Displaying 20 results from an estimated 1000 matches similar to: "goodness-of-fit test"
2008 Feb 10
1
Error while using fitdistr() function or goodfit() function
Try changing your method to "ML" and try again. I tried the run the
first example from the documentation and it failed with the same error.
Changing the estimation method to ML worked.
@List: Can anyone else verify the error I got? I literally ran the
following two lines interactively from the example for goodfit:
dummy <- rnbinom(200, size = 1.5, prob = 0.8)
gf <- goodfit(dummy,
2009 Jul 23
1
goodfit() in vcd package: computation of chi-squared
I have troubles understanding how goodfit() function in the vcd package
computes the Pearson coefficient. Can anybody provide more information
on the computation?
In particular, for HorseKicks data in vcd package, goodfit() yields
> oo <- goodfit(HorseKicks,type="poisson",method="MinChisq")
> summary(oo)
Goodness-of-fit test for poisson distribution
2011 Aug 28
1
How to add a legend to a goodness-of-fit plot (vcd:goodfit)?
Hello,
Sample code:
library("vcd")
dummy <- rnbinom(200, size=1.5, prob=0.8)
gf <- goodfit(dummy, type="nbinomial", method="MinChisq")
plot(gf)
I would like to:
1. add a lgened stating the bars show the actual counts and the red
dots - the fit.
2. show the goodness-of-fit values calculated somewhere on an empty
white space ob the plot.
But... the legend
2010 Mar 16
2
How can I save the result for goodness of fit test
Dear All,
I run the goodness of fit test using goodfit() in vcd package.
The result is as follow:
Goodness-of-fit test for poisson distribution
X^2 df P(> X^2)
Pearson 1.053348 2 0.5905661
Warning message:
In summary.goodfit(gf) : Chi-squared approximation may be incorrect
I want to save the the test statistics(X^2), df, and p-value. How can I save
the result.
2008 Jun 30
3
Is there a good package for multiple imputation of missing values in R?
I'm looking for a package that has a start-of-the-art method of
imputation of missing values in a data frame with both continuous and
factor columns.
I've found transcan() in 'Hmisc', which appears to be possibly suited
to my needs, but I haven't been able to figure out how to get a new
data frame with the imputed values replaced (I don't have Herrell's book).
Any
2010 Oct 12
2
repeating an analysis
Hi All,
I have to say upfront that I am a complete neophyte when it comes to
programming. Nevertheless I enjoy the challenge of using R because of its
incredible statistical resources.
My problem is this .........I am running a regression tree analysis using
"rpart" and I need to run the calculation repeatedly (say n=50 times) to
obtain a distribution of results from which I will pick
2011 Jun 05
3
How to convert a factor column into a numeric one?
I have a data frame:
> head(df)
Time Temp Conc Repl Log10
1 0 -20 H 1 6.406547
2 2 -20 H 1 5.738683
3 7 -20 H 1 5.796394
4 14 -20 H 1 4.413691
5 0 4 H 1 6.406547
7 7 4 H 1 5.705433
> str(df)
'data.frame': 177 obs. of 5 variables:
$ Time : Factor w/ 4 levels
2007 May 03
4
Survival statistics--displaying multiple plots
Hello all!
I am once again analyzing patient survival data with chronic liver disease.
The severity of the liver disease is given by a number which is continuously
variable. I have referred to this number as "meld"--model for end stage
liver disease--which is the result of a mathematical calculation on
underlying laboratory values. So, for example, I can generate a Kaplan-Meier
plot
2011 Aug 10
3
plot 3d info in 2d
Hi Listers,
Is it possible to produce an ordination plot in 2d, where bubbles represent
the location of sites (this part is easy enough) and the size of the bubbles
is proportional to the sites location in 3d space (I am stuck on this
option). So sites that are very near the 2d plane of the xy axes would be
larger while sites that are actually further away in 3 d space would be
proportionally
2008 Apr 22
2
Multidimensional contingency tables
How does one ideally handle and display multidimenstional contingency
tables in R v. 2.6.2?
E.g.:
> prob1<- data.frame(victim=c(rep('white',4),rep('black',4)),
+ perp=c(rep('white',2),rep('black',2),rep('white',2),rep('black',2)),
+ death=rep(c('yes','no'),4), count=c(19,132,11,52,0,9,6,97))
> prob1
victim perp
2007 Sep 10
1
S-Plus "resample" package and associated functions
Are there any packages in R that reproduce the package "resample" of S-Plus?
