Displaying 20 results from an estimated 62 matches for "pweibul".
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pweibull
2002 May 11
4
Is this a bug of pweibull()?
In rw1050, I found that
> pweibull(3:10, 2)
[1] 0.9998766 0.9999999 1.0000000 1.0000000 NaN NaN
[7] NaN NaN
Warning message:
NaNs produced in: pweibull(q, shape, scale, lower.tail, log.p)
more surprisingly,
> pweibull(3:10, 2.1)
[1] 0.9999566 1.0000000 1.0000000 -Inf NaN NaN
[7]...
2008 Feb 08
2
Catching NaNs from pweibull()
Hello,
I am working with the nls() function and inserting a formula into it that
uses the pweibull function. However the pweibull function is annoyingly
producing NaNs, which nls() refuses to handle. I have put a sample of the
code below. Is there a way to prevent these NaNs from interfering, for
example a method to catch them? I get the following error when I try to run
the code:
res.nls <...
2002 May 12
2
Is this a bug of pweibull()? (Follow up)
Please allow me to add just a little more about this:
nothing wrong with pweibull(), namely, the two cases I reported:
pweibull(3:10, 2) and pweibull(3:10, 2.1),
in rw1041 and earlier version.
I wonder this might just due to the change from rw1041 to rw1050,
however, I can't find anything relevant (seems to me) in the News
or Readme.
Thanks Sundar for the suggestion of us...
2013 Mar 03
1
distribution functions and lists
Hello everyone,
I have a quick question but I am stuck with it and I do not know how to solve it.
Imagine I need the distribution function of a Weibull(1,1) at t=3, then I will write pweibull(3,1,1).
I want to keep the shape and scale parameters in a list (or a vector or whatever). Then I have
parameters<-list(shape=1,scale=1)
but when I write pweibull(3,parameters) I get the following error:
Error in pweibull(q, shape, scale, lower.tail, log.p) :
Non-numeric argument to mathem...
2008 Nov 26
1
survreg and pweibull
Dear all -
I have followed the thread the reply to which was lead by Thomas
Lumley about using pweibull to generate fitted survival curves for
survreg models.
http://tolstoy.newcastle.edu.au/R/help/04/11/7766.html
Using the lung data set,
data(lung)
lung.wbs <- survreg( Surv(time, status)~ 1, data=lung, dist='weibull')
curve(pweibull(x, scale=exp(coef(lung.wbs)), shape=1/lung.wbs
$s...
2002 Feb 28
1
pweibull.c (PR#1334)
Full_Name: M Welinder
Version: 1.4
OS: (src)
Submission from: (NULL) (192.5.35.38)
It seems to me that pweibull can be improved in the lower_tail=TRUE and
log_p=FALSE
case by using expm1. Something like
-expm1(-pow(x / scale, shape)),
I think.
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Send...
2010 May 26
2
Survival analysis extrapolation
...to 360, 0 represents a withdrawal and 1
represents a failure. The code I've tried is as follows:
survdata<-read.csv("Data.csv")
WeiModel<-survreg(Surv(survdata$Time,survdata$Status)~survdata$Treatment)
summary(WeiModel)
n<-seq(0, 1080, 30 )
##Compute Weibull CDF
A<-pweibull(n, scale=exp(WeiModel$coef[1]), shape=1/WeiModel$scale)
B<-pweibull(n,
scale=exp(WeiModel$coef[1]+WeiModel$coef[2]),shape=1/WeiModel$scale)
##Transform into survivor function
ACurv<-1-A
BCurv<-1-B
The problem is, that the Weibull curve is predicting a survival probability
for treatme...
2003 May 04
0
R-1.7.0 build feedback: NetBSD 1.6 (PR#2837): final report
...in/R, it works, and passes all but the base-Ex
test.
Brian Ripley responds to the reg-tests-1.Rout.fail file found in the
working build:
>> ...
