How to find uncertainties in the coefficients of polyfit

How to find uncertainties in the coefficients of polyfit

Answer 1

[aneps]

Try this:

 [P,S,MU] = polyfit(x,y,N)

 [y,DELTA] = polyval(P,x,S,MU) % this will give you the error

Refer: http://www.mathworks.com/help/matlab/ref/polyfit.html http://www.mathworks.com/help/matlab/ref/polyval.html

[Chris Martin]

actually i need the uncertainty associated with the determination of coefficients, ie i need the uncertainty associated with m, of y=mx+c

[Riccardo]

I too am looking for an answer to this!

Answer 2

[Star Strider]

An earlier version of my polyparci function already existed when this question originally posted. It calculates the confidence intervals on each parameter.

I just uploaded a significant upgrade to the original version that now additionally returns the probabilities for each parameter.