To LUGNET HomepageTo LUGNET News HomepageTo LUGNET Guide Homepage
 Help on Searching
 
Post new message to lugnet.off-topic.geekOpen lugnet.off-topic.geek in your NNTP NewsreaderTo LUGNET News Traffic PageSign In (Members)
 Off-Topic / Geek / 4244
4243  |  4245
Subject: 
Re: On a scale of 0 to 10?
Newsgroups: 
lugnet.off-topic.geek
Date: 
Wed, 26 Mar 2003 18:18:55 GMT
Viewed: 
340 times
  
In lugnet.off-topic.geek, David Eaton writes:
In lugnet.off-topic.geek, Adrian Drake writes:
In lugnet.off-topic.geek, David Eaton writes:
I've got a function that represents a quality rating, based on 2 parameters,
which are on a scale of 0 to 1:

(d-k)*k => quality (q)

*snip*

Thought about that... If necessary I guess, but I'm pretty sure there's a
way to do it. I think what I need is:

s = Ae^(q + B) + C

And at the moment, I've solved:

C = -Ae^(B - 1)
A = 10 / (e^(B + .25) - e^(B - 1))

And I'm scratching my head like crazy to solve for B:

e^(B + .25) + e^(B - 1) = 2e^B

It's been too long since algebra! Anyone know how to solve for B here?

DaveE


summed exponents like that can be re-written in this way:

e^B * e^.25 + e^B * e^-1 = 2e^B

(e^.25 + e^-1) * e^B = 2e^B

Uh oh.  Divide both sides by e^B and we've got

(e^.25 + e^-1) = 2

1.652 = 2

Which ain't right.  I think your math is wrong somewhere.

Adrian



Message has 1 Reply:
  Re: On a scale of 0 to 10?
 
(...) Oh yeah! (...) Oh... yeah. (...) Hm. Double checked the math-- it appears solid [1], which would mean that there's no viable solution for: s = Ae^(q + B) + C for coordinates (-1,0), (0,5), (0.25,10). Darn. Hm. I guess that also means that any (...) (22 years ago, 26-Mar-03, to lugnet.off-topic.geek)

Message is in Reply To:
  Re: On a scale of 0 to 10?
 
(...) Thought about that... If necessary I guess, but I'm pretty sure there's a way to do it. I think what I need is: s = Ae^(q + B) + C And at the moment, I've solved: C = -Ae^(B - 1) A = 10 / (e^(B + .25) - e^(B - 1)) And I'm scratching my head (...) (22 years ago, 26-Mar-03, to lugnet.off-topic.geek)

8 Messages in This Thread:

Entire Thread on One Page:
Nested:  All | Brief | Compact | Dots
Linear:  All | Brief | Compact

This Message and its Replies on One Page:
Nested:  All | Brief | Compact | Dots
Linear:  All | Brief | Compact
    

Custom Search

©2005 LUGNET. All rights reserved. - hosted by steinbruch.info GbR