Displaying 20 results from an estimated 400 matches similar to: "R accuracy"
2006 Jul 14
2
References verifying accuracy of R for basic statisticalcalculations and tests
Hi,
> [mailto:r-help-bounces at stat.math.ethz.ch] On Behalf Of Corey Powell
>
> Do you know of any references that verify the accuracy of R
> for basic statistical calculations and tests. The results of
> these studies should indicate that R results are the same as
> the results of other statistical packages to a certain number
> of decimal places on some benchmark
2005 Jun 27
2
Numerical accuracy
Hi people,
I need to prove the good quality of numerical accuracy of R. Anyone knows a
paper or anything else comparing R to other statistical softwares in terms of
numerical accuracy.
I've made a long search about that but I found nothing. Please help me!!
Thanx,
Talita Leite
-------------------------------------------------
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IMP:
2005 Mar 18
1
Pb with ks.test pvalue
Hello,
While doing test of normality under R and SAS, in order to prove the efficiency of R to my company, I notice
that Anderson Darling, Cramer Van Mises and Shapiro-Wilk tests results are quite the same under the two environnements,
but the Kolmogorov-smirnov p-value really is different.
Here is what I do:
> ks.test(w,pnorm,mean(w),sd(w))
One-sample Kolmogorov-Smirnov test
data: w
D
2005 Apr 06
1
nls.control
Hello everyone,
I'm trying to test the accurracy of R on the Eckerle4 dataset from NIST and
I don't understand how the control option of the nls function works.
I tought nls(...) was equivalent to nls(...control=nls.control()) i.e nls.control() was the default value of control, but here is the error I get :
> n2=nls(V1~(b1/b2) *
2006 Jul 30
2
NIST StRD linear regression
NIST maintains a repository of Statistical Reference Datasets at
http://www.itl.nist.gov/div898/strd/. I have been working through the
datasets to compare R's results to their references with the hope that
if all works well, this could become a validation package.
All the linear regression datasets give results with some degree of
accuracy except one. The NIST model includes 11 parameters,
2012 May 04
3
read-in, error???
Dear Users!
I encountered with some problem in data reading while I challenged R (and
me too) in a validation point of view.
In this issue, I tried to utilize some reference datasets (
http://www.itl.nist.gov/div898/strd/index.html).
And the result departed a bit from my expectations. This dataset dedicated
to challenge cancellation and accumulation errors (case SmLs07), that's why
this
2004 Apr 02
3
Single Factor Anova
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Hash: SHA1
Hello all -
As I progress in R I am trying to automate functions I would have
normally farmed out to Excel, SPSS or Statistica. Single factor anova
is one of them. For example, a dataset from NIST StRD
(http://www.itl.nist.gov/div898/strd/anova/AtmWtAg.html) has two groups:
1 2
107.8681568 107.8681079
107.8681465 107.8681344
2012 May 11
0
NLS sensitivity to start= values or poles in data range
Greetings R-help! I'm fairly new to R and am trying to expand my knowledge beyond using R for simple summary statistics and basic tests. To that end I am attempting to write an interactive R-script that will perform a general rational function fit to a given dataset based on the example given at http://www.itl.nist.gov/div898/handbook/pmd/section6/pmd64.htm.
The problem that I seem to have
2003 Sep 04
0
SUMMARY: Comparison of SAS & R/Splus
My thanks to Drs. Armstrong, Bates, Harrell, Liaw, Lumley,
Prager, Schwartz, and Mr. Wang for their replies. I have
pasted my original message and their replies below.
After viewing http://www.itl.nist.gov/div898/strd/ as suggested
by Dr. Schwartz, it occurred to me that it might be educational
to search for some data repositories on google. I was able to find
some,though I'm sure many of
2008 May 29
3
Datasets in R
I?m trying to find datasets that will give me residuals, after applying
the lm function, with no normality, non linearity, and heteroscedacity
so I can try to exemplify
those cases in the linear regression model. Can you give any advice on
what datasets would be appropiate? I can?t use the ones in the alr3
package because those have
already been seen in class.
Thank you very much :-)
natorro
2001 Jan 10
2
Levenberg-Marquardt algorithm
Hi All,
Is the Levenberg-Marquardt algorithm available in R. This method combines the
steepest descent algorithm and Newton's method.
