Questions tagged [moran-index]

Measure of spatial autocorrelation

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Moran's I Statistic for skewed data

I'm trying to determine whether there is spatial autocorrelation in a set of data. I am using Moran's I statistic to test for spatial autocorrelation. The data was point data (instances of an event at ...
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1answer
61 views

How can I extract Moran's I from buffered pixels withins raster

I have a raster with NDVI and I have a dataframe with coordinates I want to extract stats from at a 125m radius. extract(NDVI,coordinates,method='simple',buffer=125,fun=mean) this works for most of ...
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1answer
53 views

Constructing a raster with Moran's I close to -1

I wrote a script that produces three raster objects and computes their local and global values for Moran's I. The rasters exhibit regular, clustered and randomly distributed data. I would have ...
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21 views

If there is no spatial autocorrelation, should the spatial cluster detection be performed?

I have a regional count data of disease incidence. First, I calculated empirical Bayes estimate of standardized morbidity rate. Then I performed global Moran's I to check for spatial autocorrelation ...
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0answers
28 views

Local Moran's I on spatially heterogeneously sampled dataset

I have a dataset where points are sampled in space. Values are attached to the points, and I'd like to check if these values are correlated in space with Geoda's local Moran's I. However, the sampled ...
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29 views

Accounting of strength of spatial autocorrelation between some grocery stores in distance 500 meters

I'm analyzing sales one supermarket chain and I want to know how other neighborhood stores influence on turnover store. I have data about other stores and their location. As a result, I need to get ...
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1answer
141 views

Moran's I z-value in spdep

I wish to incrementally find the neighbour distance which maximises Moran's I test statistic. I have read that the I values are not comparable across varying spatial weight matrices but that the z-...
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2answers
92 views

Computing Moran's I from a ggplot map

In an effort to detect spatial autocorrelation using Moran's I in some variables, I was wondering how I could go about creating a polygonal shapefile from a ggplot-created map. My data lists multiple ...
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1answer
81 views

Use of Getis Ord and Moran's I

I have dataset with around thousand geocoded datapoints, each having specific pollutant and its value assigned to it (so it is all in one dataset, some of the datapoints(stations collecting data) are ...
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1answer
51 views

How to interpret spatial random permutations against the observed value of the statistic (PySAL)

I have a map for which I calculate the value of the Global Moran's I. With the use of PySAL, there is also an option to do a computational inference. The result of such analysis is shown below. From ...
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1answer
3k views

Moran’s I (spatial autocorrelation) in QGIS or SAGA?

Is there a way (plugin/processing tool) to calculate Moran’s I as a measure of spatial auto correlation of a point pattern in QGIS or SAGA?
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1answer
162 views

Find optimal distance band after running Incremental Global Moran I with PySAL?

My observations are points along a transect, irregularly spaced. I aim at finding the distance values that maximize the clustering of my observation attribute, in order to use it in the following ...
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1answer
242 views

Defining strength of Moran's I

I have calculated Moran's I in R and reject the null hypothesis in both data sets, there is evidence of strong spatial autocorrelation. However, how do I compare the two? First set: Moran I ...
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1answer
179 views

Fixing colors of LISA Cluster maps from Pysal?

I am using the LISA Cluster package from Pysal to create a LISA (Local Indicator of Spatial Autocorrelation) map. As the example of the documentation shows, the color lightblue is used to identify ...
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1answer
94 views

What does first requirement for LISA statistic mean?

According to Anselin, a LISA statistic have to satisfy two requirements: The LISA for each observation gives an indicator of the extent of significant spatial clustering of similar values around that ...
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1answer
460 views

What unit is returned by the ncf::correlog function?

I'm using the correlog function from the ncf package to figure out the distance between points at which spatial autocorrelation isn't detected. I was wondering what unit was being returned in the ...
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1answer
90 views

Calculating Moran's I for buffers of forest cover?

I'm trying to figure out if buffers I have created in ArcMap (measuring percent forest cover in a 1 km distance from a land use map within the buffer) around points at which I will be collecting ...
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1answer
793 views

Compute Moran's I on more than one attribute

I am trying to compute global Moran's I to check for spatial autocorrelation among areas of a city. I am using python, in particular geopandas and pysal. My geodataframe looks like: District_name|...
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1answer
106 views

Geographically Weighted Regression with overlapping polygons

Is it statistically correct (or possible at all) to calculate a spatial regression with (partly) overlapping spatial areas? I have market areas as the spatial unit with different sociodemographic, ...
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1answer
621 views

Moran's I: Selecting the best option for conceptualizing the spatial relationship between # births & county locations

I'm using Moran's I to see whether there are clusters of births rates present among the 83 Michigan counties, and, if so, whether the clustering is statistically significant. The inputs are the ...
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1answer
177 views

Output feature missing when using Cluster and Outlier Analysis (Anselin Local Moran's I) in ArcMap?

I am currently working on a project which I must calculate Anselin Local Moran's I. I am using polygon features and ArcMap 10.4.1. Here is my problem: when I am trying to run the command ArcMap shows ...
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524 views

LISA (local indicators of spatial association) p values in R versus in Geoda

When calculating LISA statistics in GeoDa versus using the localmoran() function in spdep, the I values are nearly the same, but the p values can be quite different. I know the two programs calculate ...
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2answers
2k views

Moran's I on 2D arrays/rasters?

I would like to apply Moran's I spatial auto-correlation measure to 2D arrays or raster files in Python and I am wondering if there is an available implementation for it. I know Pysal offers an ...
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1answer
2k views

Choosing value of Moran's I to say existence of spatial correlation?

I am a GIS beginner. Usually we use Moran's I to evaluate spatial autocorrelation. Everyone knows the Moran's I coefficient ranges from -1 (uniform) to 1 (clustering); I = 0 means no correlation. If ...
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2answers
464 views

Moran test results - rejection of H0

I started with a linear model (lm) and I want to make some spatials models so I tried first a Moran test to lm. Can we reject the null hypothesis with a p value of 0.11 in order to continue working ...
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1answer
1k views

Spatial weight for PySAL from a geojson file or geodataframe?

I want to calculate the Moran I value of a geojson file through python. Recently I am trying to use pysal and I find that I need to get the a spatial weight to realize it. But from the official guide ...
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1answer
1k views

Why Spatial autocorrelation (Global Moran's I) is producing a p value of 0?

I am undertaking spatial autocorrelation (Global Moran's I) in ArcMap 10.3. The p value returned is 0, does this just mean its extremely significant or is this an incorrect result?
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428 views

Why are Moran's Index calculated in GeoDa and ArcGIS different? [closed]

I recently have found that the Moran's Index calculated in GeoDa and ArcGIS are different based on the same data and the same spatial matrix. For example, this is my testing shapefile, a point ...
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1k views

Calculating spatial autocorrelation of raster values?

R is perfectly willing to compute a Moran's I statistic (and probably all of the other autocorrelation metrics) for a raster. As best I can tell, PySal and ArcMap's autocorrelation tools specifically ...
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1answer
1k views

Significance test for local Moran's I in R raster

Does anyone know how to produce the p-value and z-scores in order to do a significance test in the local Moran's I values obtained by the following code? The input is a remote sensing image: The ...
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1answer
696 views

Interpreting GWR Result - Issue

I used the Geographically Weighted Regression (GWR) to find out which independent variables lead to crime and how they vary over the space. After a literature review, I ran a global Ordinary Least ...
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2answers
5k views

Regression Model and Spatial Autocorrelation

I have used OLS and GWR for validating the dependencies between two distinct database. The Residual Square for GWR is 0.82 and thereby making it the right regression model to be used for determining ...