Mathematics · Statistics

Moran Spatial Autocorrelation Index Calculator

Calculate moran i from normalized weighted cross-deviation numerator and squared-deviation denominator.

Runs locally
Your numbers

Inputs and results stay in this browser. Change one value at a time to explore the relationship.

Your inputCalculatedPassed forward in chains
Moran I0.75

Calculation steps

  1. Use c=a/b with normalized weighted cross-deviation numerator=18 and squared-deviation denominator=24.
  2. Moran I=0.75.

Understand Moran Spatial Autocorrelation Index

One idea, three depths

Choose how deeply to explain Moran Spatial Autocorrelation Index

Moran Spatial Autocorrelation Index: Calculate moran i from normalized weighted cross-deviation numerator and squared-deviation denominator.

Age 5Explain it to a 5-year-oldStart with a picture

Imagine using Moran Spatial Autocorrelation Index to answer this question: calculate moran i from normalized weighted cross-deviation numerator and squared-deviation denominator? Enter normalized weighted cross-deviation numerator and squared-deviation denominator; the calculator shows Moran I. For example: normalized weighted cross-deviation numerator=18 and squared-deviation denominator=24 produce Moran I=0.75. The answer tells you Moran I.

Age 15Explain it to a 15-year-oldConnect it to the formula

Moran's I is a normalized weighted spatial cross-product divided by total squared deviation. This page evaluates the relationship directly. The rule is c=a/b. Its input values are normalized weighted cross-deviation numerator, squared-deviation denominator, and the main result is Moran I. For example: normalized weighted cross-deviation numerator=18 and squared-deviation denominator=24 produce Moran I=0.75.

CollegeExplain it at college levelState the model precisely

This calculator evaluates the stated moran spatial autocorrelation index relation over the valid real-number domain stated below. The implemented relation is c=a/b, evaluated from normalized weighted cross-deviation numerator, squared-deviation denominator to produce Moran I. Moran's I is a normalized weighted spatial cross-product divided by total squared deviation. This page evaluates the relationship directly. The numerator must already include the observation-count-to-weight-sum normalization for the chosen weights matrix.

Inputs and valid domain

  • normalized weighted cross-deviation numerator must be a finite real number.
  • squared-deviation denominator must be a finite real number.

Important boundary: The numerator must already include the observation-count-to-weight-sum normalization for the chosen weights matrix.

The formula

c=a/b

How the calculator works through it

It substitutes normalized weighted cross-deviation numerator, squared-deviation denominator into the formula and exposes every numerical step above. The main output is Moran I.

Read the result correctly

The Moran I is the direct answer to “calculate moran i from normalized weighted cross-deviation numerator and squared-deviation denominator.” Read it with the units shown beside the inputs; a sign, angle, percentage or rate changes what the number means.

A worked check

normalized weighted cross-deviation numerator=18 and squared-deviation denominator=24 produce Moran I=0.75.

Where this model stops being reliable

The numerator must already include the observation-count-to-weight-sum normalization for the chosen weights matrix.

Learn it by changing one value

Begin with the worked example, then change one value while keeping the others fixed. Compare the new result and calculation steps to identify which part of the formula changed.

Dictionary terms behind this calculator

Before studying the codeWhat you should know firstUse the calculator immediately, or check the foundations before reading the implementation.

These foundations help you understand why Moran Spatial Autocorrelation Index works. They never block the calculator, and “optional” means useful context rather than a hidden requirement.

Hard requirements

  • Reading formulas and substituting values

    Moran Spatial Autocorrelation Index uses c=a/b. You need to recognise what each side represents before substituting the stated inputs or rearranging the relationship.

    Review this foundation about 4 min

Strong support

  • Averages and representative values

    Representative values help you judge what the Moran Spatial Autocorrelation Index inputs summarise and what the result can legitimately describe.

    Review this foundation about 5 min

Optional enrichment

  • Spread and measurement variation

    Variation is not always part of the Moran Spatial Autocorrelation Index formula, but it helps you judge how stable a reported result may be.

    Review this foundation about 6 min
Learn the missing foundationsI already know these — show the code

Mathematics → algorithm → program

Implement this calculation in code

These are direct reference implementations of the calculator's principal relationship and first output. They run locally and include a small known-answer check where the language supports it.

Algorithm

  1. Read normalized weighted cross-deviation numerator, squared-deviation denominator.
  2. Evaluate the principal relationship: c=a/b.
  3. Return Moran I and check the domain conditions described above.
Python
            from math import *

def moran_spatial_autocorrelation_calculator(a, b) -> float:
    return (a / b)

assert abs(moran_spatial_autocorrelation_calculator(18, 24) - 0.75) < 1e-6 * max(1.0, abs(0.75))
          
Current calculator valuesUpdates when you change an input above.
              
            
C
            #include <assert.h>
#include <math.h>

double moran_spatial_autocorrelation_calculator(double a, double b) {
    return (a / b);
}

int main(void) {
    const double expected = 0.75;
    const double actual = moran_spatial_autocorrelation_calculator(18, 24);
    assert(fabs(actual - expected) < 1e-6 * fmax(1.0, fabs(expected)));
}
          
Current calculator valuesUpdates when you change an input above.
              
            
C++
            #include <cassert>
#include <cmath>
#include <numbers>

double moran_spatial_autocorrelation_calculator(double a, double b) {
    return (a / b);
}

int main() {
    constexpr double expected = 0.75;
    const double actual = moran_spatial_autocorrelation_calculator(18, 24);
    assert(std::fabs(actual - expected) < 1e-6 * std::fmax(1.0, std::fabs(expected)));
}
          
Current calculator valuesUpdates when you change an input above.
              
