
01-20-2019, 04:18 PM
|
 |
NTU
|
|
Join Date: Aug 2009
Location: Taipei, Taiwan
Posts: 601
|
|
Re: What is the definition of expectation with respect to data set
Quote:
Originally Posted by Fromdusktilldawn
Thank you for the answer.
However, there is still a distinction between a vector, and a set of vectors.
In other words, {1} is not the same as 1.
However, in multiple locations in the textbook, the dataset is represented as a set. For example, at the bottom of page 8.
My question is, is the dataset a vector consisting of pairs, or a set of pairs?
In other words, the distinction between [(1,2), (3,4)]^T versus {(1,2), (3,4)}. I don't really understand the notation D = (x_1, y_1), (x_2, y_2)...(x_N,y_N) because as it is written it is neither a vector nor a set.
I apologize in advance if I am being too rigorous and nitpicky
|
The data set is a set of pairs in this book. While the set is by definition not ordered, the data set is more often "ordered by index"---and thus conveniently represented by a (pair of) matrix (like what we did in Chapter 3).
Hope this helps.
__________________
When one teaches, two learn.
|