Displaying 20 results from an estimated 600 matches similar to: "chisq test and fisher exact test"
2005 Jun 24
1
comparing strength of association instead of strength of evidence?
Hi,
I asked this question before, which was hidden in a bunch of
questions. I repharse it here and hope I can get some help this time:
I have 2 contingency tables which have the same group variable Y. I
want to compare the strength of association between X1/Y and X2/Y. I
am not sure if comparing p-values IS the way even though the
probability of seeing such "weird" observation under H0
2007 Nov 09
1
fisher.test, chisq.test
Hi,
I want to analyse a contigency table (3 x 12) with a fisher.test
beacause there are cells that are less than 5.
?mmen Anken Baf Belchen H?chi Hof Porti R?m Schmutz Sch?n Sissa Tann
class14 7 26 150 2 46 68 126 66 3 31 7 61
class24 7 6 55 5 49 71 93 90 1 18 16 79
class34 1 1 4 3 19 8 29 61
2010 Aug 12
2
Difference in Monte Carlo calculation between chisq.test and fisher.test
Hello all,
I would like to know what the difference is between chisq.test and
fisher.test when using the Monte Carlo method with simulate.p.value=TRUE?
Thank you
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2005 Jun 15
1
coding to generate a matrix to prepare for chi-sqr test f or text mining
I would compile a table of all the words in the dataset (maybe you have it
already), then create a list where each component is an integer vector of
indices of words. That is, replace words by their positions in the table.
>From that sparse form you could create binary features to use with standard
classification methods, or for example compute the X'X matrix for linear
regression
2007 May 10
0
getting the normal dist from the chisqr with 1df
l used the following code to generate a sample and then calculated then did a log rank test.can l get the normal version of the logrank eg sqrt of the chisqr(1) will give you the N~(0,1).
from my sample can i use the above expression to get the normal dist from the result of the log rank test.
thank
s=1
while(s!=0){ n=100
m<-matrix(nrow=n,ncol=4)
2005 Jun 15
0
coding to generate a matrix to prepare for chi-sqr test for text mining
Hi, there:
I have a dataset like the following:
1412|WINDOW|SHATTER|TORN|SOFT|TOP|WATER|RAIN|LAB|AI|BOLL|CAMP|0
1413|PARK|IV|STRUCK|PARK|PUSH|COD|POLICI|CIA|TB|SIC|0
2412|ACCID|REAREND|MULTI|EH|IV|MIDDL|FAN|DUAL|LOSS|CALM|1
2414|IV|REAREND|CD|COG|LAB|ADVERS|1
2415|ACCID|SINGL|VEHICL|IV|SWERV|AVOID|OBJECT|STRUCK|PHONE|POLE|FAN|0
2417|ACCID|SINGL|VEHICL|ROLL|DUE|FATAL|FAN|DUAL|LOSS|CALM|1
2011 Apr 05
1
NUT upgrade to 2.6.0 in Gentoo with Liebert UPS
I have a 64 bit Gentoo, with a Liebert UPS. The last NUT working version
was sys-power/nut-2.4.1-r1 (I also tried sys-power/nut-2.4.3-r2 but
downgraded, don't remember the reason).
Anyway with the upgrade to sys-power/nut-2.6.0 I started to see this
error message when I try to start upsdrv:
[root at aemaeth:/etc/nut]$ /etc/init.d/upsdrv start
* Starting UPS drivers ...
Network UPS Tools -
2012 Jun 19
1
weird --no 'dimnames' attribute for array-- error for R lordif package
Hi All,
? I am trying to use the lordif package in R and can't figure out the reason for the above error when I try to run the calctheta() function.
##################
# read data using foreign package - must be Stata 11 or earlier
racedata<- read.dta("race.dta")???
# item responses
resp.data<-racedata[,-c(1:2)]
# grouping variable is in the second column
2009 Dec 09
5
[Bug 25527] New: The console doesn't work with Nouveau and KMS on a 9400M
http://bugs.freedesktop.org/show_bug.cgi?id=25527
Summary: The console doesn't work with Nouveau and KMS on a 9400M
Product: xorg
Version: 7.5
Platform: x86-64 (AMD64)
OS/Version: Linux (All)
Status: NEW
Severity: major
Priority: medium
Component: Driver/nouveau
AssignedTo: nouveau at
2003 Mar 27
0
a statistic question about chisq.test() (aprilsun)
The Chisquare test is based upon a normal approx of the (essentially) binomial
distribution for the data in question. Small EXPECTED (not observed) values
(<5) suggest a asymetric distribution and potential errors in inferential
conclusions. The alternative is the exact test, which calculates the exact
probabilities of the observed distribution, or a more extreme one, given the
constraining
2002 Dec 02
1
Monte Carlo chisq test
Dear all,
I have a question about the chisq.test command. As an option one can
chose the computation of p-values by Monte-Carlo simulation
(simulate.p.value=T). Is there any documentation available how this
calculations are done and how this simulation based test behaves in
small samples?
