Mathematics · Probability

Variation of Information conditional entropy H(X|Y) Solver

Rearrange the variation of information relationship and solve for conditional entropy h(x|y).

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
conditional entropy H(X|Y)1.2
Reconstructed variation of information2.1

Calculation steps

  1. Use a=c−b with variation of information=2.1 and conditional entropy H(Y|X)=0.9.
  2. conditional entropy H(X|Y)=1.2000000000000002.
  3. Substitution into c=a+b reconstructs 2.1.

Understand Variation of Information: solve conditional entropy H(X|Y)

One idea, three depths

Choose how deeply to explain Variation of Information: solve conditional entropy H(X|Y)

Variation of Information: solve conditional entropy H(X|Y): Rearrange the variation of information relationship and solve for conditional entropy h(x|y).

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

Imagine using Variation of Information: solve conditional entropy H(X|Y) to answer this question: rearrange the variation of information relationship and solve for conditional entropy h(x|y)? Enter variation of information and conditional entropy H(Y|X); the calculator shows conditional entropy H(X|Y). For example: conditional entropy H(X|Y)=1.2 and conditional entropy H(Y|X)=0.9 produce variation of information=2.1. The answer tells you conditional entropy H(X|Y).

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

Variation of information adds the two directional conditional entropies and defines a metric on clusterings under standard conditions. This page isolates conditional entropy h(x|y) and verifies it in the original relationship. The rule is a=c−b. Its input values are variation of information, conditional entropy H(Y|X), and the main result is conditional entropy H(X|Y). For example: conditional entropy H(X|Y)=1.2 and conditional entropy H(Y|X)=0.9 produce variation of information=2.1.

CollegeExplain it at college levelState the model precisely

This calculator evaluates the stated variation of information: solve conditional entropy h(x|y) relation over the valid real-number domain stated below. The implemented relation is a=c−b, evaluated from variation of information, conditional entropy H(Y|X) to produce conditional entropy H(X|Y). Variation of information adds the two directional conditional entropies and defines a metric on clusterings under standard conditions. This page isolates conditional entropy h(x|y) and verifies it in the original relationship. Use the same logarithm base and empirical probability convention for both terms.

Inputs and valid domain

  • variation of information must be a finite real number.
  • conditional entropy H(Y|X) must be a finite real number.

Important boundary: Use the same logarithm base and empirical probability convention for both terms.

The formula

a=c−b

How the calculator works through it

It substitutes variation of information, conditional entropy H(Y|X) into the formula and exposes every numerical step above. The main output is conditional entropy H(X|Y), accompanied by Reconstructed variation of information.

Read the result correctly

The conditional entropy H(X|Y) is the direct answer to “rearrange the variation of information relationship and solve for conditional entropy h(x|y).” Read it with the units shown beside the inputs; a sign, angle, percentage or rate changes what the number means.

A worked check

conditional entropy H(X|Y)=1.2 and conditional entropy H(Y|X)=0.9 produce variation of information=2.1.

Where this model stops being reliable

Use the same logarithm base and empirical probability convention for both terms.

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 Variation of Information: solve conditional entropy H(X|Y) works. They never block the calculator, and “optional” means useful context rather than a hidden requirement.

Hard requirements

  • Reading formulas and substituting values

    Variation of Information: solve conditional entropy H(X|Y) uses a=c−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

  • Probability as a modelled proportion

    Probability rules are needed to interpret what the Variation of Information: solve conditional entropy H(X|Y) result says about possible outcomes.

    Review this foundation about 5 min

Optional enrichment

  • Ordered arrangements

    Counting ordered arrangements can extend Variation of Information: solve conditional entropy H(X|Y) to more detailed sample spaces and event models.

    Review this foundation about 5 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 variation of information, conditional entropy H(Y|X).
  2. Evaluate the principal relationship: a=c−b.
  3. Return conditional entropy H(X|Y) and check the domain conditions described above.
Python
            from math import *

def variation_of_information_solve_a(c, b) -> float:
    return (c - b)

assert abs(variation_of_information_solve_a(2.1, 0.9) - 1.2000000000000002) < 1e-6 * max(1.0, abs(1.2000000000000002))
          
Current calculator valuesUpdates when you change an input above.
              