>> The error will be in the last command line, so
>> only the last few lines of the file are relevant: to wit
>>
>> > ## pweibull(large, log=T):
>> > stopifnot(pweibull(seq(1,50,len=1001), 2,3, log = TRUE) < 0)
>> Error: pweibull(seq(1, 50, len = 1001), 2, 3, log = TRUE) < 0 is not TRUE
>>
>> for which you would need to investigate the output of
>>
>> pweibull(seq(1, 50, len = 100...
2011 Oct 20
1
R code Error : Hybrid Censored Weibull Distribution
...t. I'm sending the code :
#########################################################################################
f3<-function(t,r){
#calculation for t1
fb1<-function(t,r){
v1<-numeric(0)
for(j in 1:r){
int1<-function(x1){
int_1<- (1/p+log(x1/lamda))^2 * j * choose(n,j) *
(pweibull(x1,shape=p,scale=lamda))^(j-1) * (1 -
pweibull(x1,shape=p,scale=lamda))^(n-j) *
dweibull(x1,shape=p,scale=lamda)
int_1
}
v1[j]<-integrate(int1,lower=0,upper=t)$value
}
sum(v1)
}
#calculation for t2
fb2<-function(t,r){
v2<-numeric(0)
for(j in 1:r){
int2<-function(x2){
int_2<- (1/p...
2011 Jun 23
2
Confidence interval from resampling
...;weibull")
x.wei
shape scale
6.7291685 5.3769965
(0.7807718) (0.1254696)
xwei.shape <- x.wei$estimate[[1]]
xwei.scale <- x.wei$estimate[[2]]
x.wei<-fitdistr(x,"weibull")
x.wei
xwei.shape <- x.wei$estimate[[1]]
xwei.scale <- x.wei$estimate[[2]]
curve(pweibull(x, shape=xwei.shape, scale = xwei.scale,lower.tail=TRUE,
log.p=FALSE), add=TRUE,col='green',lwd=3)
#draw random numbers from a weibull distribution 100 times with
shape=xwei.shape, scale = xwei.scale
draw <- lapply(1:100, function(.x){
out<-rweibull(x, shape=xwei.shape, scale = xwei...
2004 Apr 22
1
slower execution in R 1.9.0
...perations under 1.9.0
self.time self.pct total.time total.pct
$<-.data.frame 110.64 93.3 110.68 93.3
FMD 5.38 4.5 118.60 100.0
DIRinf 0.54 0.5 11.82 10.0
INDinf 0.46 0.4 9.78 8.2
pweibull 0.38 0.3 0.38 0.3
top 5 operations under 1.7.1
self.time self.pct total.time total.pct
pweibull 2.62 55.7 2.62 55.7
^ 0.76 16.2 0.76 16.2
CalcDistance 0.1...
2008 Mar 02
1
Problem plotting curve on survival curve (something silly?)
...very nice so far. The I followed bits and pieces of
other peoples posts in the past to plot on a weibull regression...
> my_curve.Plac <- survreg( Surv(Survival, Censored==0)~
TreatmentGroup, subset=TreatmentGroup=="Placebo", data=TestData,
dist='weibull')
> curve(pweibull(x, scale=exp(coef(my_curve.Plac)),
shape=1/my_curve.Plac$scale, lower.tail=FALSE),from=0, col="black",
to=max(TestData$Survival), add=TRUE)
> my_curve.Pred <- survreg( Surv(Survival, Censored==0)~
TreatmentGroup, subset=TreatmentGroup=="Prednisolone", data=TestData,...
2004 Nov 23
6
Weibull survival regression
Dear R users,
Please can you help me with a relatively straightforward problem that I
am struggling with? I am simply trying to plot a baseline survivor and
hazard function for a simple data set of lung cancer survival where
`futime' is follow up time in months and status is 1=dead and 0=alive.
Using the survival package:
lung.wbs <- survreg( Surv(futime, status)~ 1, data=lung,
2008 Aug 21
1
pnmath compilation failure; dylib issue?
