Displaying 20 results from an estimated 1000 matches similar to: "Pb with ks.test pvalue"
2005 Apr 06
1
nls.control
Hello everyone,
I'm trying to test the accurracy of R on the Eckerle4 dataset from NIST and
I don't understand how the control option of the nls function works.
I tought nls(...) was equivalent to nls(...control=nls.control()) i.e nls.control() was the default value of control, but here is the error I get :
> n2=nls(V1~(b1/b2) *
2006 Jul 09
1
KS Test Warning Message
All,
Happy World Cup and Wimbledon. This morning finds me with the first
of my many daily questions.
I am running a ks.test on residuals obtained from a regression model.
I use this code:
> ks.test(Year5.lm$residuals,pnorm)
and obtain this output
One-sample Kolmogorov-Smirnov test
data: Year5.lm$residuals
D = 0.7196, p-value < 2.2e-16
alternative hypothesis: two.sided
Warning
2005 Jun 27
1
ks.test() output interpretation
I'm using ks.test() to compare two different
measurement methods. I don't really know how to
interpret the output in the absence of critical value
table of the D statistic. I guess I could use the
p-value when available. But I also get the message
"cannot compute correct p-values with ties ..." does
it mean I can't use ks.test() for these data or I can
still use the D
2005 Mar 23
2
R accuracy
Hello,
I am trying to test the precision of R on datasets from The Statistical Reference Datasets Project http://www.itl.nist.gov/div898/strd/index.html and I don't manage to understand how R is storing its results.
For example, I calculate a mean on the michelso dataset (100 values) and find:
> m=mean(michel)
> m
V1
299.8524
> print(m,digits=15)
V1
299.8524
2005 Sep 09
2
test for exponential,lognormal and gammadistribution
hello!
i don't want to test my sample data for normality, but exponential- lognormal-
or gammadistribution.
as i've learnt the anderson-darling-test in R is only for normality and i am
not supposed to use the kolmogorov-smirnov test of R for parameter estimates
from sample data, is that true?
can you help me, how to do this anyway!
thank you very much!
nadja
2005 Jan 11
3
Kolmogorov-Smirnof test for lognormal distribution with estimated parameters
Hello all,
Would somebody be kind enough to show me how to do a KS test in R for a
lognormal distribution with ESTIMATED parameters. The R function
ks.test()says "the parameters specified must be prespecified and not
estimated from the data" Is there a way to correct this when one uses
estimated data?
Regards,
Kwabena.
--------------------------------------------
Kwabena Adusei-Poku
2007 May 02
0
KS test pvalue estimation using mctest (library truncgof)
Hi,
I'm trying to evaluate a Monte Carlo p-value (using truncgof package) on
a left truncated sample.
>From an empirical sample I've estimated a generalized pareto
distribution parameters (xi, beta, threshold) (I've used fExtremes pkg).
I'm in doubt on what of the following command is the most appropriate:
Let:
x<-sample
t<-threshold
xt<-x[x>t]
xihat<-gpdFit(x,
2006 Mar 15
2
difftime arguments
Hi
I just started using RGui.exe under widnows.
I have a text file containing date arranged in columns and rows, each column has the same format, each row with different formats. 3 of the columns are something like this 1/12/2006 3:59:45 PM
I need to calculate the different in seconds between 2 selected periods using their row’s index
My solution:
Read the file in a data frame and
2005 Jan 17
1
merge data frames taking mean/mode of multiple macthes
Hello :)
I have two data frames, one has properties taken on a
piece by piece basis and the other has performance on
a lot by lot basis. I wish to combine these two data
frames but the problem is that each lot has multiple
pieces and hence i need to take a mean of the
properties of multiple pieces and match it to the row
having data about the lot.
I was wondering if there is a simple commmand,
2006 Sep 25
1
apply: new behaviour for factors in R-2.4.0
Dear R-core
There is a different output for the apply function due to the
change of unlist as mentioned in the R news.