Thanks
Klaus Abberger
University of Konstanz, Germany
[[alternate HTML version deleted]]
2017 Dec 27
0
Numerical stability in chisq.test
The chisq.test contains following code:
STATISTIC <- sum(sort((x - E)^2/E, decreasing = TRUE))
However, based on book Accuracy and stability of numerical algorithms <http://ftp.demec.ufpr.br/CFD/bibliografia/Higham_2002_Accuracy%20and%20Stability%20of%20Numerical%20Algorithms.pdf> Table 4.1 on page 89, it is better to sort the data in increasing order than in decreasing order, when the
2002 Dec 04
1
documentation bug in (ctest) chisq.test (PR#2346)
chisq.test with simulate.p.value=TRUE uses the Patefield algorithm, this
is not documented, and the original reference is not given, as it ought
to be. The reference is:
Patefield,W. M. (1981) An efficient method of generating r * c tables
with given row and column totals (algorithm AS 159). Applied Statistics
30, 91-97.
Kjetil Halvorsen
2003 Jul 16
1
The two chisq.test p values differ when the contingency table is transposed! (PR#3486)
Full_Name: Tao Shi
Version: 1.7.0
OS: Windows XP Professional
Submission from: (NULL) (149.142.163.65)
> x
[,1] [,2]
[1,] 149 151
[2,] 1 8
> c2x<-chisq.test(x, simulate.p.value=T, B=100000)$p.value
> for(i in (1:20)){c2x<-c(c2x,chisq.test(x,
simulate.p.value=T,B=100000)$p.value)}
> c2tx<-chisq.test(t(x), simulate.p.value=T, B=100000)$p.value
> for(i in
2003 Aug 21
0
The two chisq.test p values differ when the contingency table (PR#3896)
>>>>> dmurdoch writes:
>> Date: Wed, 16 Jul 2003 01:27:25 +0200 (MET DST)
>> From: shitao@ucla.edu
>>> x
>> [,1] [,2]
>> [1,] 149 151
>> [2,] 1 8
>>> c2x<-chisq.test(x, simulate.p.value=T, B=100000)$p.value
>>> for(i in (1:20)){c2x<-c(c2x,chisq.test(x,
>> simulate.p.value=T,B=100000)$p.value)}
2003 Dec 11
0
Re: [R] chisq.test freezing on certain inputs (PR#5701)
On Thu, 11 Dec 2003, Jeffrey Chang wrote:
> Hello everybody,
>
> I'm running R 1.8.1 on both Linux and OS X compiled with gcc 3.2.2 and
> 3.3, respectively. The following call seems to freeze the interpreter
> on both systems:
> > chisq.test(matrix(c(233, 580104, 3776, 5786104), 2, 2),
> simulate.p.value=TRUE)
>
> By freeze, I mean, the function call never
2003 Dec 11
0
Re: [R] chisq.test freezing on certain inputs (PR#5701)
>>>>> "Torsten" == Torsten Hothorn <torsten@hothorn.de>
>>>>> on Thu, 11 Dec 2003 18:03:07 +0100 (CET) writes:
Torsten> On Thu, 11 Dec 2003, Jeffrey Chang wrote:
>> Hello everybody,
>>
>> I'm running R 1.8.1 on both Linux and OS X compiled with
>> gcc 3.2.2 and 3.3, respectively. The following
2003 Dec 13
0
chisq.test() and r2dtable() freezing on certain inputs (PR#5701)
>>>>> "MM" == Martin Maechler <maechler@stat.math.ethz.ch>
>>>>> on Thu, 11 Dec 2003 18:29:05 +0100 (CET) writes:
>>>>> "Torsten" == Torsten Hothorn <torsten@hothorn.de>
>>>>> on Thu, 11 Dec 2003 18:03:07 +0100 (CET) writes:
Torsten> On Thu, 11 Dec 2003, Jeffrey Chang wrote:
2013 Jul 09
0
probable bugs in stats::loglin calculation of pearson chisq
In running the following example of a loglinear model for the Titanic data,
I was surprised to see NaN reported for the
Pearson chisq
> loglin(Titanic, margin=list(1:3, 4))
2 iterations: deviation 2.273737e-13
$lrt
[1] 671.9622
$pearson
[1] NaN
$df
[1] 15
$margin
$margin[[1]]
[1] "Class" "Sex" "Age"
$margin[[2]]
[1] "Survived"
Tracing it back,
2017 Dec 28
0
Numerical stability in chisq.test
>>>>> Jan Motl writes:
> The chisq.test on line 57 contains following code:
> STATISTIC <- sum(sort((x - E)^2/E, decreasing = TRUE))
The preceding 2 lines seem relevant:
## Sorting before summing may look strange, but seems to be
## a sensible way to deal with rounding issues (PR#3486):
STATISTIC <- sum(sort((x - E) ^ 2 / E,