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.

101 views

Estimation of values for unsampled points

I want to measure biomass on a coastal mudflat. I can only access points inside the polygon. Are there any methods available that would allow me to estimate values of the points outside of the polygon,...
94 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 ...
195 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 ...
100 views

Interpreting Global Moran's I and should I krig?

I am trying to weigh up if kriging (or cokriging) the residual error from my model is a valid approach. My first step was to compute whether the error is spatially autocorrelated. I have done this ...
117 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, ...
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 ...
298 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 ...
475 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 easy-...
157 views

How do I statistically compare positions from two track datasets?

I have two datasets with positions that I need to compare. One would be the "observed" positions (someone took the GPS positions manually) and the other one was calculated using a software. To use ...
130 views

Quantifying polyline overlap

I have a set of regions and would like to quantify the degree to which the boundary of these regions are situated on/near rivers. I have turned the regions from polygons to polylines in arcgis 10.1 ...
175 views

Ways to measure similarities/congruence of tracks (point features) in ArcGIS

I have a sets of GPS coordinates recorded while tracking different cross country runners. What I would like to do is to compare how similar the tracks of the individual runners are. Is there a test ...
168 views

How does Zonal statistics handle pixels that are on the border of the polygon?

I am using the plugin zonal statistics to calculate the sum of the raster cells within polygons. How does this plugin handle pixels that are on the border of the polygon, are those cell values ...
357 views

How do I access layer attributes from within QGIS' manageR plugin?

This is probably a fairly basic question, but searches for manageR come up with a lot of noise, and there's no manageR tag. What I'd like to do is load the attributes from a particular field of a ...
40 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 ...
17 views

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. ...
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 ...
100 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 ...
27 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 ...
159 views

Spatial Autocorrelation tool vs. Incremental Spatial Autocorrelation

When you run the Spatial Autocorrelation (Monrans I) tool, you have the option of setting 'Conceptualization of Spatial Relationships'. This option isn't available for the Incremental Spatial ...
127 views

Geographically weighted regression for GPS tracking data

I am hoping some one might be able to help me with the following question. The study I am working on has GPS locations at 4 hourly intervals of 5 lions in 3 National Parks over roughly 2 years in ...
256 views

AGI STK Server alternative

AGI has a server product called STK Server that exposes REST services to perform satellite acquisition planning. However the cost is astronomical \$200k+ (pun inteded). They also have STK components (...
21 views

Setting the number of bars in a histogramm

I am using qgis' 2 "Statist" to build a histogramm for my data. I see that I can set the band width of the bars, but it seems that "Statist" does not provide the option of setting the number of bars. ...
110 views

Determining spatial cluster of park types in ArcGIS

Question 1: I am trying to determine which (if any) of my different park types are spatially clustered across my study area (city boundary). There are 162 total parks, 9 nominal categories (which ...
526 views

Problems with spatial autocorrelation in Geographically Weighted Regression (GWR) analysis

I have conducted an Ordinary Least Squares (OLS) and Geographically Weighted Regression (GWR) analysis in ArcGIS where I have tried to predict biodiversity patterns in an area. When I examine the ...
367 views

About zonal statistic function in ARCGIS

I calculated zonal statistic in Arcgis to get max/min value of each LC types. Broadly, LC image include forest, grassland, waterbody etc. But output max value of zonal statistic function give me 0.972 ...
15 views

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 ...
32 views

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 ...
13 views

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 (...
15 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 ...
18 views

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 ...
24 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?
25 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 ...
26 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 ...
58 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 ...
54 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 ...
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 ...
32 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 ...
75 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 (...
75 views

Using linear regression for geospatial data?

Say, my database has three columns. A: county (300 rows with 300 counties as index), B: X (some independent variable in continuous scale, which is the average of everyone in that county), and C: Y (...
20 views

Metrics and features for comparison of aggregated trail dataset

I have hundreds GPS traces generated by cars for single road in the city from direction A to B. And I have hundreds of GPS traces generated by people which organized in trail in the mountain from ...
133 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 ...
104 views

Performing Regression Analysis using ArcGIS for Desktop?

I am trying to perform regression analysis using road accident data using ArcMap 10.1. The accident data is a point file for all accidents with information on the date the accident happened, time, ...
119 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 ...
99 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 ...
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 ...
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 ...
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. ...
109 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 ...