Re: [R] Determining model parameters

2008-08-08 Thread Ben Bolker
-BEGIN PGP SIGNED MESSAGE- Hash: SHA1 [EMAIL PROTECTED] wrote: | I am trying to fit a set of data to a Weibull distribution. Because the implementation requires that I put the data in the range of 0 x 1 I have a normailze function: | | normalize - function(x) { | y - (x-min(x)) /

Re: [R] Determining model parameters

2008-08-07 Thread rkevinburton
I am trying to fit a set of data to a Weibull distribution. Because the implementation requires that I put the data in the range of 0 x 1 I have a normailze function: normalize - function(x) { y - (x-min(x)) / (max(x) - min(x)) y = y + 0.5 * (y == 0) -0.5 * (y == 1) return (y)

[R] Determining model parameters

2008-08-03 Thread rkevinburton
This may be a begining question. If so, please bear with me. If I have some data that based on the historgram and other plots it looks like a beta distribution. Is there a function or functions within R to help me determine the model parameters for such a distirbution? Similarily for other

Re: [R] Determining model parameters

2008-08-03 Thread Ben Bolker
rkevinburton at charter.net writes: If I have some data that based on the historgram and other plots it looks like a beta distribution. Is there a function or functions within R to help me determine the model parameters for such a distirbution? library(MASS) ?fitdistr

Re: [R] Determining model parameters

2008-08-03 Thread Ben Bolker
~ The beta distribution only applies to data that are bounded between 0 and 1 (in some cases strictly bounded, i.e. 0x1 not just 0=x=1). ~ As a start, try something like d2 = (Diff-min(Diff)+0.001)/(max(Diff)-min(Diff)+0.002) fitdistr(d2,densfun=beta,start=list(shape1=3,shape2=2)) ~