Displaying 20 results from an estimated 2000 matches similar to: "Estimating Weibull Distribution Parameters - very basic question"
2001 Feb 08
2
Test for multiple contrasts?
Hello,
I've fitted a parametric survival model by
> survreg(Surv(Week, Cens) ~ C(Treatment, srmod.contr),
> data = poll.surv.wo3)
where srmod.contr is the following matrix of contrasts:
prep auto poll self home
[1,] 1 1 1.0000000 0.0 0
[2,] -1 0 0.0000000 0.0 0
[3,] 0 -1 0.0000000 0.0 0
[4,] 0 0 -0.3333333 1.0 0
[5,] 0 0
2001 Sep 27
1
list of all objects - just being curious
Hello all,
to obtain a list of all objects in all search paths, I've found the
following to work:
> biglist <- sapply(1:length(search()), objects)
This more obvious one, however, does not work:
> biglist <- sapply(search(), objects)
Error in pos.to.env(pos) : invalid argument
Still, search() gives
[1] ".GlobalEnv" "package:ctest" "Autoloads"
2002 Apr 04
1
html documentation bug in: help(par), 'las'
Currently (R-1.4.1 as well as R-devel, according to
http://stat.ethz.ch/R-alpha/R-devel/library/base/html/par.html), the html
version of help(par) shows
[...]
lab
A numerical vector of the form c(x, y, len) which modifies the way that
axes are annotated. The values of x and y give the (approximate) number
of tickmarks on the x and y axes and len specifies the label size. The
default
2012 Feb 21
3
HELP ERROR Weibull values must be > 0
GUYS,
I NEED HELP WITH ERROR:
library(MASS)
> dados<-read.table("mediaRGinverno.txt",header=FALSE)
> vento50<-fitdistr(dados[[1]],densfun="weibull")
Erro em fitdistr(dados[[1]], densfun = "weibull") :
Weibull values must be > 0
WHY RETURN THIS ERROR? WHAT CAN I DO?
BEST REGARDS
[[alternative HTML version deleted]]
2001 Dec 19
2
How to create a data.frame "like" another, but longer?
Hello,
does anyone know of a quick way to create a data frame "like" another, but
with more rows?
What I'd like to do is this:
if mydata is a data.frame like
a b c
1 TRUE yes
2 FALSE no
3 TRUE yes
I'd like to get mydata2 with the same column names and column types, but
without the values and with more rows.
All I could think of was to manually do
2000 May 09
1
Type III Sums of Squares?
Hello,
I'd like to propose an extension to the function summary.aov.
In Splus (2000, I don't know about other versions), summary.aov allows a
parameter ssType to be set to 1 or 3 (defaults to 1) to choose the type of
Sums of Squares.
I know I can get Type III SS in R with drop1(model), but including the
functionality into summary.aov would, in my opinion,
- yield a more usable table
2000 Jun 22
1
R 1.1 congrat; undocumented behaviour of recordPlot
Hello,
first, I'd like to congratulate the core team to the new R version 1.1. I
think it's a great update, with glimpses into an even greater future
(tcltk!).
While playing around with the new functions (on Win 95), I found the
following:
As the documentation states, when I generate a plot and save it with
recordPlot, I can regenerate it by printing the variable:
> plot(1:10)
>
2000 Jun 23
1
Re: undocumented behaviour of recordPlot (PR#578)
On Thu, Jun 22, 2000 at 05:01:32PM +0200, p.dalgaard@biostat.ku.dk wrote:
> I think this is pretty certainly a bug, so I'm cc'ing this to r-bugs.
>
> -p
>
> Kaspar Pflugshaupt <pflugshaupt@geobot.umnw.ethz.ch> writes:
> > As the documentation states, when I generate a plot and save it with
> > recordPlot, I can regenerate it by printing the variable:
2000 Jun 23
1
Re: undocumented behaviour of recordPlot (PR#578)
On Thu, Jun 22, 2000 at 05:01:32PM +0200, p.dalgaard@biostat.ku.dk wrote:
> I think this is pretty certainly a bug, so I'm cc'ing this to r-bugs.
>
> -p
>
> Kaspar Pflugshaupt <pflugshaupt@geobot.umnw.ethz.ch> writes:
> > As the documentation states, when I generate a plot and save it with
> > recordPlot, I can regenerate it by printing the variable:
2000 Mar 22
4
density ellipses?
Hello,
has anybody written a function to plot density ellipses (95%, 99% or
anything) in a scatterplot? I found nothing in any package, nor in the list
archives.
