Questions tagged [moran-index]

Measure of spatial autocorrelation

Filter by
Sorted by
Tagged with
0 votes
0 answers
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 ...
user avatar
-1 votes
0 answers
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....
user avatar
3 votes
1 answer
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 ...
user avatar
  • 33
1 vote
1 answer
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 ...
user avatar
  • 1,797
1 vote
2 answers
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 ...
user avatar
  • 1,797
2 votes
0 answers
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 ...
user avatar
  • 1,797
3 votes
2 answers
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 ...
user avatar
  • 1,797
0 votes
1 answer
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() ...
user avatar
  • 323
0 votes
0 answers
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 ...
user avatar
0 votes
0 answers
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 ...
user avatar
4 votes
1 answer
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-...
user avatar
2 votes
0 answers
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 ...
user avatar
  • 249
1 vote
0 answers
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 ...
user avatar
0 votes
1 answer
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 ...
user avatar
3 votes
1 answer
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 ...
user avatar
  • 2,271
0 votes
0 answers
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 ...
user avatar
  • 11
2 votes
0 answers
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 ...
user avatar
  • 181
3 votes
1 answer
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-...
user avatar
  • 377
0 votes
2 answers
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 ...
user avatar
0 votes
1 answer
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 ...
user avatar
  • 39
0 votes
1 answer
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 ...
user avatar
  • 253
5 votes
1 answer
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?
user avatar
  • 143
0 votes
1 answer
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 ...
user avatar
3 votes
1 answer
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 ...
user avatar
  • 89
2 votes
1 answer
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 ...
user avatar
0 votes
1 answer
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 ...
user avatar
1 vote
1 answer
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 ...
user avatar
1 vote
1 answer
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 ...
user avatar
2 votes
1 answer
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|...
user avatar
  • 165
1 vote
1 answer
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, ...
user avatar
  • 481
1 vote
1 answer
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 ...
user avatar
  • 175
-1 votes
1 answer
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 ...
user avatar
  • 91
2 votes
0 answers
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 ...
user avatar
2 votes
2 answers
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 ...
user avatar
  • 277
2 votes
1 answer
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 ...
user avatar
0 votes
2 answers
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 ...
user avatar
4 votes
1 answer
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 ...
user avatar
  • 573
0 votes
1 answer
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?
user avatar
  • 35
1 vote
0 answers
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 ...
user avatar
  • 69
3 votes
0 answers
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 ...
user avatar
  • 1,333
2 votes
1 answer
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 ...
user avatar
  • 171
1 vote
1 answer
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 ...
user avatar
  • 843
15 votes
2 answers
6k 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 ...
user avatar
  • 4,265