Hi there!
I'm not sure I can create a minimal example of my problem, so I'm linking to
a minimal .RData file that has only two objects: obs and exp, each is a 6x9
matrix. http://dl.dropbox.com/u/10364753/test.RData link to dropbox file
(I hope this is acceptable mailing list etiquette!)
Here's
-Original Message-
From: r-help-boun...@r-project.org [mailto:r-help-bounces@r-
project.org] On Behalf Of maiya
Sent: Thursday, March 10, 2011 7:19 AM
To: r-help@r-project.org
Subject: [R] identical values not so identical? newbie help please!
Hi there!
I'm not sure I can create
Hi Maja,
Values that are theoretically the same may not be exactly identical
when using floating point arithmetic. Please read this FAQ page:
http://cran.r-project.org/doc/FAQ/R-FAQ.html#Why-doesn_0027t-R-think-these-numbers-are-equal_003f
If you need to test that they are equal, you may add a
Thanks Josh and Dan!
I did figure it had something to do with the machine epsilon...
But so what do I do now? I'm calculating the total absolute error over
thousands of tables e.g.:
tae-sum(abs(obs-exp))
Is there any easy way to I keep these ignorable errors from showing up?
And furthermore,
On Thu, Mar 10, 2011 at 10:34 AM, maiya maja.zaloz...@gmail.com wrote:
Thanks Josh and Dan!
I did figure it had something to do with the machine epsilon...
But so what do I do now? I'm calculating the total absolute error over
thousands of tables e.g.:
tae-sum(abs(obs-exp))
Is there any
The function all.equal also might be helpful.
See the help page.
help(all.equal)
-David Johnston
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project.org] On Behalf Of maiya
Sent: Thursday, March 10, 2011 10:34 AM
To: r-help@r-project.org
Subject: Re: [R] identical values not so identical? newbie help please!
Thanks Josh and Dan!
I did figure it had something to do with the machine epsilon...
But so what do I do now? I'm
On Thu, Mar 10, 2011 at 10:34:21AM -0800, maiya wrote:
Thanks Josh and Dan!
I did figure it had something to do with the machine epsilon...
But so what do I do now? I'm calculating the total absolute error over
thousands of tables e.g.:
tae-sum(abs(obs-exp))
Is there any easy way to I
Aaah, it truly is wonderful, this technology!
I guess I'm going to have to override it a bit though..
Along the lines of
tae - ifesle(all.equal(obs, exp) == TRUE, 0, sum(abs(obs - exp)))
Do I like doing this? No. But short of reading the vast literature that
exists on calculation precision -
Quite fascinating, if annoying. Nice example Petr!
Turns out my expected values are causing even more trouble because of this!
I've even gotten negative chi square values (calculated using Cressie and
Read's formula)!
So instead of kludging the error measurement code, I think I'm going to have
G'day Maja,
On Thu, 10 Mar 2011 11:44:28 -0800 (PST)
maiya maja.zaloz...@gmail.com wrote:
Aaah, it truly is wonderful, this technology!
I guess I'm going to have to override it a bit though..
Along the lines of
tae - ifesle(all.equal(obs, exp) == TRUE, 0, sum(abs(obs - exp)))
Please read
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