[R] Help with function "fitdistr" in "MASS"

[Peter Ehlers]

Saji Ren wrote:
> Thank you,man. the problem solved.
> Plus. when I got the parameters of the data.
> And I used the "truehist(mydata)" to get a histogram of the data,
> How can I draw a line of the distribution of the estimated parameters in the
> histogram plot?
> 
> for example:
>> fitdistr(na.exclude(mydata),"normal")
>      mean         sd    
>    4.052594   75.620350 
>  ( 1.420743) ( 1.004617)
>> truehist(mydata)
> 
> After that, I got the histogram of mydata.
> And I want plot a extra line of the density of a normal distribution of
> mean=4.052594 and sd=75.620350 in the histogram plot?
add this:

curve(dnorm(x, mean=4.052594, sd=75.620350), add=TRUE)

  -Peter Ehlers

> 
> thank you 
> 
> 
> 
> Bernardo Rangel tura wrote:
>> On Sat, 2010-01-02 at 23:20 -0800, Saji Ren wrote:
>>> Hi, R users:
>>>
>>> I want to fit my data into a normal distribution by using the command
>>> "fitdistr" in "MASS".
>>> I changed my data class from "ts" to "numeric" by
>>>
>>>> class(mydata)="numeric"
>>> but after using "fitdistr", I got the result below
>>>
>>>> fitdistr(mydata,"normal")
>>>   mean    sd 
>>>   NA     NA  
>>>  (NA)   (NA) 
>>>
>>> the help doc of "fitdistr" does not mention anything about that, thus I
>>> need
>>> your help.
>>>
>>> Thank you in advanced,
>>> Saji from Shanghai
>> Hi Sajj,
>>
>> You hava NA in your data
>>
>> try: fitdistr(na.exclude(mydata),"normal")
>>
>> -- 
>> Bernardo Rangel Tura, M.D,MPH,Ph.D
>> National Institute of Cardiology
>> Brazil
>>
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>> https://stat.ethz.ch/mailman/listinfo/r-help
>> PLEASE do read the posting guide
>> http://www.R-project.org/posting-guide.html
>> and provide commented, minimal, self-contained, reproducible code.
>>
>>
> 

-- 
Peter Ehlers
University of Calgary
403.202.3921