how to implement E[x] in matlab?

[bee]

matlab expectation

can anyone plz tell me how to implement E[x] in matlab. E[.] is the expectance.
Also tell me what exectly it is?

Waiting....

 

[artsil23]

expectation matlab

you can use the matlab instruction: mean(x).

MEAN Average or mean value.
For vectors, MEAN(X) is the mean value of the elements in X. For
matrices, MEAN(X) is a row vector containing the mean value of
each column. For N-D arrays, MEAN(X) is the mean value of the
elements along the first non-singleton dimension of X.

MEAN(X,DIM) takes the mean along the dimension DIM of X.

Example: If X = [0 1 2
3 4 5]

then mean(X,1) is [1.5 2.5 3.5] and mean(X,2) is [1 ; 4]

 

[amihomo]

ensemble average matlab

Hi

let f(x) be the PDF of the discrete random variable X=(x1, ..., xN) , the the mathematical expectation of x is defined as


E[x]=∑xif(xi)

(where summation is carried out from i=1 to N)

this equation can simply be written as a for loop in Matlab or any other programming language.

regards

 

[chickoos]

matlab e

Hi,

Expectation of X computes the ensemble average of X. This can be computed using function mean(X)

 

[chengtiezheng]

expectation in matlab

actually,

mean() function do the time average!

the definition of E(.) is E[x]=∑xif(xi)! so amihomo is right!!!

we often use time average instead of ensemble average if the random process
is ergodic!!

 

[kastantin]

calculation of expectation using matlab

simply use mean function
as mean(x), if x is 2-dim then the mean function calculat mean for each colum

 

[rpborse]

% i m explaining this taking an example of throwing a dice:

% Code for finding the expectaion of the given experiment:

clc;
clear all;
close all;

p=[1/6 1/6 1/6 1/6 1/6 1/6];
ln=length(p);
samples=[1 2 3 4 5 6];

expec=0;
for i=1:ln

expec=expec+(p(i)*samples(i));
end

disp(['For the outcome of throwing a dice as: ', num2str(samples)]);
disp(['with probabilities: ' num2str(p)]);
disp(['The expected value of throwing a dice is: ', num2str(expec)]);
-------------------
it works, check it out!!!
reply back!!!
rpborse@gmail.com