A question about conditional mean

  • Context: Graduate 
  • Thread starter Thread starter lequan
  • Start date Start date
  • Tags Tags
    Conditional Mean
Click For Summary
SUMMARY

The discussion centers on calculating the conditional expectation E(X|X_{sub}=A) for a multivariate normal distribution X ~ N(mu, Sigma), where mu is an n by 1 vector and Sigma is an n by n covariance matrix. The correct formula for this calculation is E(Y|X=x) = mu_Y + Sigma_{YX} Sigma^{-1}_X (x - mu_x). This formula is well-established in statistical literature and is crucial for understanding conditional distributions in multivariate statistics.

PREREQUISITES
  • Understanding of multivariate normal distribution
  • Familiarity with conditional expectation
  • Knowledge of covariance matrices
  • Basic statistics concepts from standard textbooks
NEXT STEPS
  • Study the properties of multivariate normal distributions
  • Learn about conditional distributions in statistics
  • Explore the derivation of the conditional expectation formula
  • Review statistical textbooks that cover multivariate analysis
USEFUL FOR

Statisticians, data scientists, and students studying multivariate statistics who need to understand conditional expectations and their applications in statistical modeling.

lequan
Messages
6
Reaction score
0
X (n by 1) follows a multivariate normal distribution, i.e.,

X ~ N(mu, Sigma). mu is n by 1, Sigma is n by n.

What is

E(X|X_{sub}=A)?

where the index 'sub' (m by 1) is a subset of {1,2,..,n}, A is m by 1, 1 <= m < n.
 
Physics news on Phys.org
Thanks a lot for the reference! This is the right answer. Actually, this is about the conditional distribution of multivariate normal variables, and well known in any standard textbook of basic statistics. However, I failed to realize this early. :(
 

Similar threads

  • · Replies 2 ·
Replies
2
Views
2K
Replies
1
Views
4K
  • · Replies 42 ·
2
Replies
42
Views
6K
Replies
5
Views
6K
  • · Replies 1 ·
Replies
1
Views
3K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 12 ·
Replies
12
Views
5K
  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 27 ·
Replies
27
Views
3K
Replies
2
Views
2K