            
C
            #include <assert.h>
#include <math.h>

double variation_of_information_solve_a(double c, double b) {
    return (c - b);
}

int main(void) {
    const double expected = 1.2000000000000002;
    const double actual = variation_of_information_solve_a(2.1, 0.9);
    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 variation_of_information_solve_a(double c, double b) {
    return (c - b);
}

int main() {
    constexpr double expected = 1.2000000000000002;
    const double actual = variation_of_information_solve_a(2.1, 0.9);
    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 variation_of_information_solve_a(double c, double b)
; Linux x86-64 NASM · System V ABI · first eight doubles in xmm0–xmm7
global variation_of_information_solve_a
section .text

variation_of_information_solve_a:
    push rbp
    mov rbp, rsp
    sub rsp, 32
    movsd [rbp-8], xmm0
    movsd [rbp-16], xmm1
    movsd xmm0, [rbp-8]
    subsd 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 = variation_of_information_solve_a(c, b)
    result = (c - b);
end
          
Current calculator valuesUpdates when you change an input above.
              
            
Wolfram Language
            ClearAll[mwCalculate];
mwCalculate[c_, b_] := (c - b);
          
Current calculator valuesUpdates when you change an input above.
              
            

Continue in mathematical software

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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). Variation of Information conditional entropy H(X|Y) Solver. MW SysArc Tools. https://math.mwsysarc.com/probability/variation-of-information-conditional-entropy-h-x-y-solver

MLA 9

MW SysArc. “Variation of Information conditional entropy H(X|Y) Solver.” MW SysArc Tools, 21 July 2026, https://math.mwsysarc.com/probability/variation-of-information-conditional-entropy-h-x-y-solver. Accessed 31 Aug. 2026.

Chicago 17

MW SysArc. “Variation of Information conditional entropy H(X|Y) Solver.” MW SysArc Tools. Published July 21, 2026. Accessed August 31, 2026. https://math.mwsysarc.com/probability/variation-of-information-conditional-entropy-h-x-y-solver.

Harvard

MW SysArc (2026) ‘Variation of Information conditional entropy H(X|Y) Solver’, MW SysArc Tools. Published 21 July 2026. Available at: https://math.mwsysarc.com/probability/variation-of-information-conditional-entropy-h-x-y-solver (Accessed: 31 August 2026).

BibTeX and RIS records

BibTeX

@misc{mwsysarc_variation_of_information_solve_a_2026,
  author = {{MW SysArc}},
  title = {Variation of Information conditional entropy H(X|Y) Solver},
  howpublished = {MW SysArc Tools},
  year = {2026},
  url = {https://math.mwsysarc.com/probability/variation-of-information-conditional-entropy-h-x-y-solver},
  note = {Published July 21, 2026; accessed August 31, 2026}
}

RIS

TY  - ELEC
AU  - MW SysArc
TI  - Variation of Information conditional entropy H(X|Y) Solver
T2  - MW SysArc Tools
PY  - 2026
DA  - 2026-07-21
Y2  - 2026-08-31
UR  - https://math.mwsysarc.com/probability/variation-of-information-conditional-entropy-h-x-y-solver
N1  - Published July 21, 2026
ER  -

Clear answers

Frequently asked questions

What does the Variation of Information: solve conditional entropy H(X|Y) do?

Rearrange the variation of information relationship and solve for conditional entropy h(x|y).

How does the Variation of Information: solve conditional entropy H(X|Y) work?

The calculator applies a=c−b. Variation of information adds the two directional conditional entropies and defines a metric on clusterings under standard conditions. This page isolates conditional entropy h(x|y) and verifies it in the original relationship.

What can I learn from the Variation of Information: solve conditional entropy H(X|Y)?

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.

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