Displaying 20 results from an estimated 2000 matches similar to: "Hartigan's Dip test"
2004 Oct 22
1
p-values for the dip test
Hi all,
I am using Hartigan & Hartigan's [1] "dip test" of unimodality via the
diptest package in R. The function dip() returns the value of the test
statistic but I am having problems calculating the p-value associated with
that value. I'm hoping someone here is familiar with this process and can
explain it.
In the original article there is an example using n=63 and a
2011 Dec 21
1
Diptest- I'm getting significant values when I shouldn't?
>From library(diptest):
Shouldn't the following almost always be non-significant for
Hartigan's dip test?
dip(x = rnorm(1000))
I get dip scores of around 0.0008 which based on p values taken from
the table (at N=1000), using the command: qDiptab, are 0.02 < p <
0.05.
Anyone familiar with Hartigan's dip test and what I may not be
understanding?
Thanks,
kbrownk
2012 Nov 09
1
Duda sobre modas en un distribución
Hola a tod en s, estoy intentando averiguar el número de modas en una
distribución. Para ello utilizo diptest. Mi duda es que no acabo de
entender cuando la información suministrada por los test suponen la
existencia o no de unimodalidad/multimodalidad. Una parte de la salidad de
diptest es la que pego a continuación (el resto esta en el fichero adjunto
con las distribuciones kernels y las
2009 Feb 03
1
testing for bimodal distribution
I'm not sure where to begin with this, but I was wondering if someone could
refer me to an R package that would test to see if a distribution fits a
bimodal distribution better than a unimodal distribution.
Thanks,
Andrew
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2009 Aug 30
3
test for bimodality&In-Reply-To=
Has a test for bimodality been implemented in R?
Thanks, John
NIWA is the trading name of the National Institute of Water & Atmospheric Research Ltd.
2009 May 13
1
High Volume US Traffic? Claim DIP Compensation!
This could be a nice opportunity for users with a high volume of SIP traffic
terminating in the US:
Collecting dip fees on outbound phone calls - fees that would otherwise go
to the local phone company.
With all the recent fees and surcharges, the cost of wholesale telecom and
dialer traffic keeps rising. But what many companies with a high volume of
IP based voice traffic don't realize
1997 Apr 29
9
Yet Another DIP Exploit?
I seem to have stumbled across another vulnerability in DIP. It
appears to allow any user to gain control of arbitrary devices in /dev.
For instance, I have successfully stolen keystrokes from a root login as
follows... (I could also dump characters to the root console)
$ whoami
cesaro
$ cat < /dev/tty1 <------ root login here
bash: /dev/tty1: Permission denied
2008 Sep 09
3
Modality Test
Dear Readers:
I have two issues in nonparametric statistical analysis that i need
help:
First, does R have a package that can implement the multimodality test,
e.g., the Silverman test, DIP test, MAP test or Runt test. I have seen
an earlier thread (sometime in 2003) where someone was trying to write
a code for the Silverman test of multimodality. Is there any other
tests that can enable me to
2004 Oct 04
3
Help with normal distributions
Hi
I have two questions, the first perhaps dumber than the second.
Firstly, I have a data set, and when I plot a histogram it looks like a
normal distribution. So I want to overlay a bell-shaped normal
distribution on top of it, to demonstrate how similar it is to the
normal distribution. I have read the help on dnorm(), rnorm(), pnorm()
etc but still can't figure out how to plot a normal
2008 Jun 13
3
cluster.stats
Dear list,
I just tried to use the function cluster.stat in the package fpc.
I just have a couple of questions about the syntax:
cluster.stats(d,clustering,alt.clustering=NULL,
silhouette=TRUE,G2=FALSE,G3=FALSE)
1) the distance object (d) is an object obtained by the function dist() on
my own original matrix?
2) clustering is the clusters vector as result of one of the many clustering
methods?
2005 Sep 29
5
Regression slope confidence interval
Hi list,
is there any direct way to obtain confidence intervals for the regression
slope from lm, predict.lm or the like?
(If not, is there any reason? This is also missing in some other statistics
softwares, and I thought this would be quite a standard application.)
I know that it's easy to implement but it's for
explanation to people who faint if they have to do their own
programming...
2009 May 07
2
Linear least squares fit with errors in both x and y values.
HI,
I'd like to perform a weighted linear least squares fit with R on data
with varying errors on both vectors. I can do this with one axis using
lm, but have no idea where to go from here. I've tried googling, but no
idea. Any suggestions?
Thanks,
James
2003 Jul 11
1
unimodality test
Dear R users,
I am interested in uni- bi- multimodality tests, for analysing reaction
times data. I was lead to Hartigan's dip test (Ann. Statistics, 13, 1985,
pp. 70-84, Applied Statistics, 34, 1985, 320-325). Not being a programmer
I am unable to translate the Fortran code given in ref. 2 into a R
function. I'd be glad to learn that someone already did it, or has devised
a better
2009 Jul 17
2
Fisher's exact test
Hi,
I'm trying to run Fisher's Exact test on the data below, but I'm not
sure how interpret the data shown. Can someone tell me what this is
saying? Looking at the numbers it should be that there's no significant
difference between the HDL and LDL, but a p-value of 1 seems high. Is
the low value in the LDL unbound making the test unstable and should I
be using an alternative?
Best
2006 Dec 05
0
Jumpers and DIP switches on Atcom AX-4S and AX-1E
Hello all !
Does anyone have a document describing jumpers, DIP switches, and connectors
on Atcom's AX-4S (HFC-4S based 4xBRI) and AX-1E (HFC-1E based 1xPRI) cards
? Got the cards without any documents, there is nothing on a subject on
Atcom's site, and so far no one from their support is replying to my emails.
Thanks very much.
Cheers,
Nenad
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2005 Aug 08
2
selecting outliers
Hi everybody,
I'd like to know if there's an easy way for extracting
outliers record from a dataset, in order to perform
further analysis on them.
Thanks
Alessandro
2009 Dec 11
1
cluster size
hi r-help,
i am doing kmeans clustering in stats. i tried for five clusters clustering using:
kcl1 <- kmeans(as1[,c("contlife","somlife","agglife","sexlife",
"rellife","hordlife","doutlife","symtlife","washlife",
2010 Apr 24
4
DICE Coefficient of similarity measure
Hi,
I wanted the DICE coefficient (similarity measure for binary variables)
to be calculated in R and found that the "igraph" package has the option
of "similarity.dice" to do this. But, for this command, the input object
should be an igraph object. But, I have a dataframe of columns
containing 1's and 0's. Can I convert this dataframe into an igraph
object, so that
2005 Aug 08
2
computationally singular
Hi,
I have a dataset which has around 138 variables and 30,000 cases. I am
trying to calculate a mahalanobis distance matrix for them and my
procedure is like this:
Suppose my data is stored in mymatrix
> S<-cov(mymatrix) # this is fine
> D<-sapply(1:nrow(mymatrix), function(i) mahalanobis(mymatrix, mymatrix[i,], S))
Error in solve.default(cov, ...) : system is computationally
2011 Jun 09
1
k-nn hierarchical clustering
Hi there,
is there any R-function for k-nearest neighbour agglomerative hierarchical
clustering?
By this I mean standard agglomerative hierarchical clustering as in hclust
or agnes, but with the k-nearest neighbour distance between clusters used
on the higher levels where there are at least k>1 distances between two
clusters (single linkage is 1-nearest neighbour clustering)?
Best regards,