...2.o ftrunc.o gamma.o
gamma_cody.o i1mach.o imax2.o imin2.o lbeta.o lgamma.o lgammacor.o
mlutils.o pbeta.o pbinom.o pcauchy.o pchisq.o pexp.o pf.o pgamma.o
pgeom.o phyper.o plnorm.o plogis.o pnbeta.o pnbinom.o pnchisq.o pnf.o
pnmath.o pnorm.o pnt.o polygamma.o ppois.o pt.o ptukey.o punif.o
pweibull.o qbeta.o qbinom.o qcauchy.o qchisq.o qexp.o qf.o qgamma.o
qgeom.o qhyper.o qlnorm.o qlogis.o qnbeta.o qnbinom.o qnchisq.o qnf.o
qnorm.o qnt.o qpois.o qt.o qtukey.o qunif.o qweibull.o sign.o
stirlerr.o toms708.o -lgomp -F/Library/Frameworks/R.framework/.. -
framework R -Wl,-framework -Wl,C...
2006 Nov 11
1
Fitting a survival curve
I am new to R and am trying to fit a survival curve with a weibull
hazard function to a set of data giving the probability of survival to
age x, given the year of birth, in the form:
Probability of survival:
Birth year
1980 1981 ... 2003
.2 0.90 0.89 ... 0.87
1 0.80 0.81 ... 0.79
age 2 0.75 0.74 ... 0.73
3 0.70 0.69 ... 0.68
5 0.50 0.49 ... 0.43
10 0.30 0.31 ... 0.26
I would like to be
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
2010 Mar 01
1
Fitting chi-squared distribution
Dear all,
I have a question regarding performing test if the data fits chi-squared
distribution.
For example, using ks.test()
I found in the examples how to fit it to gamma or weibull
x<-rnorm(100)
ks.test(x, "pweibull", shape=2,scale=1)
for the gamma, pgamma can be used
But I cannot find the value of this second parameter for the chi-squared
distribution.
Maybe someone experienced the similar problem?
Thanks a lot!
[[alternative HTML version deleted]]
2012 Jan 04
1
KS and AD test for Generalized PAreto and Generalized Extreme value
Dear R helpers,
I need to use KS and AD test for Generalized Pareto and Generalized extreme value.
E.g. if I need to use KS for Weibull, I have teh syntax
ks.test(x.wei,"pweibull", shape=2,scale=1)
Similarly, for AD I use
ad.test(x, distr.fun, ...)
My problem is fir given data, I have estimated the parameters of GPD and GEV using lmom. But I am not able to find out the distribution name I should be use for these distributions if I wish to use these tests.
E.g, fo...
2010 Sep 21
2
Survival curve mean adjusted for covariate: NEED TO DO IN NEXT 2 HOURS, PLEASE HELP
...fit to
a data set, adjusted for a categorical covariate , gender (0=male,1=female).
Here is my code:
library(survival)
survdata<-read.csv("data.csv")
##Fit Weibull model to data
WeiModel<-survreg(Surv(survdata$Time,survdata$Status)~survdata$gender)
summary(WeiModel)
P<-pweibull(n, scale=exp(WeiModel$coef[1]), shape=1/WeiModel$scale)
##Return mean
scale<-exp(WeiModel$coef[1])
shape<-1/WeiModel$scale
mean <- scale*gamma(1+1/shape)
mean
The problem is that the mean is based on the baseline coefficient which
assumes the population is male (= 0). I want an...
1999 Dec 09
1
nlm() problem or MLE problem?
...rt/data2/triam1.dat")
rt<-sort(rt)
plot(rt,ppoints(rt))
a<-9
b<-.27
fn<-function(p) -sum( log(dweibull(rt,p[1],p[2])) )
cat("starting -log like=",fn(c(a,b)),"\n")
out<-nlm(fn,p=c(a,b), hessian=TRUE)
xfit<-seq(min(rt),max(rt),(max(rt)-min(rt))/100)
yfit<-pweibull(xfit,out$estimate[1], out$estimate[2])
lines(xfit,yfit,lty=2)
yfit2<-pweibull(xfit,a, b)
lines(xfit,yfit2)
list(out=out)
}
I got the starting values a=9, b=.27 from fitting the Weibull CDF by eye
to a quantile plot of the data. The final values fitted by nlm() are a=
4.8299357, b= 0.2753897
I...