Displaying 20 results from an estimated 4000 matches similar to: "probable bugs in stats::loglin calculation of pearson chisq"
2013 Jul 06
0
fitting the null loglinear model with MASS::loglm??
The null loglinear model is an intercept-only model for log frequency,
log(f) = \mu
For a one-way table the test of the null model is the same as the
chisq.test.
This can be fit using loglin(), but I don't think there is any way to
specify this using MASS::loglm
> t1<- margin.table(Titanic,1)
> t1
Class
1st 2nd 3rd Crew
325 285 706 885
> loglin(t1, NULL)
0
2015 Oct 22
0
C_LogLin (stats/loglin)
Kai,
Apologies for the double message, it didn't go to the list last time.
On Thu, Oct 22, 2015 at 9:59 AM, Kai Nitschke <
kai.nitschke at uniklinik-freiburg.de> wrote:
>
> ?.Call? calls the C/C++ function ?C_LogLin?. But when I am running it line
> by line I get
> the following error on line 23/24:
> Error: object 'C_LogLin' not found
>
> Hence, my
1999 May 23
0
Bug in loglin with variable called "c" (PR#198)
Summary:
loglin will fail if there is a global variable called c. I have
fixed this for 0.64.2 and 0.65.
On Sat, 22 May 1999, Cor en Aylin wrote:
> Dear Brian,
>
> Using the mass library for R (the most recent port dated 16 may 1999) I
Could you give version numbers in such reports please: at the moment there
is an official version (5.3pl037) of MASS for R, plus a pre-release of MASS
2004 Jul 21
0
loglin( tab, margin, start = bad.start ) kills R (PR#7123)
> tab <- array( sample(3^5), rep(3,5) )
> loglin( tab, list(1,2,3,4,5) )[[1]] # AOK
2 iterations: deviation 5.456968e-12
[1] 10909.89
> loglin( tab, list(1,2,3,4,5), c(1,2,3) )[[1]] # OUCH!
Process R bus error at Wed Jul 21 17:03:55 2004
this is inconsistent - sometimes issuing this msg several times before
barfing:
Error in switch(z$ifault, stop("This should not
2011 Sep 15
4
question about glm vs. loglin()
Dear R gurus,
I am looking for a way to fit a predictive model for a contingency table which has counts. I found that glm( family=poisson) is very good for figuring out which of several alternative models I should select. But once I select a model it is hard to present and interpret it, especially when it has interactions, because everything is done "relative to reference cell". This
2015 Oct 22
2
C_LogLin (stats/loglin)
Hi everyone,
I have a question regarding a C function of the "stats" package in R.
I tried to understand the ?loglin? basic function of the ?stats?
package implemented in
R. The implemented function itself runs without any problem (perhaps
see sample). When I
ran it line by line it stopped at the lines 23-24 of the
loglin-function; (the following line):
z <- .Call(C_LogLin,
2010 Sep 22
0
bctrans: Box-Cox Transformation Problem
Hello,
I'm currently trying to model the movement of a slope (v.obs) with a
regression model.
The data can be found following the given links:
either
http://www.sendspace.com/file/dnugwc
or
http://rapidshare.com/files/420569660/sel.day.txt
I want to use the Box-Cox transformation to normalize the response as
well as the predictor variables.
The scatterplot looks like this:
library(zoo)
2008 Aug 10
1
(Un-)intentional change in drop1() "Chisq" behaviour?
Dear List,
recently tried to reproduce the results of some custom model selection
function after updating R, which unfortunately failed. However, I
ultimately found the issue to be that testing with pchisq() in drop1()
seems to have changed. In the below example, earlier versions (e.g. R
2.4.1) produce a missing P-value for the variable x, while newer
versions (e.g. R 2.7.1) produce 0 (2.2e-16).
2004 Jun 22
1
Grouped AND stacked bar charts possible in R?
Good day all,
My statisticians want an R procedure that will produce grouped stacked
barplots. Barplot will
stack or group, but not both. The ftable function can produce a table
of the exact form they want, but the barplot doesn't show all the
divisions we want.
