLAB

I've tried out the Hot Spot Map tutorial for ArcMap, which is working just fine, and I'm now starting to make some modifications so that it fits my data sets. Instead of aggregating the points as in ...
39 views

### Reducing number of attributes (classes of marks) in marked point pattern using R?

I have a marked spatial point pattern loaded in R (from Shapefile). This dataset has 4 different "classes" of marks: class A, class B, class C and class D. Each class of marks is categorical. One can ...
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### How to statistically compare a point pattern to a model?

I have a point pattern which represents the damaged buildings following the earthquake. These data were created by online volunteers therefore I want to examine it's possible quality. Since there is ...
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### How to define a study area for Ripley's K analysis?

I have a spatial point pattern which spans across multiple districts in the country. Now I want to examine its pattern using Ripley's L function. I know that Ripley's L function is used for ...
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### What is the approach for comparison two spatial point sets on the global scale?

I have to point sets, both of them dispersed over my study area, which counts several districts. Now I want to find a way how to compare them between each other using spatial statistics on a global ...
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### Bivariate Moran's I and LISA statistics using two diverse variables at different time

I'd like to use the bivariate Moran's I and LISA statistics using two diverse variables at different time. For example, Population in 1990 and firms' localisation in 2000. Please, I would like to ...
42 views

### Calculation of coordinates

How can I merge some small regions to create big regions? Then how would I be able to calculate the coordinates of these new regions?
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### Goodness of fit of variogram model using geoR

How can I find a measure of goodness of fit (let's say an R2) of a model fitted to a variogram by the function variofit using the geoR package? The only value I have is the "minimised weighted sum of ...
81 views

### Calculating total area overlapping specific raster DEM color interval whose boundaries are confined by another vector?

I know this sounds quite difficult, but maybe it isn't for you or at least it shouldn't if I explain it correctly. (I'm using QGIS 2.14) I'd like to know to calculate total area overlapping a ...
30 views

### Tool to determine the trend of data point positions? [closed]

I am looking for a tool that can determine the dominate trend or maybe a histogram of trends for data point position. Basically if I have somthing like this:s. Then I want a tool that will tell me ...
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### R: Voronoi tesselation from long/lat data?

I want to create a SpatialPointDataFrame and Voronoi Tesselation from my .csv data downloaded from EPA, available here: http://uloz.to/xboQc7cu/no2-calif-csv I convert my data in SPDF format in 2 ...
42 views

### Formally testing whether building type tends to be close to another building type?

In arcGIS 10.1 (advanced licence), I have two polygon shapefiles, each representing two different types of building (let's call them A and B). Each type is actually used for two different purposes. ...
38 views

### Nearest Neighbor Analysis for route events

I have events that are on routes. You can think of it as accidents on a highway. I want to do some spatial statistics on it. The road is an M enabled feature class and decision makers want logical ...
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### How to apply Edge Correction in ArcGIS Average Nearest Neighbor

I am using ArcGIS 10.3 with the tool Average Nearest Neighbor to describe the data. I want to avoid mistakes caused by Edge Effect. In the Ripleys K Function tool there is an option to control that (...
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### What is (if there's any) difference between MAUP and Edge Effect

I heard both the term MAUP and Edge Correction in association with Spatial Statistics, zoning/quadrats, demographics etc. Is there a difference between the two? What is the difference then?
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### Average Nearest Neighbor does not have all the options

I have a point feature class that I used the Average Nearest Neighbor from the ArcGIS software to calculate the pattern. ArcGIS produces output chart that says whether the data is dispersed, random ...
52 views

Is there a tool / toolbox in ArcGIS to create quadrats on a population? I have a point feature classes with 1 billion points (divided to 10 almost equal feature classes) that I want to take samples ...
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### Average Nearest Neighbor tool extreme restuls for different area?

I'm using the "Average Nearest Neighbor" tool in ArcGIS 10.3 to calculate whether my point feature class is clustered, random or dispersed. One of the parameters is area. I tried putting different ...
34 views

### Graphic output for Ripleys K function

I am using ArcGIS to calculate Ripleys K function using the "Multi-Distance Spatial Cluster Analysis (Ripleys K Function)" tool on a point feature class. I can see a table output but want a graphical ...
22 views

### How to work with Spatial Autocorrelation (Morans I) on equal weighted point

I have a point feature class. All points are the same, it's not weighted. I want to use Spatial Autocorrelation (Morans I) tool but it only takes a field for weight. I tried fooling it by adding a ...
41 views

### Standard deviation of point pattern

I am using ArcGIS software to create a Standard deviation of point pattern, and I know whether Ii need to expect a circle or an ellipse. Is standard deviation in that context always circular? And if ...
21 views

### Is there really random distribution of points? [closed]

I'm just wondering if there is really such a thing as "random" in geography? To me it always seems like everything has a reason: examples: vegetation does not just randomly grow whether and ...
16 views

### When would I use K analysis over NNA?

I'm working with the dataset Redwood (62 redwood trees in a 23^2m square). I intend to test whether these are random or not. In what cases would I prefer Nearest Neighbor Analysis and in what cases ...
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### Calculating intensity of a 0…1 scale

I'm trying to come up with the Intensity value for the Cells dataset (Diggle 1983). This dataset has coordinates from 0 to 1, probably percent, there is no actual unit to it as I think it was taken ...
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### transforming 0 to 1 coordinates to other measurement

I am not experienced with ArcGIS and trying to perform some analysis on using the Statistics toolbox. The dataset I'm using is the redwood dataset used by Diggle 1983. An example can be found here. ...
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 ...
62 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")...
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 ...
34 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 ...
80 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 ...
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?