Thread: Breaking Point View Single Post
#5
04-15-2016, 09:02 PM
 ntvy95 Member Join Date: Jan 2016 Posts: 37
Re: Breaking Point

Quote:
 Originally Posted by lfdid Definition 2.3 on p. 45 of the LFD book says that "if NO data set of size k can be shattered by H, then k is the break point for H." My understanding is that it should read: "if there is a data set of size k such that it can NOT be shattered by H, then k is the break point for H". Is this correct? Many thanks!
I don't think so. For the example of Positive rays (Page 43-44), the book also says:

Quote:
 Notice that if we picked N points where some of the points coincided (which is allowed), we will get less than N + 1 dichotomies. This does not affect the value of mH(N) since it is defined based on the maximum number of dichotomies.
In the Positive intervals example, we have derived:

We observe that not all the value of k gets , indeed:

This means that for some (not all) data set of size , the hypothesis set H is able to shatter (in other words, be able to generate dichotomies). However, for any data set of size , there is no way that the hypothesis set H is able to generate dichotomies.

For example, if , the hypothesis set H is only able to generate 7 dichotomies (while ). However, even when , if the two points coincide (both have the same value of x), there is no way for H to generate dichotomies on those points.