[R] Bootstrapping in R

[Daniel Nordlund]

On 9/30/2016 6:44 PM, Bryan Mac wrote:
> Hi,
>
> I have read the help page and it was helpful but, I am having concerns because each time I run this code I get the same value.
> I expected that each time I run the code, I will get different values due to random sampling.
>
> How do I get this randomization? The values shouldn’t be the same each time the code is run, correct?
>
>
> result <- boot(n_data, statistic = DataSummary, R = 100).
>
>
> Best,
>
> Bryan Mac
> bryanmac.24 at gmail.com
>
>
>
>> On Sep 29, 2016, at 12:16 PM, ruipbarradas at sapo.pt wrote:
>>
>> Hello,
>>
>> Read the help page ?boot::boot.
>> For instance, try the following.
>>
>>
>> library(boot)
>>
>> x <- rnorm(100)
>> stat <- function(x, f) mean(x[f])
>> boot(x, stat, R = 100)
>>
>> Hope this helps,
>>
>> Rui Barradas
>>
>>
>>
>> Citando bryan.mac24 <bryan.mac24 at gmail.com>:
>>
>>> Hi all,
>>> I am wondering how to conduct bootstrapping in R. I need bootstrap 100 times. The trick I need to figure out is how to do get a random sample of 100 out of the total number of case.
>>> Best,
>>> BM
>>> 	[[alternative HTML version deleted]]
>>>
>>> ______________________________________________
>>> R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see
>>> 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.
>>
>>
>>
>
>
> 	[[alternative HTML version deleted]]
>
> ______________________________________________
> R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see
> 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.
>

Bryan,

You haven't told us anything about the structure of your data, or the 
definition of the DataSummary function.  We are left to guess what you 
are doing.  The posting guide calls for a reproducible example.  At a 
minimum give us some sample data (myabe use dput()), the definition of 
DataSummary, the code you use to set up and call the boot() funtion, and 
examples of your output that shows you "getting the same answer."

Someone may then be able to do more than guess at what the problem is.

Dan

-- 
Daniel Nordlund
Port Townsend, WA  USA