Displaying 20 results from an estimated 400 matches similar to: "chi-squared with zero df (PR#10551)"
2004 Jan 19
2
small bug on qchisq (PR#6442)
Full_Name: Drouilhet R?my
Version: 1.8.1
OS: Linux
Submission from: (NULL) (195.221.43.136)
qchisq(1,10) works well but qchisq(1,10,ncp=0) does not work whereas ncp=0 is
the default value of the function qchisq(1,10). (of course, 10 will be replaced
by any integer value).
Let us notice that this bug occurs only when applying probability one.
(qchisq(seq(0,.9,.1),10,ncp=0) works very well).
2004 Sep 06
1
qchisq (PR#7212)
Full_Name: David Clayton
Version: 1.8.1
OS: Linux
Submission from: (NULL) (131.111.126.242)
qchisq behaves very strangely when ncp is passed as zero (forcing internal
qnchisq to be called) when first argument is small.
Eg
> qchisq(1-1e-6, 1, ncp=0, lower.tail=TRUE)
qchisq(1-1e-6, 1, ncp=0, lower.tail=TRUE)
[1] 1024
while, if ncp is unspecified,
> qchisq(1-1e-6, 1)
qchisq(1-1e-6, 1)
2003 Apr 13
2
Peculiarity in non-central qchisq for ncp > 294.92 ...
Hello all,
Here's my query:
Running R 1.6.2 on FreeBSD 5.0, and on WinXP, and I find that the
following hangs the process:
dchisq(alpha=0.01, df=1, ncp=295)
but it does work for ncp < 294.92.
Is this general?
Best wishes to all,
Andrew
Andrew Robinson Ph: 208 885 7115
Department of Forest Resources Fa: 208 885 6226
University of Idaho E : andrewr at uidaho.edu
PO
2003 Mar 08
2
Looking for non-central F quantile
Greetings all,
I'm trying to figure out how to calculate the inverse CDF (i.e. a
quantile) for a non-central F distribution. I could put together a quick
numerical solver routine using the CDF, but I wonder if there's a function
that I've missed that would be more efficient?
Thank-you,
Andrew
Andrew Robinson Ph: 208 885 7115
Department of Forest Resources Fa: 208 885
2001 Dec 09
1
Help for Power analysis
Dear colleague,
I not sure this R code is correctly ? I would to show
the number of Sample Size at Sample Size Axis that line
draw from Power Axis (80%) from R code.
How I show this and select the most appropriate of
this power (.79955687 - 80983575).
Thank for your help and answer.
Best Regards,
Nikom Thanomsieng,
Email: nikom at kku.ac.th
....
#Power analysis: Sample size for
2009 Oct 11
2
Accuracy (PR#13999)
Full_Name: Viktor Witkovsky
Version: 2.9.2
OS: Windows XP
Submission from: (NULL) (78.98.89.227)
Hello,
I have found strange behavior of the function qchisq (the non-central qchisq is
based on inversion of pchisq, which is further based on pgamma). The function
gives wrong results without any warning. For example:
qchisq(1e-12,1,8.94^2,lower.tail=FALSE) gives 255.1840972465858 (notice that
2005 Jun 15
1
Chi square convolution?
Hi,
I want to determine the confidence interval on the sum of two sigma's.
Is there an easy way to do this in R? I guess I have to use some sort of
chisquare convolution algorithm???
Thanx,
Roy
--
The information contained in this communication and any atta...{{dropped}}
2004 Aug 19
1
precision problems in testing with Intel compilers
I compiled the 1.9.1 src.rpm with the standard gnu tools and it works.
I tried compiling the 1.9.1 src.rpm with the Intel 8 C and FORTRAN
compilers and it bombs out during the testing phase:
comparing 'd-p-q-r-tests.Rout' to './d-p-q-r-tests.Rout.save' ...267c267
< df = 0.5[1] "Mean relative difference: 5.001647e-10"
---
> df = 0.5[1] TRUE
2008 Feb 07
3
how to calculate chisq value in R
for example, an expression such as chisq(df=1,ncp=0) ?
thanks
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Sent from the R help mailing list archive at Nabble.com.
2006 Jan 17
1
how can i locate the source code of a module quickly?
I have dowloaded the Source Code of R,and I want to know the process of
chi-sqared test,but how can I found it?
[[alternative HTML version deleted]]
2006 Feb 06
3
power and sample size for a GLM with poisson response variable
Hi all,
I would like to estimate power and necessary sample size for a GLM with
a response variable that has a poisson distribution. Do you have any
suggestions for how I can do this in R? Thank you for your help.
