R help - Apr 2011 - how to generate a normal distribution with mean=1, min=0.2, max=0.8

Dear all,

This is a simple probability problem. I want to know, How to generate a
normal distribution with mean=1, min=0.2 and max=0.8?

I know how the generate a normal distribution of mean = 1 and sd = 1 and
with 500 data point.

rnorm(n=500, m=1, sd=1)

But, I am confusing with how to generate a normal distribution with expected
min and max. I expect to hear your directions.

Thanks in advance.

Best,
Jian-Feng,

	[[alternative HTML version deleted]]

Surely you must be joking, Mr. Jianfeng.

-------------------------------------------------------
Ravi Varadhan, Ph.D.
Assistant Professor,
Division of Geriatric Medicine and Gerontology School of Medicine Johns Hopkins
University

Ph. (410) 502-2619
email: rvaradhan at jhmi.edu


-----Original Message-----
From: r-help-bounces at r-project.org [mailto:r-help-bounces at r-project.org]
On Behalf Of Mao Jianfeng
Sent: Thursday, April 28, 2011 12:02 PM
To: r-help at r-project.org
Subject: [R] how to generate a normal distribution with mean=1, min=0.2, max=0.8

Dear all,

This is a simple probability problem. I want to know, How to generate a
normal distribution with mean=1, min=0.2 and max=0.8?

I know how the generate a normal distribution of mean = 1 and sd = 1 and
with 500 data point.

rnorm(n=500, m=1, sd=1)

But, I am confusing with how to generate a normal distribution with expected
min and max. I expect to hear your directions.

Thanks in advance.

Best,
Jian-Feng,

	[[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.

On Apr 28, 2011, at 12:09 PM, Ravi Varadhan wrote:
> Surely you must be joking, Mr. Jianfeng.
>
Perhaps not joking and perhaps not with correct statistical  
specification.

A truncated Normal could be simulated with:

set.seed(567)
x <- rnorm(n=50000, m=1, sd=1)
xtrunc <- x[x>=0.2 & x <=0.8]
require(logspline)
plot(logspline(xtrunc, lbound=0.2, ubound=0.8, nknots=7))

-- 
David.
> -------------------------------------------------------
> Ravi Varadhan, Ph.D.
> Assistant Professor,
> Division of Geriatric Medicine and Gerontology School of Medicine  
> Johns Hopkins University
>
> Ph. (410) 502-2619
> email: rvaradhan at jhmi.edu
>
>
> -----Original Message-----
> From: r-help-bounces at r-project.org [mailto:r-help-bounces at
r-project.org
> ] On Behalf Of Mao Jianfeng
> Sent: Thursday, April 28, 2011 12:02 PM
> To: r-help at r-project.org
> Subject: [R] how to generate a normal distribution with mean=1,  
> min=0.2, max=0.8
>
> Dear all,
>
> This is a simple probability problem. I want to know, How to  
> generate a
> normal distribution with mean=1, min=0.2 and max=0.8?
>
> I know how the generate a normal distribution of mean = 1 and sd = 1  
> and
> with 500 data point.
>
> rnorm(n=500, m=1, sd=1)
>
> But, I am confusing with how to generate a normal distribution with  
> expected
> min and max. I expect to hear your directions.
>
> Thanks in advance.
>
> Best,
> Jian-Feng,
>
> 	[[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.
>
> ______________________________________________
> 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.
David Winsemius, MD
West Hartford, CT

That method (creating lots of samples and throwing most of them away) is 
usually frowned upon :-).

Try this:  (I haven't, so it may well have syntax errors)

% n28<- dnorm(seq(.2,.8,by=.001),mean=1,sd=1)

% x <- sample(seq(.2,.8,by=.001), size=500,replace=TRUE, prob=n28)

And I guess in retrospect this  will get really ugly if you want, say, a 
sampling grid resolution of 1e-6 or so.

Anyone know what's applicable from the "sampling" package?


Carl

-------<quote>__________________
From: David Winsemius <dwinsemius_at_comcast.net>
Date: Thu, 28 Apr 2011 13:06:21 -0400

On Apr 28, 2011, at 12:09 PM, Ravi Varadhan wrote:

 > Surely you must be joking, Mr. Jianfeng.
 >

Perhaps not joking and perhaps not with correct statistical specification.

A truncated Normal could be simulated with:

set.seed(567)
x <- rnorm(n=50000, m=1, sd=1)
xtrunc <- x[x>=0.2 & x <=0.8]
require(logspline)
plot(logspline(xtrunc, lbound=0.2, ubound=0.8, nknots=7))

-- 
David.




 > -----Original Message-----

 > From: r-help-bounces_at_r-project.org 
[mailto:r-help-bounces_at_r-project.org

 > ] On Behalf Of Mao Jianfeng



 > Dear all,

 >

 > This is a simple probability problem. I want to know, How to

 > generate a

 > normal distribution with mean=1, min=0.2 and max=0.8?

 >

Well, but the original poster also refers to 0.2 and 0.8 as "expected
 min and max", in which case we are back to a joke...

Giovanni


On Thu, 2011-04-28 at 13:06 -0400, David Winsemius
wrote:
> On Apr 28, 2011, at 12:09 PM, Ravi Varadhan wrote:
> 
> > Surely you must be joking, Mr. Jianfeng.
> >
> 
> Perhaps not joking and perhaps not with correct statistical  
> specification.
> 
> A truncated Normal could be simulated with:
> 
> set.seed(567)
> x <- rnorm(n=50000, m=1, sd=1)
> xtrunc <- x[x>=0.2 & x <=0.8]
> require(logspline)
> plot(logspline(xtrunc, lbound=0.2, ubound=0.8, nknots=7))
> 
> -- 
> David.
> 
> > -------------------------------------------------------
> > Ravi Varadhan, Ph.D.
> > Assistant Professor,
> > Division of Geriatric Medicine and Gerontology School of Medicine  
> > Johns Hopkins University
> >
> > Ph. (410) 502-2619
> > email: rvaradhan at jhmi.edu
> >
> >
> > -----Original Message-----
> > From:
> r-help-bounces at r-project.org [mailto:r-help-bounces at r-project.org 
> > ] On Behalf Of Mao Jianfeng
> > Sent: Thursday, April 28, 2011 12:02 PM
> > To: r-help at r-project.org
> > Subject: [R] how to generate a normal distribution with mean=1,  
> > min=0.2, max=0.8
> >
> > Dear all,
> >
> > This is a simple probability problem. I want to know, How to  
> > generate a
> > normal distribution with mean=1, min=0.2 and max=0.8?
> >
> > I know how the generate a normal distribution of mean = 1 and sd >
1
> > and
> > with 500 data point.
> >
> > rnorm(n=500, m=1, sd=1)
> >
> > But, I am confusing with how to generate a normal distribution
> with  
> > expected
> > min and max. I expect to hear your directions.
> >
> > Thanks in advance.
> >
> > Best,
> > Jian-Feng,
> >
> >       [[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.
> >
> > ______________________________________________
> > 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.
> 
> David Winsemius, MD
> West Hartford, CT
> 
> ______________________________________________
> 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.
> 
> 
-- 

Giovanni Petris  <GPetris at uark.edu>
Associate Professor
Department of Mathematical Sciences
University of Arkansas - Fayetteville, AR 72701
Ph: (479) 575-6324, 575-8630 (fax)
http://definetti.uark.edu/~gpetris/