More statistics

Homework giving you a headache? Math gives you a migraine? Can't quite figure out how to do something in photoshop? Never fear, the other members of CAA share their expertise in this forum.

More statistics

Postby Agent Anderson » Sat Sep 09, 2006 11:24 am

Could someone just explain what the colons and arrows mean?

Image

The unfamiliar notation seems to be the hardest part about this class.


EDIT: Also, does someone have a better explanation of an image?
Image
Agent Anderson
 
Posts: 122
Joined: Sun May 07, 2006 1:59 pm

Postby Technomancer » Sat Sep 09, 2006 11:57 am

The term "X:W->R" indicates that X is a random variable over the sample space W. Any actual realization of the variable X is a member of set R (which in this case is the set of real numbers). The notation in the second line is a bit eccentric, and the ':' is more often written as '|', which simply means 'such that.' In other words, read it as 's is an element of W, such that X(s)>2'.

You tend to see this notation a lot when dealing with functions or transformations. The meaning is similar, except that you are not dealing with random variables. In such a case "X:W->R" would read 'The transformation X operates on a member of set W transforming it to a member of set R'

The "image" of a transformation (or random variable) is the same as its range. In other words it is the set of all values that a realization of X may take on.
http://mathworld.wolfram.com/Image.html
The scientific method," Thomas Henry Huxley once wrote, "is nothing but the normal working of the human mind." That is to say, when the mind is working; that is to say further, when it is engaged in corrrecting its mistakes. Taking this point of view, we may conclude that science is not physics, biology, or chemistry—is not even a "subject"—but a moral imperative drawn from a larger narrative whose purpose is to give perspective, balance, and humility to learning.

Neil Postman
(The End of Education)

Anti-intellectualism has been a constant thread winding its way through our political and cultural life, nurtured by the false notion that democracy means that my ignorance is just as good as your knowledge

Isaac Aasimov
User avatar
Technomancer
 
Posts: 2379
Joined: Fri Jun 13, 2003 11:47 am
Location: Tralfamadore

Postby Agent Anderson » Mon Sep 11, 2006 4:42 am

Thanks.
Agent Anderson
 
Posts: 122
Joined: Sun May 07, 2006 1:59 pm


Return to Tutorials

Who is online

Users browsing this forum: No registered users and 23 guests