# 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.

736 views

### Geographically Weighted Regression and categorical values leaving blank values after analysis

I am using Geographically Weighted Regression (GWR) in ArcMap 10.2 to look at the effect of environmental and human factors on lion occurrence in Namibia. I created a vector grid over the study area,...
251 views

### How to calculate “stop points” from a set of GPS tracklogs?

I have a set of GPS tracks pertaining to a cycling event that happened in the same day. I don't have much geographical information about the event itself, except for the tracklogs I downloaded from a ...
156 views

### Statistically compare two density maps?

I (will) have a modelled distribution and an observed distribution of animals. If I were to interpolate these position datasets to reflect some density distribution (perhaps using a kriging ...
670 views

### Do SAS Bridge to Esri and SAS/GIS extensions add value to Spatial Analyst and Spatial Statistics?

My organization uses SAS extensively, but has been increasing GIS use and capacity recently (that's why they hired me). I was asked to evaluate the two SAS GIS extensions Bridge to Esri and SAS/GIS. ...
89 views

### Finding routes in which more than one car passed (gps data)

I'm using ArcGIS 10.1. I have point GPS data of routes of several cars over a few days, and I want to find only the routes where more than one or two different cars passed through (Each GPS points ...
930 views

### how to choose stratified random sample on multispectral image

I'd like to choose random samples from multispectral image according to each Land Cover image. The multiband image has 70 bands representing land surface temperature data from MODIS. Land cover image ...
33 views

### help identifying the right spatial analysis tool

Let's say I have a set of N towns and a road network that connects the towns. I think some towns might an influence on other towns because they meet some criterion. I have a binary indicator of this ...
714 views

### What are the most efficient Geographic Weighted Regression packages?

What are the most memory efficient open source packages for calculating a geographically weighted regression (GWR)? I am in a situation where I need to do a geographically weighted regression on a ...
375 views

### Combining and displaying demographic data?

I am currently undertaking a demographic research project for my employer. We have the data on income, age, sex, language, transport etc and I have mapped most of it and created some thematics of said ...
2k views

### How to get count of non-NA raster cells within polygon using R

I've been running into all sorts of issues using ArcGIS ZonalStats and thought R could be a great way. Saying that I'm fairly new to R, but got a coding background. The situation is that I have ...
55 views

### What are problems & biases stemming from mathematics behind using Monte Carlo Markov Chain to make heatmap?

My buddy and I are using Monte Carlo Markov Chains to make a heat map - in the interest of rigour, and out of curiosity: "What are the problems & biases that stem from the mathematics behind ...
336 views

### What Spatial Analyst tool to use when comparing competitive species distributions?

A spatial analysis question: I'm trying to compare species distributions and specifically overlap between two species (Water Vole and European Rabbit) that are competitive species. I also want to ...
105 views

### mathematics of spatial diffusion models

There are different types of spatial diffusion such as contagious model, migration model, etc. What are the good books to learn about the mathematics behind these spatial diffusion models?
109 views

### Find nearest point (in file A) for every point (in file B)

I have 2 csv files both with 3 columns: variable, lat, lon. Let's call them file A and file B. File A has 100 values for variable (in this case city), File B has 100,000 values for variable (station ...
219 views

### How can I choose values from stacked raster images according to location of ROI

Before I choosed ROI on land surface temperature (LST) images and obtained pixel values of LST. Now I need pixel value of another images which are stacked multi-band image. My main purpose is to ...
56 views

### Is there any statistical method to proof if the method is suitable or not [closed]

I have recently done a phenological study using threshold method from MODIS NDVI images. But I'm suffered that I don't have any situ observation (ground truth) data to do validation. Is there any ...
472 views

### determining what polygons intersect another layer

I am attempting to establish what spatial relationship exists (if any) between two layers. I have two layers - one is a road network with a buffer of 500m, and the other is a collection of polygons ...
950 views

### Making Unique ID field for Ordinary Least Squares in ArcGIS Desktop?

I need to perform an OLS (Ordinary Least Squares) but ArcGIS asks for a unique ID field. I have a field which would be the right candidate, it's a FIPS number (12 chars), which I have made a number, ...
153 views

### Mann-Whitney U test for rasters

I'm doing a Mann-Whitney U test to compare two very large samples (sample size 1 = 13250; samlple size 2 = 38871) originating from a shapefile with 52121 features. I know t-tests are not recommended ...
284 views

### Interpolating points observed with different time duration

I am doing spatial interpolation with a group of points. Some points have complete observation of events: for a period of 24 hours we have observed N events in each point. These points have N ...
91 views

### Summary Statistics tool for Mean Z values

I'm using ArcGIS 10.2 The summary statistics tool is not functioning in the way that I want. I made an elevation layer that is a DSM, and then in my buildings layer I determined the height for ...
437 views