Thanks in Advance,
Dermot MacSweeney.
**************************************************************
Dermot MacSweeney NMRC,
Email: dsweeney at nmrc.ucc.ie Lee Maltings,
Tel: +353 21 904178 Prospect Row,
Fax: +353 21 270271 Cork,
WWW:
2011 Oct 23
0
FW: Re: symmetric matrix multiplication
Just to avoid possible confusion, let me correct a typo
(at step [2] in the example below). Apologies!
-----FW: <XFMail.111023084327.ted.harding at wlandres.net>-----
Date: Sun, 23 Oct 2011 08:43:27 +0100 (BST)
Sender: r-help-bounces at r-project.org
From: (Ted Harding) <ted.harding at wlandres.net>
To: r-help at r-project.org
Subject: Re: [R] symmetric matrix multiplication
On
2013 Feb 20
3
NLS results different from Excel -- Tricky fortunes nomination
Folks:
I thought the following excerpt from Bruce McCullough's post would be
a good candidate for the R fortunes package -- except that it's about
Excel, not R! So I nominate it... but leave it to others to say
whether it's really "qualified" to be nominated.
----
"The idea that the Excel solver "has a good reputation for being fast
and accurate" does not
2013 Feb 20
1
NLS results different from Excel
The idea that the Excel solver "has a good reputation for being fast and
accurate" does not withstand an examination of the Excel solver's
ability to solve the StRD nls test problems. Solver's ability is
abysmal. 13 of 27 "answers" have zero accurate digits, and three more
have fewer than two accurate digits -- and this is after tuning the
solver to get a good
2012 Jan 23
2
[LLVMdev] Use of 'ldrd' instructions with unaligned addresses on armv7 (Major bug in LLVM optimizer?)
Hi,
I think I discovered a major armv7 optimization bug in Clang. I create a simple test case which exhibits the issue.
When you compile the attached file for armv7 with optimizations turned on (O2, O3 or Os), the binary generated led to a crash.
The issue can't be reproduced when using GCC 4.2. It can't be reproduced with Clang when the optimization is turned off (O0).
This issue can be
2007 Jul 04
2
probabilty plot
Hi all,
I am a freshman of R,but I am interested in it! Those days,I am
learning pages on NIST,with url
http://www.itl.nist.gov/div898/handbook/eda/section3/probplot.htm,
I am meeting a problem about probability plot and I don't know how to
plot a data set with R.
Could somebody tell me the answer,and a example is the best! I will
look forward to your answer.
Thank you very much.
2012 Jun 25
2
Fractional Factorial - Wrong values using lm-function
Hello.
I'm a new user of R, and I have a question regarding the use of aov and
lm-functions. I'm doing a fractional factorial experiment at our production
site, and I need to familiarize myself with the analysis before I conduct
the experiment. I've been working my way through the examples provided at
http://www.itl.nist.gov/div898/handbook/pri/section4/pri472.htm
2012 Jan 23
0
[LLVMdev] Use of 'ldrd' instructions with unaligned addresses on armv7 (Major bug in LLVM optimizer?)
The problem is in your code, not the compiler. You're casting an unaligned char* to an int*, even though an int* pointer must be 4-byte aligned in every ARM ABI that I've ever seen.
On Jan 23, 2012, at 6:14 AM, Alexandre Colucci wrote:
> Hi,
>
> I think I discovered a major armv7 optimization bug in Clang. I create a simple test case which exhibits the issue.
> When you
2013 Oct 08
1
how to check the accuracy for maxent ?
I was going through this example of maxent use:
http://cran.r-project.org/web/packages/maxent/maxent.pdf
# LOAD LIBRARY
library(maxent)
# READ THE DATA, PREPARE THE CORPUS, and CREATE THE MATRIX
data <- read.csv(system.file("data/NYTimes.csv.gz",package="maxent"))
corpus <- Corpus(VectorSource(data$Title[1:150]))
matrix <- DocumentTermMatrix(corpus)
# TRAIN/PREDICT
2012 Sep 13
1
Package for comparing sensitivity, specificity, PPV, NPV, and accuracy?
Hi, I have two sets of sensitivity, specificity, positive predictive
value, and negative predictive value, and accuracy from two tests on
the same subjects. Is there an R package that does such paired
comparisons?
Thanks,
Gang Chen