            
Linux x86-64 assembly

x86-64 NASM · System V ABI · Linux · SSE2 with libm where required

            ; double moran_spatial_autocorrelation_calculator(double a, double b)
; Linux x86-64 NASM · System V ABI · first eight doubles in xmm0–xmm7
global moran_spatial_autocorrelation_calculator
section .text

moran_spatial_autocorrelation_calculator:
    push rbp
    mov rbp, rsp
    sub rsp, 32
    movsd [rbp-8], xmm0
    movsd [rbp-16], xmm1
    movsd xmm0, [rbp-8]
    divsd xmm0, [rbp-16]
    movsd [rbp-24], xmm0
    movsd xmm0, [rbp-24]
    leave
    ret
          
Current calculator valuesUpdates when you change an input above.
              
            
MATLAB
            function result = moran_spatial_autocorrelation_calculator(a, b)
    result = (a / b);
end
          
Current calculator valuesUpdates when you change an input above.
              
            
Wolfram Language
            ClearAll[mwCalculate];
mwCalculate[a_, b_] := (a / b);
          
Current calculator valuesUpdates when you change an input above.
              
            

Continue in mathematical software

The downloaded file includes your current inputs and first calculated result. It is created locally.

Floating-point answers can differ slightly by language, compiler and processor. Compare within a suitable tolerance rather than assuming every decimal representation will be identical.

Supporting sourcesAcademic referencesPrimary standards, textbooks and complete citations

Standards, reading and academic references

Use the calculator as the worked interaction, then consult the primary standards and academic textbooks listed below. MW SysArc links to the original sources; the explanation on this page is original and does not reproduce them.

Introductory Statistics 2e

Read the free OpenStax statistics textbook
Cite this book
APA 7
Illowsky, B., & Dean, S. (2023). Introductory statistics 2e. OpenStax. https://openstax.org/books/introductory-statistics-2e/pages/1-introduction
MLA 9
Illowsky, Barbara, and Susan Dean. Introductory Statistics 2e. OpenStax, 2023, https://openstax.org/books/introductory-statistics-2e/pages/1-introduction.
Chicago author-date
Illowsky, Barbara, and Susan Dean. 2023. Introductory Statistics 2e. Houston, TX: OpenStax. https://openstax.org/books/introductory-statistics-2e/pages/1-introduction.

OpenStax entries are free to read online. Follow the licence shown on each linked source before redistributing or adapting its content.

Reuse the page responsiblyCite this pageAPA, MLA, Chicago, Harvard, BibTeX and RIS

These formats cite this calculator page itself. They are separate from the academic references above, which support the mathematical method and terminology.

APA 7

MW SysArc. (2026, July 21). Moran Spatial Autocorrelation Index Calculator. MW SysArc Tools. https://math.mwsysarc.com/statistics/moran-spatial-autocorrelation-calculator

MLA 9

MW SysArc. “Moran Spatial Autocorrelation Index Calculator.” MW SysArc Tools, 21 July 2026, https://math.mwsysarc.com/statistics/moran-spatial-autocorrelation-calculator. Accessed 31 Aug. 2026.

Chicago 17

MW SysArc. “Moran Spatial Autocorrelation Index Calculator.” MW SysArc Tools. Published July 21, 2026. Accessed August 31, 2026. https://math.mwsysarc.com/statistics/moran-spatial-autocorrelation-calculator.

Harvard

MW SysArc (2026) ‘Moran Spatial Autocorrelation Index Calculator’, MW SysArc Tools. Published 21 July 2026. Available at: https://math.mwsysarc.com/statistics/moran-spatial-autocorrelation-calculator (Accessed: 31 August 2026).

BibTeX and RIS records

BibTeX

@misc{mwsysarc_moran_spatial_autocorrelation_calculator_2026,
  author = {{MW SysArc}},
  title = {Moran Spatial Autocorrelation Index Calculator},
  howpublished = {MW SysArc Tools},
  year = {2026},
  url = {https://math.mwsysarc.com/statistics/moran-spatial-autocorrelation-calculator},
  note = {Published July 21, 2026; accessed August 31, 2026}
}

RIS

TY  - ELEC
AU  - MW SysArc
TI  - Moran Spatial Autocorrelation Index Calculator
T2  - MW SysArc Tools
PY  - 2026
DA  - 2026-07-21
Y2  - 2026-08-31
UR  - https://math.mwsysarc.com/statistics/moran-spatial-autocorrelation-calculator
N1  - Published July 21, 2026
ER  -

Clear answers

Frequently asked questions

What does the Moran Spatial Autocorrelation Index do?

Calculate moran i from normalized weighted cross-deviation numerator and squared-deviation denominator.

How does the Moran Spatial Autocorrelation Index work?

The calculator applies c=a/b. Moran's I is a normalized weighted spatial cross-product divided by total squared deviation. This page evaluates the relationship directly.

What can I learn from the Moran Spatial Autocorrelation Index?

It connects the mathematical rule to your chosen numbers and shows each calculation step. Change one input at a time to see how the result responds.

Does MW SysArc receive or store what I enter?

No. The calculation runs locally in your browser. MW SysArc does not receive or store your calculation inputs.

How should I use the result?

Use the steps to understand the method, then verify important school or professional work using the notation and rounding rules required in your setting.

Last reviewed . Calculations tested .

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