### How to get “p value” for time series data to detect significant change

I have yearly maximum NDVI data (1982-2008) and extracted all value to Excel. Also calculated slope value for each point during the 27 years. All of you know the slope value represents changes per ...
253 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 (...
145 views

### How to choose pixel values according to each land cover class?

I would like to do following steps using two types of images (precpitation and Land cover image): select pixel values of precipitation image within each land cover classes calculate total amount of ...
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. ...
461 views

### percent of total population is x distance from nearest point (ArcGIS 10.2)

I'm getting my but kicked by some statistical analyses in ArcGIS 10.2 and need a bit of assistance. I have two data sets. One is a raster which represents the population of a country at 100m ...
73 views

### What statistic / process should I be using?

I am trying to determine the best process to analyse some predicted water levels against observed values at specific points. I can do this simply as 1 to 1 relationship to get a r square. I would ...
90 views

### Exploratory search for clusters in point data

This is a more conceptual than practical question and is about exploratory cluster identification. While there are very specific meanings in the geography canon as to what they are, in economics they ...
344 views

### What does the “Standard Distance” output from the spatial point pattern analysis in QGIS 2 represent?

I have a cluster of points and I am using the Spatial point pattern analysis tool from the processing toolbox in QGIS 2. I am having trouble understanding what the "Standard Distance" output is? It ...
2k views

### how to do change detection in ERDAS

I'd like to ask a really simple question. I want to obtain the size of unchanged, decreased, and increased area etc (just like shown in image below) from 2 classification images in 2000 and 2007. How ...
702 views

### How to use a polygon grid to calculate statistics on line and point features

What seems a simple task but I can't find the right tool to do it. I have a polygon grid cells and say a point feature class. I want to be able to create a table that contains the grid cell ID and for ...
109 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 ...
277 views

### How can I know how many percent of area changed between 2 time step in arcgis?

I'd like to ask how to do change detection in ARCGIS? I need an image to show how many percent of area in class has been changed between 2 years? for example in output image, red is the area that has ...
2k views

### How to create mask file from shapefile using ArcGIS for Desktop?

I have a shapefile of Lakes over my study area. Each polygon has attribute information of each lake, name, shape etc. Actually I want to eliminate all lakes from analysis. In other word, I want lakes ...
889 views

In my current R project I'm using the ggmap package to download and display maps. What bothers me is that you need internet access to load maps from google etc. I'd like to load a map from the ...
379 views

### How to find buffer radius around raster cell that covers a defined sum of raster cells?

I want to do a neigbourhood analysis on some raster data. I need to know how big a circle around each raster cell must be to include a certain amount of specified raster cells. Let's say that for ...
672 views

### How can I define hierarchical levels in eCognition

I'd like to define classes with 2 levels. Firstly I'm gonna classify some broad classes such as forest, grassland in a level 1. Furthermore, I'd like to classify these classes into some sub-classes ...
3k views

### Spatially join large raster to polygon shapefile

I have a large raster file with elevation data. From this raster, I would like to infer the average ruggedness for different geographic zones (like countries). I have the "countries shapefile" as a ...
283 views

### Relational operation in eCognition

Is there anyone who has a experience with relational operation in eCognition. I'd like to ask 2 questions related to eCognition. 1. How can I classify the pixel values between 0.23 and 0.46 as a class ...
660 views

### How can I statistically calculate the “real” road from a set of GPS tracks

I participate in a long-distance cycling club, and we started to collect GPS data routinely from our riders. My interest is to calculate "the real trajectory" for future events based on accumulated ...
524 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 ...
183 views

### How to Deal with Overlapping Coordinates in Statistical Analysis

I decided to make an archaeological map about certain tombs distributed in the area of Crete and make some statistical analyses using the spatial statistical tools of GIS. Specifically, I'll be ...
1k views

### How to split a polygon using R

I have an irregular polygon which is a spatial object. I want to divide it into multiple polygons (say, n=25) with equal height. To show how I want to divide it, I've plotted grids on the ...
247 views

### Interpolating lots of points with seemingly good spatial density

I'm using Arcmap 10 and I have scattered points (denser in an area). Each point represents a thickness value of a simulated avalanche deposit. I want to get a raster from this points which I will ...
1k views

### Using Regression Trees in ArcGIS

I have a follow up question to Statistical analyses for survey against raster? I have a very similar problem as the initial poster David. I am creating a multivariate model from raster data in order ...
892 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 ...
706 views

### Comparing choropleth maps statistically

I have several sets of choropleth maps showing ranges of poverty by census tract, each using a different poverty measure. All of the maps use the same categorical ranges to define poverty status. The ...
353 views

### How to compare spatial patterns (crime cases vs population)?

I am looking for a way to statistically compare two spatial patterns in shape polygon data (not point pattern analysis). Let's say I have a city map divided in neighborhoods (barrios), in shape ...