[R-sig-Geo] basic question

[Ashton Shortridge]

Hi Kátia,

this isn't really a spatial question, but here goes with an answer.

Your solution lies in the help documentation for the sample function. At the 
command prompt, type ?sample   for one way to access help. The basic 
command is this:
sample(x, size, replace = FALSE, prob = NULL)

For R beginners and experts alike, often the most helpful part of help is the 
usage section at the bottom of the documentation. You can run the example 
usage code at the command prompt to see what happens.

In your specific question, you can see that you simply do this:
x <- 1:12
sample(x, 5, replace=TRUE)  # probably duplicates; what you want, right?

so for your example, this should work:
h<-dados[sample(1:357,20, replace=TRUE),]


Yours,

Ashton

On 05/22/13, Kátia Emidio, wrote:
> does anyone could help me with do a sample from dataframe, using
> replacement equal True? I am a very beginner at R.
> 
>  without replacement, my script works...
> 
> h<-dados[sample(1:357,20),]# this is ok. from 357 rows, I take 20 ones,
> with all columms... How puts the replace=T ?
> thanks
> katia


-----
Ashton Shortridge
Associate Professor			ashton at msu.edu
Dept of Geography			http://www.msu.edu/~ashton
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