The sample() function in R doesn't provide equivalent flexibility of
bootstrap() and bootstrap2().
================================================================
Robert A. LaBudde, PhD, PAS, Dpl. ACAFS e-mail: ral at lcfltd.com
Least Cost Formulations, Ltd. URL: http://lcfltd.com/
824
2008 Sep 25
1
R function which finds confidence interval for binomial variance
I need to construct confidence intervals for the binomial variance.
This is the usual estimate
v = x*(n-x)/n
or its unbiased counterpart
v' = x*(n-x)/(n-1)
where x = binomial number of successes observed in n Bernoulli trials
from proportion p.
The usual X^2 method for variance confidence intervals will not work,
because of the strong non-normal character of the sampling
2010 Jun 21
2
Singularity in simple ANCOVA problem
I'm using R 2.10.1 with the latest version of all packages (updated today).
I'm confused as to why I'm getting a hard singularity in a simple set
of experimental data:
> blots
ID Lot Age Conc
1 1 A 3 4.44
2 2 A 3 4.56
3 3 B 41 4.03
4 4 B 41 4.57
5 5 C 229 4.49
6 6 C 229 4.66
7 7 D 238 3.88
8 8 D 238 3.93
9 9 E 349 4.43
10 10 E 349
2011 Feb 09
2
comparing proportions
Hi, I have a dataset that has 2 groups of samples. For each sample, then
response measured is the number of success (no.success) obatined with the number
of trials (no.trials). So a porportion of success (prpop.success) can be
computed as no.success/no.trials. Now the objective is to test if there is a
statistical significant difference in the proportion of success between the 2
groups of
2009 Sep 03
1
Problem accessing functions in package 'roxygen'
I have Vista Home with R-2.9.0, and installed and tried to test the
package 'roxygen':
> utils:::menuInstallPkgs()
trying URL
'http://lib.stat.cmu.edu/R/CRAN/bin/windows/contrib/2.9/roxygen_0.1.zip'
Content type 'application/zip' length 699474 bytes (683 Kb)
opened URL
downloaded 683 Kb
package 'roxygen' successfully unpacked and MD5 sums checked
The
2008 Feb 13
1
Does goodfit() require frequency count of the numbers or numbers themselves?
Hello,
I am a student and for project I need R.
I have one problem regarding function goodfit().
Does goodfit() require frequency count of numbers or numbers themselves?
For example suppose I have data say 150 readings.Do I need to use goodfit()
directly on data or
should I make suitable no of bins and then apply goodfit()?
Aswad
[[alternative HTML version deleted]]
2008 Apr 10
1
Problem installing and using package "tseries"
I have R 2.6.2, and have tried downloading and installing the package
"tseries". I get the same error when I use two different mirror sites:
> utils:::menuInstallPkgs()
trying URL
'http://cran.mirrors.hoobly.com/bin/windows/contrib/2.6/tseries_0.10-14.zip'
Content type 'application/zip' length 400799 bytes (391 Kb)
opened URL
downloaded 391 Kb
package
2008 Feb 11
0
Testing for differecnes between groups, need help to find the right test in R. (Kes Knave)
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2008 Jul 12
5
shapiro wilk normality test
Hi everybody,
somehow i dont get the shapiro wilk test for normality. i just can?t
find what the H0 is .
i tried :
shapiro.test(rnorm(5000))
Shapiro-Wilk normality test
data: rnorm(5000)
W = 0.9997, p-value = 0.6205
If normality is the H0, the test says it?s probably not normal, doesn
?t it ?
5000 is the biggest n allowed by the test...
are there any other test ? ( i know qqnorm
2008 Aug 25
1
Specifying random effects distribution in glmer()
I'm trying to figure out how to carry out a Poisson regression fit to
longitudinal data with a gamma distribution with unknown shape and
scale parameters.
I've tried the 'lmer4' package's glmer() function, which fits the
Poisson regression using:
library('lme4')
fit5<- glmer(seizures ~ time + progabide + timeXprog +
offset(lnPeriod) + (1|id),
data=pdata,