Re: [Rd] Random number generation

From: Duncan Murdoch <>
Date: Tue, 05 Aug 2008 09:10:23 -0400

Please don't cross-post. This reply is going to R-devel only.

On 8/5/2008 8:47 AM, subramanian R wrote:
> Hi All,
> I have a few queries regarding Random Number generation in R.
> according to the help(Random.User) i defined my own functions for

That's help("Random.user")...

> user_unif_rand and user_norm_rand (uniform and normal distribution)
> But what i figured out was even when i call rexp,rpois,rgeom and
> other distributions they were routed via user_unif_rand.
> 1. Does this mean that for all types of distribution it generates an
> Uniform distribution and transforms to the requested type?
> Also surprisingly even rnorm which i hoped to route via user_norm_rand
> was calling user_unif_rand...

>> rnorm(1)

> inside user_unif_rand//printf and
> inside user_unif_rand
> [1] 0.5973648
> Please help me out understanding this...

I think you didn't do things properly, but you didn't show us what you did. When I run the sample code in help("Random.user"), adding an Rprintf() call to the user_norm_rand function, I see it being called.

Duncan Murdoch

> 2. Our goal is to link with an vectorized Random number generator library
> for our multi-core architecture.
> So is it enough if we define user_unif_rand function alone and will it
> take care of all distributions?
> Thanks in Anticipation,
> R. Subramanian
> [[alternative HTML version deleted]]
> ______________________________________________
> mailing list
> mailing list Received on Tue 05 Aug 2008 - 13:13:13 GMT

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