Displaying 20 results from an estimated 1000 matches similar to: "save p-value in mshapiro.test(mvnormtest)"
2006 Jan 12
0
question for mshapiro test
Hi,
I have a question about the p-value of mshapiro test. I simulated data
from bivariate normal 1000 times and used mshapiro test to see how many
times the test would reject the null hypothesis when the p-value is 0.05.
The answer should be around 50 since the p-value is 0.05. But I got a much
higher value. Here is the R code I used and the result.
2007 Oct 11
2
test for whether dataset comes from a known MVN
Dear all,
I have a multivariate dataset containing 100,000 or more points.
I want find the p-value for the dataset of points coming from a
particular multivariate normal distribution
With
mean vector u
Covariance matrix s2
So
H0: points ~ MVN( u, s2)
H1: points not ~ MVN( u, s2)
How do I find the p-value in R?
To me this is a likelihood ratio test problem.
In H0 the parameters are
2005 May 03
1
multivariate Shapiro Wilks test
Hello,
I have a question about multivariate Shapiro-Wilks test.
I tried to analyze if the data I have are multivariate normal, or how
far they are from being
multivariate normal. However, any time I did
>mshapiro.test(mydata)
I get the message:
Error in solve.default(R %*% t(R), tol = 1e-18) :
system is computationally singular: reciprocal condition number
= 5.38814e-021
I tried
2007 Aug 13
3
invert 160000x160000 matrix
Can R invert a 160000x160000 matrix with all positive numbers? Thanks a lot!
2007 May 07
4
Mardia's multivariate normality test
Dear all,
I got this error message
> library(dprep)
> mardia(Savg)
Error in cov(data) : 'x' is empty
But with the same data, I got
> library(mvnormtest)
> mshapiro.test(Savg)
Shapiro-Wilk normality test
data: Z
W = 0.9411, p-value = 0.6739
What does the error message "Error in cov(data) : 'x' is empty" mean? Thanks a lot!
Jiao
2006 Jun 29
0
multivariate normality test
Hello,
Could someone help me to explain the VERY big difference in applying two
tests on multivariate normality:
library(mvnormtest)
data(EuStockMarkets)
mshapiro.test(t(EuStockMarkets[15:29,1:4]))
Shapiro-Wilk normality test
data: Z
W = 0.8161, p-value = 0.005955
and
library(energy)
mvnorm.etest( EuStockMarkets[15:29,1:4] )
Energy test of multivariate normality:
2008 Jun 08
2
multinormality
is there any function under R that allows me to test the normality of my 92
sumples?
--
View this message in context: http://www.nabble.com/multinormality-tp17717230p17717230.html
Sent from the R help mailing list archive at Nabble.com.
2008 May 29
1
test for multivariate normality?
My stat textbook tells me that using Shapiro-Wilk test for each variable
one by one is not equal to a test for multivariate normality as a whole.
Does R have a function of testing for multivariate normality? Thanks.
Hongsheng (Hank) Liao, Ph.D.
Lab Manager
Center for Quantitative Fisheries Ecology
800 West 46th Street
Old Dominion University
Norfolk, Virginia 23508
Phone:757.683.4571
2007 Aug 13
1
simulate data from multivariate normal with pre-specified correlation matrix
For example, the correlation matrix is 3x3 and looks like
1 0.75 0 0 0
0.75 1 0 0 0
0 0 0 0 0
Can I write the code like this?
p<- 3 # number of variables per observation
N<- 10 # number of samples
# define population correlation matrix sigma
sigma<-matrix(0,p,p) #creates a px p matrix of 0
rank<-2
for (i in 1:rank){
for (j in 1:rank){
rho<-0.75
2009 Jun 02
1
getting elements out of list automatically
o <- (structure(list(sand.silt = structure(list(statistic =
structure(185, .Names = "W"),
parameter = NULL, p.value = 0.0478835773838087, null.value =
structure(0, .Names = "location shift"),
alternative = "two.sided", method = "Wilcoxon rank sum test with
continuity correction",
data.name = ".column by site"), .Names =
2011 Dec 15
1
printing all htest class members
Hello,
I've posted a question about this subject yesterday, but since there was no
R code to comment,
no one did.
