View Single Post
  #10   Spotlight this post!  
Unread 13-03-2012, 11:46
Nathan Streeter's Avatar
Nathan Streeter Nathan Streeter is offline
FIRST Fan(atic)
FRC #1519 (Mechanical MAYHEM)
Team Role: Mentor
 
Join Date: Feb 2008
Rookie Year: 2006
Location: Merrimack, NH
Posts: 676
Nathan Streeter has a reputation beyond reputeNathan Streeter has a reputation beyond reputeNathan Streeter has a reputation beyond reputeNathan Streeter has a reputation beyond reputeNathan Streeter has a reputation beyond reputeNathan Streeter has a reputation beyond reputeNathan Streeter has a reputation beyond reputeNathan Streeter has a reputation beyond reputeNathan Streeter has a reputation beyond reputeNathan Streeter has a reputation beyond reputeNathan Streeter has a reputation beyond repute
Re: Week--2 All regionals OPR

Quote:
Originally Posted by Ether View Post
Mathematically speaking, it's an exact (and unique) solution to a least-squares problem.

Good description, but replace the phrase "match scores" with whatever alliance metric is being analyzed.

No iteration is necessary since the set of simultaneous equations is linear in the parameters. It can be solved directly without iteration by forming the normal equations for the system and then using matrix methods (this is how all the solvers I have seen here on CD do it). It can also be solved by using matrix methods directly on the design matrix without forming the normal equations. This latter method is numerically more stable and provides greater precision, but it is more computation-intensive and is overkill for this application.

For those interested in the math, a short explanation of the matrix math required to solve the normal equations is given here.


Thanks for clarifying where I was misleading - I know my knowledge of OPR calculations is somewhat lacking... I was hoping I could clear up some confusion and initiate someone like you, Bongle, or Ed Law clearing up where I was confused.

Thanks for all you guys bring to those of us who use and appreciate the stats but lack the software and statistical experience to generate them.


Nathan
__________________
"If you want to build a ship, don't drum up men to gather wood, divide the work, or give orders. Instead, teach them to yearn for the vast and endless sea." - Antoine de Saint-Exupery
"The fight is won or lost far away from witnesses - behind the lines, in the gym, and out there on the road, long before I dance under those lights." - Muhammad Ali
"Simplicity is the ultimate sophistication." - Leonardo da Vinci


Student: 2006-2010 (#1519)
Mentor: 2011-Present (#1519)


Reply With Quote