R help - Oct 2007 - Sample selection problem

I want to get a sample of some arbitrary size from a population having only two
values 0 and 1 with replacement, but with different probability for selection.
For example 0 will be selected with probability 0.4 and 1 with 0.6. I could use
sample function i.e. sample(c(0,1), 30, T) to get this, however here, selection
of either 0 or 1 has equal probability here. I am looking for a function which
can do the same thing but with different probabilities.
       
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Hi,

Can't you do something like:

x <- c(1,1,1,1,1,1,0,0,0,0)
sample(x, 30, T)

Best Wishes,

Jenny
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>I want to get a sample of some arbitrary size from a population having only
two
values 0 and 1 with replacement, but with different probability for selection. 
For example 0 will be selected with probability 0.4 and 1 with 0.6. I could use 
sample function i.e. sample(c(0,1), 30, T) to get this, however here, selection 
of either 0 or 1 has equal probability here. I am looking for a function which 
can do the same thing but with different probabilities.
>       
>---------------------------------
> Meet people who discuss and share your passions.  Join them now.
>	[[alternative HTML version deleted]]
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~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Jennifer Barnes
PhD student: long range drought prediction 
Climate Extremes Group
Department of Space and Climate Physics
University College London
Holmbury St Mary 
Dorking, Surrey, RH5 6NT
Tel: 01483 204149
Mob: 07916 139187
Web: http://climate.mssl.ucl.ac.uk

On 10/3/07, stat stat <stat700004 at yahoo.co.in>
wrote:
> I want to get a sample of some arbitrary size from a population having only
two values 0 and 1 with replacement, but with different probability for
selection. For example 0 will be selected with probability 0.4 and 1 with 0.6. I
could use sample function i.e. sample(c(0,1), 30, T) to get this, however here,
selection of either 0 or 1 has equal probability here. I am looking for a
function which can do the same thing but with different probabilities.
>
either ?sample (see "prob" argument), or ?rbinom

/Gustaf

-- 
Gustaf Rydevik, M.Sci.
tel: +46(0)703 051 451
address:Essingetorget 40,112 66 Stockholm, SE
skype:gustaf_rydevik