bayes_theorem.cpp File Reference

Bayes' theorem More...

#include <iostream>

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Functions
double	bayes_AgivenB (double BgivenA, double A, double B)
double	bayes_BgivenA (double AgivenB, double A, double B)
int	main ()

Detailed Description

Bayes' theorem

Bayes' theorem allows one to find \(P(A|B)\) given \(P(B|A)\) or \(P(B|A)\) given \(P(A|B)\) and \(P(A)\) and \(P(B)\).
Note that \(P(A|B)\) is read 'The probability of A given that the event B has occured'.

Function Documentation

bayes_AgivenB()

double bayes_AgivenB	(	double	BgivenA,
		double	A,
		double	B )

returns P(A|B)

                                                         {
    return (BgivenA * A) / B;
}

bayes_BgivenA()

double bayes_BgivenA	(	double	AgivenB,
		double	A,
		double	B )

returns P(B|A)

                                                         {
    return (AgivenB * B) / A;
}

main()

int main

(

void

)

Main function

           {
    double A = 0.01;
    double B = 0.1;
    double BgivenA = 0.9;
    double AgivenB = bayes_AgivenB(BgivenA, A, B);
    std::cout << "A given B = " << AgivenB << std::endl;
    std::cout << "B given A = " << bayes_BgivenA(AgivenB, A, B) << std::endl;
    return 0;
}

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