[R] if statement and truncated distribution

[Nick Sabbe]

What I guess you want is something like (this is for zero-truncation):

rZeroTruncNormal1d<-function(mu, sig, invalidSign) #sig holds standard
deviation!
{
	val<-rnorm(1, mu, sig)
	while(val * invalidSign > 0)
	{
		val<-rnorm(1, mu, sig)
	}
	return(val)
}


Nick Sabbe
--
ping: nick.sabbe at ugent.be
link: http://biomath.ugent.be
wink: A1.056, Coupure Links 653, 9000 Gent
ring: 09/264.59.36

-- Do Not Disapprove




-----Original Message-----
From: r-help-bounces at r-project.org [mailto:r-help-bounces at r-project.org] On
Behalf Of Sally Luo
Sent: maandag 25 oktober 2010 2:01
To: r-help at r-project.org
Subject: [R] if statement and truncated distribution

Hi R helpers,

I am trying to use the if statement to generate a truncated random variable
as follows:

if (y[i]==0)  { v[i] ~ rnorm(1,0,1) | (-inf ,0) }
if (y[i]==1) { v[i] ~ rnorm(1,0,1) | (0, inf) }

I guess I cannot use " | (  , ) " to restrict the range of a variable in R.
Could you let me know how to write the code correctly in R?

Many thanks for your help.

Maomao

	[[alternative HTML version deleted]]

______________________________________________
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.