[R] named list 'start' in fitdistr

[vincent.stoliaroff@sgcib.com]

Hi R lovers!

I'd like to know how to use the parameter 'start' in the function
fitdistr()
obviously I have to provide the initial value of the parameter to optimize
except in the case of a certain set of given distribution


Indeed according to the help file for fitdistr
"     For the following named distributions, reasonable starting values
     will be computed if `start' is omitted or only partially
     specified: `cauchy', `gamma', `logistic', `negative binomial' (R
     only, parametrized by `mu' and `size'), `t', `uniform', `weibull'.   "


However I cannot fit an univariate distribution named 'test'

I get this:

>fitdistr(test,"lognormal")
Error in fitdistr(test, "lognormal") : `start' must be a named list

> fitdistr(test,"lognormal",start$meanlog=0,start$sdlog=1)
Error: syntax error

How I am supposed to type a value for start depending on the distribution
on which I am fitting my set

thanks




******************************************************************
The sender's email address has changed to 
firstname.lastname@ sgcib.com. You may want to update your 
personal address book. Please see http://www.sgcib.com for more 
information.
                               **
This message and any attachments (the "message") are confide...{{dropped}}