November 2012
Intermediate to advanced
794 pages
22h 9m
English
book
Probability, Random Variables, and Random Processes: Theory and Signal Processing Applications
by John J. Shynk
Content preview from Probability, Random Variables, and Random Processes: Theory and Signal Processing ApplicationsBecome an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month,
O’Reilly covers everything we've got, with content to help us build a world-class technology community, upgrade the capabilities and competencies of our teams, and improve overall team performance as well as their engagement.I wanted to learn C and C++, but it didn't click for me until I picked up an O'Reilly book. When I went on the O’Reilly platform, I was astonished to find all the books there, plus live events and sandboxes so you could play around with the technology.I’ve been on the O’Reilly platform for more than eight years. I use a couple of learning platforms, but I'm on O'Reilly more than anybody else. When you're there, you start learning. I'm never disappointed.I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.
9.4 MINIMAL SUFFICIENT STATISTIC
In order to estimate θ, we can generally use any sufficient statistic, but it is more practical to use the sufficient statistic with the lowest dimension. Since all statistics are functions of the samples, a minimal sufficient statistic is defined as follows.
Definition: Minimal Sufficient Statistic Sufficient statistic T for parameter θ is minimal if it can be expressed as a function of every other sufficient statistic for θ.
Since a function of the N samples 
cannot increase the dimension (a function by definition has a unique value for each value of its argument), it is clear that a minimal sufficient statistic must have the lowest dimension possible of all sufficient statistics. If the minimal sufficient statistic is related to another sufficient statistic via a one-to-one function, then both are minimal: they are equivalent. It is important to note that the definition above has two requirements: (i) T must be sufficient and (ii) T is a function of all other sufficient statistics for θ.
Example 9.9. For the uniform pdf 
, the following single statistic is not minimal sufficient:
Even though T is a function of the sufficient statistics {X
Become an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month,
and much more.
Read now
Unlock full access
More than 5,000 organizations count on O’Reilly
O’Reilly covers everything we've got, with content to help us build a world-class technology community, upgrade the capabilities and competencies of our teams, and improve overall team performance as well as their engagement.Julian F.
I wanted to learn C and C++, but it didn't click for me until I picked up an O'Reilly book. When I went on the O’Reilly platform, I was astonished to find all the books there, plus live events and sandboxes so you could play around with the technology.Addison B.
I’ve been on the O’Reilly platform for more than eight years. I use a couple of learning platforms, but I'm on O'Reilly more than anybody else. When you're there, you start learning. I'm never disappointed.Amir M.
I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.