[R] New to R

Joe Hughes joe.hughes at earthlink.net
Mon Feb 2 19:16:33 CET 2009


Gabor,

	Shouldn't the replace be TRUE instead of FALSE?  I get this error

Error in sample(6, 28, replace = FALSE) :
   cannot take a sample larger than the population when 'replace =  
FALSE'

when I use FALSE.  I don't get the error when it is TRUE.  Examining  
my mental model of what is going on you can't remove a number from a  
die thus each sample(value of the die) when selected has to be  
replaced.  Or am I missing something?

Thanks,
Joe

On Feb 2, 2009, at 1:00 PM, Gabor Grothendieck wrote:

> Try this:
>
> matrix(sample(dsize, nrolls * ndice, replace = FALSE), nrolls, ndice)
>
> On Mon, Feb 2, 2009 at 12:39 PM, Joe Hughes  
> <joe.hughes at earthlink.net> wrote:
>> Hello All,
>>
>>       A colleague of mine started working with R and out of  
>> curiosity I did
>> some research on the language.  Very nice.  In my opinion this is  
>> one of the
>> best languages I've found for getting tasks I'm interested in  
>> done.  I wrote
>> this simple die roller and was curious to know if it is R enough.
>>
>> ##############################################################################
>> #
>> # Input:
>> #   die_size - 4, 6, 8, 10, 20
>> #   number_of_dice - How many dice to roll
>> #   number_of_rolls - How many times to roll the dice
>> #
>> # Output:
>> #    rolls - The array holding the values of the dice
>> #
>> ##############################################################################
>> #
>> function(die_size, number_of_dice, number_of_rolls)
>> {
>>       rolls <- array(0, dim=c(number_of_rolls, number_of_dice))
>>
>>       for (i in 1:number_of_rolls)
>>       {
>>               rolls[i,] <- sample(die_size, number_of_dice,  
>> replace=TRUE)
>>       }
>>
>>       return(rolls)
>> }
>>
>> Any thoughts on this function?  Is there a better way of doing it  
>> in R?  Can
>> you tell I used to play AD&D?
>>
>> Thanks,
>> Joe
>>
>> ______________________________________________
>> R-help at r-project.org mailing list
>> 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.
>>




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