Newly, applying as.factor() (or factor()) in
str(dat <- data.frame(x = 1:10, f1 = gl(2,5,labels = c("A", "B"))))
(d1 <- apply(dat,2,as.factor))
newly returns a character matrix while in R-2.3.1 the same
command resulted in an integer matrix that was
2007 Jun 19
2
Preconditions for a variance analysis
Hello everbody,
i'm currently using the anova()-test for a small data.frame of 40
rows and 2 columns. It works well, but is there any preconditions for
a valid variance analysis, that i should consider?
Thank you for your answer,
Daniel
2006 Apr 25
1
summary.lme: argument "adjustSigma"
Dear R-list
I have a question concerning the argument "adjustSigma" in the
function "lme" of the package "nlme".
The help page says:
"the residual standard error is multiplied by sqrt(nobs/(nobs -
npar)), converting it to a REML-like estimate."
Having a look into the code I found:
stdFixed <- sqrt(diag(as.matrix(object$varFix)))
if (object$method
2005 May 15
3
adjusted p-values with TukeyHSD?
hi list,
i have to ask you again, having tried and searched for several days...
i want to do a TukeyHSD after an Anova, and want to get the adjusted
p-values after the Tukey Correction.
i found the p.adjust function, but it can only correct for "holm",
"hochberg", bonferroni", but not "Tukey".
Is it not possbile to get adjusted p-values after
2006 Jan 18
3
linear contrasts with anova
I have some doubts about the validity of my procedure to estimeate linear contrasts ina a factorial design.
For sake of semplicity, let's imagine a one way ANOVA with three levels. I am interested to test the significance of the difference between the first and third level (called here contrast C1) and between the first and the seconda level (called here contrast C2). I used the following
2005 Aug 02
1
plotting 3 functions on same graph
hi all,
I wish to draw on the same graphic device 3 functions.
But i don't want them to be on different graph, i want to compare them on the same
I don't need mfrow or mfcol, I need something else...
1 graph on 1 device inside this graph 3 ploted function.
I saw something unsing data.frame, but i think it's overkill, and something less complicated must exist, if not why?
why not
2005 Jan 25
1
r square values for independent variables in multiple linear regr ession model -- newbie
Hello
Could you please suggest a way to find out the r square values for each
independent variable while using "lm" for developing a multiple linear
regression model.
Thank you
avneet
"I have no data yet. It is a capital mistake to theorize before one has
data. Insensibly one begins to twist facts to suit theories instead of
theories to suit facts."
~ Sir Arthur Conan Doyle
2006 Jan 30
2
Type II SS for fixed-effect in mixed model
Hi
In mixed-model with lme()
How can I obtain Type II SS or Type III SS for fixed effect?
Thanks
Julien
2006 Feb 01
1
Randomised Block Design
Hi, I'm studying math, and i have to make an analysys using Randomised
Block Design. I have two factors, i know how to do this in Statistica, but
how to do this in R, i read some manuals but the only thing that i have
found was 2 factor ANOVA.
Please could someone help me, or give some usefull links ??
Krzytsztof Suwada
2006 Feb 20
1
Extracting variance components from lmer
Hi All.
I need a bit of help extracting the residual error variance from the VarCorr
structure from lmer.
#Here's a 2-way random effects model
lmer.1 <- lmer(rating ~ (1|person)+(1|rater), data = dat)
#Get the structure
vc.fit <- VarCorr(lmer.1)
#results in.....
$person
1 x 1 Matrix of class "dpoMatrix"
(Intercept)
(Intercept) 0.7755392
$rater
1 x 1 Matrix
2006 Sep 23
1
contrasts in aov
useRs,
A no doubt simple question, but I am baffled. Indeed, I think I
once knew the answer, but can't recover it. The default contrasts
for aov (and lm, and...) are contr.treatment and contr.poly for
unordered and ordered factors, respectively. But, how does one
invoke the latter? That is, in a data.frame, how does one indicate
that a factor is an *ordered* factor such that