How can i get the mean of the function using symbolic maths in MATLAB
7 vues (au cours des 30 derniers jours)
Afficher commentaires plus anciens
i am interested to find the mean of the distribution but I am unable to get it.Could anybody help me to figure out where I am doing the mistake?
f=@(a,b,x)1./(x*b*sqrt(2*pi)).*exp(-((log(x)-a)./(sqrt(2)*b)).^2)
I am interested to find E(X) in symbolic form.
i know from the existing literature E(X)=exp(a+b^2/2) but i am not getting this answer. I am using the the function int(f,x,[0,inf]) by assuming that a is real value constant, b is greater and equal to zero.
Thanks
0 commentaires
Réponses (1)
John D'Errico
le 26 Avr 2017
Note that if P(x) is a PDF on the domain [0,inf], then the expected value of the corresponding random variable is gotten from
int(P(x)*x,x,[0,inf])
To start with, it looks like you forgot to multiply by x.
A quick look at the PDF shows that you seem to be looking for the expected value of a lognormal distribution.
Voir également
Catégories
En savoir plus sur Assumptions dans Help Center et File Exchange
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!