I'm trying to have the print method for class 'htest' print some extra
information common in some test, like the time series linearity related
tests. Many of them have an 'order' parameter, representing a lag or
embedding dimension, and it would be a nice
2005 Mar 13
1
Use of htest class for different tests
Hello!
First of all I must appologize if this has been raised previously, but
search provided by Robert King at the University of Newcastle seems to
be down these days. Additionally let me know if such a question should
be sent to R-help.
I did a contribution to function hwe.hardy in package 'gap' during the
weekend. That functions performs Hardy-Weinberg equilibrium test using
MCMC. The
2004 May 20
2
Get Slot from a Class
Hello, everyone,
I don't quite understand the following message:
> TTT <- t.test(1:10, y=c(7:20))
> class(TTT)
[1] "htest"
> TTT@p.value
Error: Trying to get slot "p.value" from an object whose class ("htest") is not defined
> TTT$p.value
[1] 1.855282e-05
Why the message says the class of TTT is not defined while class(TTT) gets
2004 Mar 31
1
R-1.9.0 Beta print.power.htest problem?
Hi all,
I just used power.t.test() in Version 1.9.0 beta (2004-03-31) today
under FC1.
The following is the output:
> power.t.test(delta = .5, power = .95, type = "paired")
$n
[1] 53.94062
$delta
[1] 0.5
$sd
[1] 1
$sig.level
[1] 0.05
$power
[1] 0.95
$alternative
[1] "two.sided"
$note
[1] "n is number of *pairs*, sd is std.dev. of *differences* within
2008 Jan 09
3
likelihood from test result
Is there any automatic mechanism for extracting a likelihood or test
statistic distribution (PDF or CDF) from an object of class "htest" or
from another object of a general class encoding a hypothesis test
result?
I would like to have a function that takes "x", an object of class
"htest", as its only argument and that returns the likelihood or test
statistic
2012 Mar 28
2
Test Normality
Good Night
I made different test to check normality and multinormality in my dataset,
but I donĀ“t know which test is better.
To verify univariate normality I checked: shapiro.test, cvm.test, ad.test,
lillie.test, sf.test or jaque.bera.test and
To verify multivariate normal distribution I use mardia, mvShapiro.Test,
mvsf, mshapiro.test, mvnorm.e.
I have a dataset with almost 1000 data and 9
2011 Jun 20
1
requesting a mentor for R development
I'd like to learn the process of revising R functions & packages and
then submitting proposed patches to the R Core team. Would someone be
willing to mentor me through one example?
For starters, consider an example. I'd like to revise the t.test
function to return the stderr value to the user. We only need to
change the "rval" in the third-from-the end line of
2011 Oct 03
2
extracting p-values in scientific notation
Dear all
How does print.htest display the p-value in scientific notation?
> (x <- cor.test(iris[[1]], iris[[3]]))
Pearson's product-moment correlation
data: iris[[1]] and iris[[3]]
t = 21.65, df = 148, p-value < 2.2e-16
alternative hypothesis: true correlation is not equal to 0
95 percent confidence interval:
0.8270 0.9055
sample estimates:
cor
0.8718
Above the p-value comes
1997 Aug 21
2
R-alpha: new class for chisquare tests?
I sort of asked this before, but perhaps not explicitly enough.
In my ctest collection, there are several chisquare-based tests. For
some of them, it may be useful to also return information on expected
(and observed) counts. The question is, how should this be done. Of
course, there is no problem adding the corresponding components to the
list returned by the functions. However, as these are
2008 Oct 16
2
Saving results of Kruskal Walis test
Hello,
I am running Kruskal-Walis test in R. When I try to save results using
write.table it gives me the following error :
Error in as.data.frame.default(x[[i]], optional = TRUE, stringsAsFactors =
stringsAsFactors) :
cannot coerce class "htest" into a data.frame
The overall code is as follows :
>data_file = read.table("~/DATA.dir/data_file.txt", header=T)