There does seem to be a contributed package "ellipse" for S-Plus (on
S-Archive), but it does a lot more than what I would need. Still, if anybody
ported it to R, I'd be grateful for a link. I'm a bit afraid to try the
2002 Jan 31
1
MacOS X: Packages KernSmooth and cluster won't compile
Hello,
I'm using R 1.40 on MacOS X X.1.2 (installed via the fink package manager).
To upgrade my installed packages, I tried to use update.packages() today.
All went well for most packages, with the exception of KernSmooth and
cluster. In both cases, libraries were not found although I think they are
present.
Here's what happened:
----------------------------------
>
2009 Apr 30
1
finite mixture model (2-component Weibull): plotting Weibull components?
Dear Knowledgeable R Community Members,
Please excuse my ignorance, I apologize in advance if this is an easy question, but I am a bit stumped and could use a little guidance.
I have a finite mixture modeling problem -- for example, a 2-component Weibull mixture -- where the components have a large overlap, and
I am trying to adapt the "mclust" package which concern to normal
2002 Feb 04
1
Installing contributed packages on MacOS X: Solved!
I had run into problems when compiling some contributed packages to an
installation of R 1.40 by fink on MacOS X. Namely, packages KernSmooth
(2.22-7) and cluster (1.4-0) would not find required libraries, though those
were present on the system.
Jeff Whitaker, the maintainer of the R fink packages, kindly sent me this:
> Kaspar: It's not looking in /sw/lib, where the libs are (the
2002 Apr 05
2
weighted 2 or 3 parameter weibull estimation?
I've figured out how to use optim (barely) to estimate 2 parameter =
weibull distributions. I can't get over how easy this is. What I need to =
do is use a weight in the observations.....
For example,=20
the tree diameters and weights are are=20
4.70 , 100
6.00, 98
7.10, 75.0
8.10, 86.3
8.60, 80.456
8.90, 20.5
9.50, 16.6
11.40, 12.657
11.80, 12.47
14.50,
2003 Oct 20
1
Fitting a Weibull/NaNs
I'm trying to fit a Weibull distribution to some data via maximum
likelihood estimation. I'm following the procedure described by Doug
Bates in his "Using Open Source Software to Teach Mathematical
Statistics" but I keep getting warnings about NaNs being converted to
maximum positive value:
> llfunc <- function (x) { -sum(dweibull(AM,shape=x[1],scale=x[2], log=TRUE))}
>
2008 Apr 15
1
Weibull
Dear R users,
This is a basic question.
I want to fit a Weibull distribution. fitdistr(data, "weibull") works and it
is a maximum likelihood fitting. Is it a good method ? Or is it better to
write a function for the log-likelihood and the gradient and to use a
numerical routine ?
Fitdistr works for uncensored data, but what can I use for censored (and
uncensored) data ?
Thank you
2000 Oct 21
1
scale() and NA values
Hello,
I've a question concerning the behaviour of the "scale" function in the base
package. I'm using R 1.1.1 on Windows 95.
If I take a matrix with NA values, such as
> tm <- matrix(c(2,1,0,1,0,NA,NA,NA,0), nrow=3)
> tm
[,1] [,2] [,3]
[1,] 2 1 NA
[2,] 1 0 NA
[3,] 0 NA 0
and scale it, the columns containing NAs come out all NA:
>
2001 Mar 21
5
generate random number
Hi,
I want to pick 3 "integer" random numbers from 1 to
10. How to do this?
Thanks,
Yu-Ling Wu
__________________________________________________
Do You Yahoo!?
Get email at your own domain with Yahoo! Mail.
http://personal.mail.yahoo.com/
-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-
r-help mailing list -- Read
2002 Jan 17
1
weibull in R
Hi all
I try to make a weibull survival analysis on R.
I know make this on GLIM, and now I try to make the GLIM exercice GLEX8 on R
to learning and compare the test.
The variables are:
time censor group bodymass
In GLIM I make:
$calc %s=1 $ to fit weibull rather than exponential
$input %pcl weibull $
$macro model group*bodymass $endmac$
$use weibull t w %s $
Then, GLIM estimate an alpha for the
2011 Oct 28
1
weibull fitdistr problem: optimization failed
I'm getting errors when running what seems to be a simple Weibull
distribution function:
This works:
x <-
c(23,19,37,38,40,36,172,48,113,90,54,104,90,54,157,51,77,78,144,34,29,45,16,15,37,218,170,44,121)
rate <- c(.01,.02,.04,.05,.1,.2,.3,.4,.5,.8,.9)
year <- c(100,50,25,20,10,5,3.3,2.5,2,1.2,1.1)
library(MASS)
x <- sort(x)
tryCatch(
f<-fitdistr(x, 'weibull'),
error