For an example, here's the sample from the help file for "ftable:"
data(Titanic)
ftable(Titanic, row.vars = 1:3)
2003 Feb 03
1
summary.table bug in parameter (and fix) (PR#2526)
I sent this in with an old version, but it's in latest version as well. The fix is simple.
In the summary.table function, the parameter is calculated incorrectly
for a test of independence among all cells when the table is more than
2-way table.
Example:
Consider X:
> X
a b c
1 A1 B2 C1
2 A3 BA3 C2
3 A2 B1 C4
4 A1 B2 C3
5 A3 BA3 C2
6 A1 BA3 C1
7 A2 BA3 C2
8 A1
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
--
View this message in context: http://r.789695.n4.nabble.com/Difference-in-Monte-Carlo-calculation-between-chisq-test-and-fisher-test-tp2322494p2322494.html
Sent from the R help mailing list archive at Nabble.com.
2012 Feb 20
1
chisq.test vs manual calculation - why are different results produced?
Hello,
I am trying to fit gamma, negative exponential and inverse power functions
to a dataset, and then test whether the fit of each curve is good. To do
this I have been advised to calculate predicted values for bins of data (I
have grouped a continuous range of distances into 1km bins), and then apply
a chi-squared test. Example:
> data <- data.frame(distance=c(1,2,3,4,5,6,7),
2004 Dec 01
2
chisq.test probabilities method unclear
Hi list,
i've got a question about the chisq.test function.
in the use of the "given probabilities" method (p= ...), normally
there should be typed in probabilities in the range of 0 to 1 with the
absolute sum of 1.0 (r-help)
But it is possible to use probabilities > than 1. or the sum <1.!
without any warning message
Ok, now the question, what does r calcutate in these
2003 Jul 15
0
Why two chisq.test p values differ when the contingency
Hi Tao:
The P-values for 2x2 table are generated based on a random (discrete
uniform distribution) sampling of all possible 2x2 tables, conditioning
on the observed margin totals. If one of the cells is extremely small,
as in your case, you get a big difference in P-values. Suppose, you
changed the cell with value 1 to, say, 5 or 6, then the two P-values
are nearly the same. However, I
2003 Feb 28
0
(multiway) percentage tables
R has amazing capabilities, but percentage tables are a weak spot
IMHO. There's prop.table but that's rather unwieldly, especially for
multiway tables. CrossTable by Marc Schwartz in the gregmisc library
makes percentage tables a breeze but is limited to two-way tables. So
I decided to try my own hand at writing an R-function that would make
it easy to produce nicely formatted percentage
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 Dec 09
2
p-value from chisq.test working strangely on 1.8.1
Hello everybody,
I'm seeing some strange behavior on R 1.8.1 on Intel/Linux compiled
with gcc 3.2.2. The p-value calculated from the chisq.test function is
incorrect for some input values:
> chisq.test(matrix(c(0, 1, 1, 12555), 2, 2), simulate.p.value=TRUE)
Pearson's Chi-squared test with simulated p-value (based on 2000
replicates)
data: matrix(c(0, 1, 1,
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)}
2009 Feb 08
2
Using panel.grid in barchart
Hi all,
I'm trying to do an example in Deepayan Sarkar's Lattice book. It
involves making a barchart based on the Titanic dataset. I can get
the barchart to plot fine; however, when I try to edit panel.grid, I
get an error:
> titan<-barchart(Class ~ Freq | Age + Sex, data =
as.data.frame(Titanic), groups=Survived, stack=TRUE, layout=c(4,1),
2005 Jun 22
1
chisq test and fisher exact test
Hi,
I have a text mining project and currently I am working on feature
generation/selection part.
My plan is selecting a set of words or word combinations which have
better discriminant capability than other words in telling the group
id's (2 classes in this case) for a dataset which has 2,000,000
documents.
One approach is using "contrast-set association rule mining" while the