PROTECTED]
Sent: Saturday, October 25, 2008 11:36 AM
To: Steven McKinney
Cc: A.Noufaily; r-help@r-project.org
Subject: Re: [R] Computational problems in R
On 24/10/2008 9:50 PM, Steven McKinney wrote:
I suspect there's a deeper issue here.
sum(exp(yi)) when large yi occur is
problematic. exp(yi
]
Sent: Tue 10/28/2008 12:58 AM
To: A.Noufaily
Cc: Duncan Murdoch; r-help@r-project.org; [EMAIL PROTECTED]; Steven McKinney;
Xiaoxu LI
Subject: Re: [R] Computational problems in R
Hello.
The Brobdingnag package uses that identity for a logarithmic
representation and also has a hack for negative
.
However, I might still use logs in case (1 + B/A)0.
Regards,
Amy
-Original Message-
From: Duncan Murdoch [mailto:[EMAIL PROTECTED]
Sent: Saturday, October 25, 2008 11:36 AM
To: Steven McKinney
Cc: A.Noufaily; r-help@r-project.org
Subject: Re: [R] Computational problems in R
On 24/10
-8000 x7561
BCCRC
Molecular Oncology
675 West 10th Ave, Floor 4
Vancouver B.C.
V5Z 1L3
Canada
-Original Message-
From: [EMAIL PROTECTED] on behalf of Duncan Murdoch
Sent: Fri 10/24/2008 4:04 PM
To: A.Noufaily
Cc: r-help@r-project.org
Subject: Re: [R] Computational problems in R
On 24
Dear all,
I would be grateful if anyone can help me with the following:
My aim is to compute explicitely the sum S=A+B where A=sum(exp(c_i/d)),
i=1,...,n;
B, c_i, and d are real numbers with -InfB,c_i+Inf; and d0.
The problem is that when c_i/d 710 (for some i) R is setting
exp(c_i/d) to be
I think you should try one X for A/X=sum(exp(c_i/d -log(X)))
The optional X could be as the following ...
## to test ### C = c(c_i/d; i=1,2,...,n)
n-1000;
C-runif(n,700,1000);
#
M-1;while (2*M Inf) M-2*M;
X- exp(max(C) - log (M/n));
cat('A=',sum(exp(C-log(X))),'*',X)
On
On 24/10/2008 12:42 PM, A.Noufaily wrote:
Dear all,
I would be grateful if anyone can help me with the following:
My aim is to compute explicitely the sum S=A+B where A=sum(exp(c_i/d)),
i=1,...,n;
B, c_i, and d are real numbers with -InfB,c_i+Inf; and d0.
The problem is that when c_i/d 710
.
V5Z 1L3
Canada
-Original Message-
From: [EMAIL PROTECTED] on behalf of Duncan Murdoch
Sent: Fri 10/24/2008 4:04 PM
To: A.Noufaily
Cc: r-help@r-project.org
Subject: Re: [R] Computational problems in R
On 24/10/2008 12:42 PM, A.Noufaily wrote:
Dear all,
I would be grateful
8 matches
Mail list logo