Sincerely,
Craig
--
Craig A. Faulhaber
Department of Forest, Range, and Wildlife Sciences
Utah State University
5230 Old Main Hill
Logan, UT 84322
(435)797-3892
2014 Apr 13
1
[Bug 10551] New: Daemon infinite loop when no matched user in secrets
https://bugzilla.samba.org/show_bug.cgi?id=10551
Summary: Daemon infinite loop when no matched user in secrets
Product: rsync
Version: 3.1.1
Platform: x64
OS/Version: Linux
Status: NEW
Severity: major
Priority: P5
Component: core
AssignedTo: wayned at samba.org
ReportedBy: ryan at
2003 Feb 14
1
FW: [Fwd: Re: [S] Exact p-values]
Dear all
Just for fun, I have just downloaded the paper mentioned below and checked
it with R-1.6.1.
Everything is ok with exception of Table 2b, where I get always 1 instead of
0.5:
> pbinom(1e15,2e15,0.5)
[1] 1
Which value should be correct?
Best regards
Christian Stratowa
==============================================
Christian Stratowa, PhD
Boehringer Ingelheim Austria
Dept NCE Lead
2004 Aug 19
3
More precision problems in testing with Intel compilers
The Intel compiled version also fails the below test:
> ###------------ Very big and very small
> umach <- unlist(.Machine)[paste("double.x", c("min","max"), sep='')]
> xmin <- umach[1]
> xmax <- umach[2]
> tx <- unique(outer(-1:1,c(.1,1e-3,1e-7)))# 7 values (out of 9)
> tx <- unique(sort(c(outer(umach,1+tx))))# 11 values
2006 Mar 08
1
power and sample size for a GLM with Poisson response variable
Craig, Thanks for your follow-up note on using the asypow package. My
problem was not only constructing the "constraints" vector but, for my
particular situation (Poisson regression, two groups, sample sizes of
(1081,3180), I get very different results using asypow package compared
to my other (home grown) approaches.
library(asypow)
pois.mean<-c(0.0065,0.0003)
info.pois <-
2016 Dec 20
2
Very small numbers in hexadecimal notation parsed as zero
Hi all,
I have noticed incorrect parsing of very small hexadecimal numbers
like "0x1.00000000d0000p-987". Such a hexadecimal representation can
can be produced by sprintf() using the %a flag. The return value is
incorrectly reported as 0 when coercing these numbers to double using
as.double()/as.numeric(), as illustrated in the three examples below:
2003 Apr 24
2
R-1.7.0 build feedback: NetBSD 1.6 (PR#2837)
R-1.7.0 built on NetBSD 1.6, but the validation test suite failed:
Machinetype: Intel Pentium III (600 MHz); NetBSD 1.6 (GENERIC)
Remote gcc version: gcc (GCC) 3.2.2
Remote g++ version: g++ (GCC) 3.2.2
Configure environment: CC=gcc CXX=g++ LDFLAGS=-Wl,-rpath,/usr/local/lib
make[5]: Entering directory `/local/build/R-1.7.0/src/library'
>>> Building/Updating
2005 Aug 26
3
Matrix oriented computing
Hi,
I want to compute the quantiles of Chi^2 distributions with different
degrees of freedom like
x<-cbind(0.005, 0.010, 0.025, 0.05, 0.1, 0.5, 0.9, 0.95, 0.975, 0.99, 0.995)
df<-rbind(1:100)
m<-qchisq(x,df)
and hoped to get back a length(df) times length(x) matrix with the
quantiles. Since this does not work, I use
x<-c(0.005, 0.010, 0.025, 0.05, 0.1, 0.5, 0.9, 0.95, 0.975,
2010 Nov 12
1
what's wrong with this 'length' in function?
Hi all,
I am having a trouble with this function I wrote
###################################################
p26=function(x,alpha){
# dummy variable
j=1
ci=matrix(ncol=2,nrow=3)
while (j<4){
if (j==2) {x=x+c(-1,1)*0.5}
ci[j,]=
x+qnorm(1-alpha/2)^2/2+
c(-1,1)*qnorm(1-alpha/2)*
sqrt(x+qnorm(1-alpha/2)^2/4)
j=j+1
if (j==3) { # exact
x=x-c(-1,1)*0.5
2007 Oct 10
5
chi2
Hello,
I want to use the quantile function so I read the doc but I don't understand with this
> qchisq(seq(0.05,0.95,by=0.05),df=(length(don)-1))
[1] 62667.11 62795.62 62882.42 62951.47 63010.74 63064.00 63113.39 63160.27 63205.65 63250.33 63295.04 63340.48 63387.48 63437.03 63490.53 63550.14 63619.68
[18] 63707.24 63837.16
Can you help me please?