theorem

Documentation

Overview

Package theorem is an Bayes' theorem implementation.

Index

• func Bayes(priorPtoB, priorPfromAtoB, priorPNotFromAtoB float64) float64

Examples

• Bayes

Functions

func Bayes

func Bayes(priorPtoB, priorPfromAtoB, priorPNotFromAtoB float64) float64

Bayes returns the probability from the given probability based on Bayes' theorem. In other words, it returns the probability of event B occurring when event A occurred.

• priorPtoB is the prior probability occurrence of event B.
• priorPfromAtoB is the prior probability occurrence of event B when previous event A occurred.
• priorPNotFromAtoB is the prior probability that did not occur event B when previous event A occurred.

Example

package main

import (
	"fmt"

	"github.com/KEINOS/go-bayes/pkg/theorem"
)

func main() {
	// Validation of figures
	// Bayes' theorem
	x := 0.3 * 0.4
	y := x + (1.-0.3)*0.5
	expect := x / y //nolint: ifshort // not using short syntax for readability

	// Prior probability to be B.
	PriorProbToB := 0.3
	// Prior probability to be B if the previous was A.
	PriorProbFromAtoB := 0.4
	// Prior probability not to be B if the previous was A.
	PriorProbNotFromAtoB := 0.5

	actual := theorem.Bayes(PriorProbToB, PriorProbFromAtoB, PriorProbNotFromAtoB)

	if expect == actual {
		fmt.Println("OK")
	}

}

Output:

OK