On Jul 26, 2012, at 10:06 AM, FJ M wrote:
It would be a useful additon to the help page to add
integrate(dnorm, lower = -1.96, upper = 1.96, mean = 2, sd = 1)
Wouldn't most statisticians instead use the more accurate and
undoubtedly faster:
pnorm(1.96, mean=2, sd=1) - pnorm(-1.96, mean=2, sd=1)
... or p_xxx where _xxx is distribution of interest?
(And I do not see that every help page needs a worked example of the
proper use of the 'dots' argument. That is a basic R lesson and it is
only by chance that you have needed to learn it in the context of
integrate(). A large fraction of other functions offer that facility.
You might review the material you used when learning R to see at what
point you skimmed over that crucial topic too quickly. )
--
David
Alameda.
as an example.
Thanks,
Frank
Chicago
Date: Mon, 23 Jul 2012 19:54:45 -0700
From: ehl...@ucalgary.ca
To: kri...@ymail.com
CC: chicagobrownb...@hotmail.com; r-help@r-project.org
Subject: Re: [R] Integrate(dnorm) with different mean and standard
deviation help
On 2012-07-23 19:48, Pascal Oettli wrote:
Hello,
Maybe the following could help:
f <- function(x) dnorm(x, mean=2, sd=1)
integrate(f, -1.96, 1.96)
0.4840091 with absolute error < 1.4e-12
Or you could note the '...' argument indicated on the help page:
integrate(dnorm, lower = -1.96, upper = 1.96,
mean = 2, sd = 1)
Peter Ehlers
HTH
Regards.
Le 24/07/2012 11:23, FJ M a écrit :
I'm trying to provide different parameters to the integrate
function for various probability functions. I'm using dnorm as
the simplest example here. For instance integrate(dnorm, -1.96,
1.96) produces the correct answer for a normal distribution with
mean 0 and standard deviation 1. I've tried two ways to use
mean=2.0 and standard deviation 1, but with no luck. The examples
follow.
integrate(dnorm, -1.96, 1.96)
0.9500042 with absolute error < 1e-11
mean = 2.0
sd = 1.0
integrate(dnorm, -1.96, 1.96)
0.9500042 with absolute error < 1e-11
integrate(dnorm(mean=2.0,sd=1.0), -1.96, 1.96)
Error in .Internal(dnorm(x, mean, sd, log)) : 'x' is missing
Calls: integrate -> match.fun -> dnorm
Execution halted
How do I change the built in mean=0 and standard deviation=1 for
dnorm using integrate?
Thanks,
Frank
Chicago, IL
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______________________________________________
R-help@r-project.org mailing list
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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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______________________________________________
R-help@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
Alameda, CA, USA
______________________________________________
R-help@r-project.org mailing list
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PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.
