Hi,
If I understand you correctly, you want a function that lets you sample,
without replacement, from a data frame that is subsetted by a second
variable? Your question is a bit unclear, so this may be not what you want.
If it is, however, this should work:
# function that doesn't force you to always have the same column titles
myfunc = function(my_df,n,var1='idf',var2='casod',var2_subset = 2){
data_of_interest = my_df[my_df[,var2] %in% var2_subset,]
result = sample(my_df[,var1],n,replace=FALSE)
}
#test data
my_df = data.frame(idf=rnorm(100),casod=sample(c(1,2,3),100,replace=TRUE))
# here, it will return 10 samples from the idf rows where casod == 2
x = myfunc(my_df,10,'idf','casod',2)
Jeremy
On Fri, Jun 6, 2014 at 8:39 AM, Rodrigues <[email protected]> wrote:
> Dear R users,
>
>
> Iâm trying to build a function to select random samples idfâs from a
> database.
> So, my data frame had 2 columns and 575 rows. Follow bellow an example of
> my
> database
> Idf1 casod
> 12 1
> 14 1
> 15 1
> 16 1
> 17 3
> 18 3
> 19 3
> 21 3
> 25 1
> 24 1
> 26 1
> 28 1
> 29 3
> 32 3
> 33 3
> 35 1
> 36 3
> 37 1
> 48 3
>
> So my function is
>
> blinding=function(sample){
> sort=sample(idf1,10,replace=F)
> return(sort2)
> }
>
> It is pretty simple and I would like to add one more step in my choice. I
> would like to link my choice to casod stats. Thus if casod==3 sample would
> be random idfs could not be an idf with casod=1. Does someone can help me?
>
>
>
>
> --
> View this message in context:
> http://r-sig-ecology.471788.n2.nabble.com/Help-with-a-function-tp7578931.html
> Sent from the r-sig-ecology mailing list archive at Nabble.com.
>
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--
*___________________________________________________________________________Jeremy
M. Chacon, Ph.D.*
*Post-Doctoral Associate, Gardner Lab*
*University of Minnesota*
*Genetics, Cell Biology, and Development*
*6-160 Jackson Hall*
*321 Church St. SE*
*Minneapolis, MN 55455*
*USA*
*[email protected] <[email protected]>*
*Lab telephone: **612-626-6906*
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