Open main menu
Home
Random
Recent changes
Special pages
Community portal
Preferences
About Wikipedia
Disclaimers
Incubator escapee wiki
Search
User menu
Talk
Dark mode
Contributions
Create account
Log in
Editing
Conditional independence
(section)
Warning:
You are not logged in. Your IP address will be publicly visible if you make any edits. If you
log in
or
create an account
, your edits will be attributed to your username, along with other benefits.
Anti-spam check. Do
not
fill this in!
==Conditional independence of random vectors== Two [[random vector]]s <math>\mathbf{X}=(X_1,\ldots,X_l)^{\mathrm T}</math> and <math>\mathbf{Y}=(Y_1,\ldots,Y_m)^{\mathrm T}</math> are conditionally independent given a third random vector <math>\mathbf{Z}=(Z_1,\ldots,Z_n)^{\mathrm T}</math> if and only if they are independent in their conditional cumulative distribution given <math>\mathbf{Z}</math>. Formally: {{Equation box 1 |indent = |title= |equation = {{NumBlk||<math>(\mathbf{X} \perp\!\!\!\perp \mathbf{Y}) \mid \mathbf{Z} \quad \iff \quad F_{\mathbf{X},\mathbf{Y}|\mathbf{Z}=\mathbf{z}}(\mathbf{x},\mathbf{y}) = F_{\mathbf{X}\,\mid\,\mathbf{Z}\,=\,\mathbf{z}}(\mathbf{x}) \cdot F_{\mathbf{Y}\,\mid\,\mathbf{Z}\,=\,\mathbf{z}}(\mathbf{y}) \quad \text{for all } \mathbf{x},\mathbf{y},\mathbf{z}</math>|{{EquationRef|Eq.3}}}} |cellpadding= 6 |border |border colour = #0073CF |background colour=#F5FFFA}} where <math>\mathbf{x}=(x_1,\ldots,x_l)^{\mathrm T}</math>, <math>\mathbf{y}=(y_1,\ldots,y_m)^{\mathrm T}</math> and <math>\mathbf{z}=(z_1,\ldots,z_n)^{\mathrm T}</math> and the conditional cumulative distributions are defined as follows. : <math>\begin{align} F_{\mathbf{X},\mathbf{Y}\,\mid\,\mathbf{Z}\,=\,\mathbf{z}}(\mathbf{x},\mathbf{y}) &= \Pr(X_1 \leq x_1,\ldots,X_l \leq x_l, Y_1 \leq y_1,\ldots,Y_m \leq y_m \mid Z_1=z_1,\ldots,Z_n=z_n) \\[6pt] F_{\mathbf{X}\,\mid\,\mathbf{Z}\,=\,\mathbf{z}}(\mathbf{x}) &= \Pr(X_1 \leq x_1,\ldots,X_l \leq x_l \mid Z_1=z_1,\ldots,Z_n=z_n) \\[6pt] F_{\mathbf{Y}\,\mid\,\mathbf{Z}\,=\,\mathbf{z}}(\mathbf{y}) &= \Pr(Y_1 \leq y_1,\ldots,Y_m \leq y_m \mid Z_1=z_1,\ldots,Z_n=z_n) \end{align}</math>
Edit summary
(Briefly describe your changes)
By publishing changes, you agree to the
Terms of Use
, and you irrevocably agree to release your contribution under the
CC BY-SA 4.0 License
and the
GFDL
. You agree that a hyperlink or URL is sufficient attribution under the Creative Commons license.
Cancel
Editing help
(opens in new window)