# Questions tagged [moran-index]

Measure of spatial autocorrelation

43 questions
Filter by
Sorted by
Tagged with
10 views

### Global Moran I for road crash analysis

I am performing Global Moran's I on road crash point data on ArcGIS Pro. I have around 3000 point features. As far as I understand, first I need to find the threshold distance using an incremental ...
16 views

### I m computing queens contiguity PySal weigth but i have problem that w.n!=dataframe dimension [closed]

Im computing the spatial weights in GeoDataFrame but i have a different dimensions between the weights dim and the rows dim... because I want these two dim to be equal!!! w_queen = weights.contiguity....
61 views

### Spatial autocorrelation has p value of 0.0000

I have just conducted a spatial autocorrelation test with data in adjacent polygons, and have a p value of 0.000000. I used inverse distance, with 0 as the threshold distance. I am confused as to why ...
• 33
1 vote
35 views

### Using weight component in Moran I calculation

I'm trying to understand the Moran I calculation, and there is something I don't understand. In this tutorial, Moran I described as the slope value of the correlation between one polygon to the ...
• 1,797
1 vote
99 views

### interpretation of Global Moran I values using pysal

I'm using pysal library (and this specific notebook) to run spatial autocorrelation. I have question regard the MORAN I value that I recieve. As far as I understand, in order to be able to say ...
• 1,797
30 views

### Difference between MORAN I and LISA

i'm trying to define what is the main difference between Moran I and LISA (local indicator of spatial autocorrelation,which is, as far as I understand,local Moran). I know te MORAN I is global and ...
• 1,797
103 views

### pygeoda - LISA for round polygon

I have just started to use pygeoda package and I have tried to calculate LISA . I had originally raster which I polygonized to have polygon for each pixel: I have applied MORAN I and LISA on the ...
• 1,797
85 views

### Statistical significance of Moran I

I would like to estimate the Moran's I coefficient for raster data together with the statistical significance of the spatial autocorrelation obtained. I found that the raster package function Moran() ...
• 323
24 views

### Local Moran’s I vs Getis-Ord Gi* for Cluster/Hotspot Analysis

I was wondering if someone could perhaps help explain the difference between these two methods and when it might be more appropriate to use one vs the other for cluster/hotspot analysis? I understand ...
• 21
89 views

### NA in the summary of a spline correlogram in the package ncf and doubts about distance units

I am a PhD student currently working on some spatial analysis. I work with a free range population of starlings that breed in nest boxes. Our aim is to know if reproductive success (i.e. number of ...
162 views

### If a Moran's I value is close to 1, then why is it necessary to report the p-value?

For instance, if we get a Moran's I value of around 0.6, then we already know based on that Moran's I value that spatial autocorrelation is present. Why is it important to additionally report the p-...
735 views

### PySAL, ValueError: cannot assign slice from input of different size

I want to calculate local moran's I statistics using pysal with Queen contiguity but I'm getting error. import geopandas as gpd from pysal.explore import esda from pysal.lib import ...
• 249
1 vote
54 views

### 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 ...
141 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 ...
127 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 ...
• 2,271
25 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 ...
• 11
33 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 ...
• 181
588 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-...
• 377
237 views

### Computing Moran's I from a ggplot map using R

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 ...
• 53
283 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 ...
• 39
101 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 ...
• 253
6k 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?
• 143
241 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 ...
• 160
465 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 ...
• 89
267 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 ...
• 131
114 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 ...
1 vote
762 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 ...
• 287
1 vote
110 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 ...
1k 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|...
• 165
1 vote
152 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, ...
• 481
1 vote
953 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 ...
• 175
194 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 ...
• 91
574 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 ...
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 ...
• 277
3k 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 ...
• 123
590 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 ...
• 11
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 ...
• 573
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?
• 35
1 vote
476 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 ...
• 69
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 ...
• 1,333
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 ...
• 171
1 vote
800 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 ...
• 843