Help me to make best fit with error

  • Thread starter Thread starter shad0w2000
  • Start date Start date
  • Tags Tags
    Error Fit
shad0w2000
Messages
5
Reaction score
0
Hi,

I have a set of datapoints (x_i,y_i) and I am going to make a best fit to y = c*Exp(a/x)

Making the fit isn't the problem (Mathematica, etc. can handle this), but what I need is the error on a.

What I have done so far is something like this:

P(c,a | {x_i,y_i} ) = k * P( {x_i,y_i} | c,a ) using Bayes.

And then

P({(x_1,y_1),(x_2,y_2),...}|c,a) = product of ( P(x_i,y_i | c,a) ) for all i's.

which is proportional with

product of ( P(y_i | x_i, c,a) )



But I can't get any further than this :)

Can anyone help me with this ?

Thanks in advance
 
Physics news on Phys.org
How are you defining the error on 'a'? Totally missing what you mean!
 
y = c*Exp(a/x)
Log y = Log c + a (1/x)
v = d + a z where v = Log y, d = Log c and z = 1/x.

Now you have a linear regression that you can compute with any type of software that will print out the standard errors for the regression parameters d and a. For example, Excel. Or use the Regress function in Math'ca (after you enter Needs["LinearRegression`"]).
 
Last edited:
Hi all, I've been a roulette player for more than 10 years (although I took time off here and there) and it's only now that I'm trying to understand the physics of the game. Basically my strategy in roulette is to divide the wheel roughly into two halves (let's call them A and B). My theory is that in roulette there will invariably be variance. In other words, if A comes up 5 times in a row, B will be due to come up soon. However I have been proven wrong many times, and I have seen some...
Thread 'Detail of Diagonalization Lemma'
The following is more or less taken from page 6 of C. Smorynski's "Self-Reference and Modal Logic". (Springer, 1985) (I couldn't get raised brackets to indicate codification (Gödel numbering), so I use a box. The overline is assigning a name. The detail I would like clarification on is in the second step in the last line, where we have an m-overlined, and we substitute the expression for m. Are we saying that the name of a coded term is the same as the coded term? Thanks in advance.
Back
Top