Displaying 20 results from an estimated 2000 matches similar to: "survreg and pweibull"
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,
2009 Mar 09
5
Help
Hello Everyone,
I am trying to excess the inbuit .Fortran and .C codes of R. Can any one
help me in that. For example in kmeans clustering the algorithms are written
in .Fortran I want to access them and see the .Fortran syntax of the codes.
Can any one help me how can I do that?
Thanx,
Nitin Kumar
On Thu, Nov 27, 2008 at 12:00 PM, <r-help-request@r-project.org> wrote:
> Send R-help
2005 May 16
2
turning labels into a vector
Hello
1/ 'priors' is a table looking like:
"W123" "T678" "S789"
23 42 11
12 35 9
etc
2/ WBS <- labels(priors) gives me a result of class list and length 1 looking like:
"W123" "T678" "S789"
I want to read W123 into X[1] as W, T687 into X[2] as T and S789 into X[3] as S using
2008 Mar 03
1
Problem plotting curve on survival curve
Calum had a long question about drawing survival curves after fitting a Weibull
model, using pweibull, which I have not reproduced.
It is easier to get survival curves using the predict function. Here is a
simple example:
> library(survival)
> tfit <- survreg(Surv(time, status) ~ factor(ph.ecog), data=lung)
> table(lung$ph.ecog)
0 1 2 3 <NA>
63 113 50 1
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 using 1 -
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 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] NaN NaN
Warning message:
NaNs produced in: pweibull(q,
2008 Oct 31
1
loglogistic cumulative distribution used by survreg
Dear all,
What is the cumulative distribution (with parameterization) used within
survreg with respect to the log-logistic distribution?
That is, how are the parameters linked to the survivor function?
Best regards,
Mario
[[alternative HTML version deleted]]
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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r-devel mailing list -- Read
2009 Sep 08
1
Obtaining value of median survival for survfit function to use in calculation
Hi,
I'm sure this should be simple but I can't figure it out! I want to get the median survival calculated by the survfit function and use the value rather than just be able to print it. Something like this:
library(survival)
data(lung)
lung.byPS = survfit(Surv (time, status) ~ ph.ecog, data=lung)
# lung.byPS
Call: survfit(formula = Surv(time, status) ~ ph.ecog, data = lung)
1
2009 Nov 13
2
survreg function in survival package
Hi,
Is it normal to get intercept in the list of covariates in the output of survreg function with standard error, z, p.value etc? Does it mean that intercept was fitted with the covariates? Does Value column represent coefficients or some thing else?
Regards,
-------------------------------------------------
tmp = survreg(Surv(futime, fustat) ~ ecog.ps + rx, ovarian,
2020 Oct 24
3
Issue with data() function
I found an issue with the data() command this evening when working on the survival package.
1. I have a lot of data sets in the package, almost all used in at least one vignette,
help file, or test.? As a space saving measure, I have bundled many of them together,
i.e., the file data/cancer.rda contains 19 data sets, many of them small. The resulting
file (using xz compression) is quite a bit
2010 May 23
3
"order" issue
Hi everybody, this is a real dummy thing.
I sorted a matrix based on a given column, and what I get is right, until it comes to columns of negative and positive values; than, "order" orders everything from max to min in the negative values, and then AGAIN from max to min in the positive values!!!
Why isn't everything order from max to min, and that's it?
Thank you!!!
Attached
2010 Jan 29
1
help on drawing right colors within a grouped xyplot (Lattice)
Hi,
I've lost my mind on it... I have to scatterplot two vectors, grouped by a third variable, with two different dimensions according to whether each cell line in the plot is sensitive or resistant to a given drug, and with a different color for each of 9 tissues of origin.
Here's what I've done:
2010 Jul 09
4
Mysterious behavior
I had trouble with some tests for the survival suite last night that I
cannot explain.
Framework: Ubuntu Linux, R2.11.
For testing survival I have a separate directory and Makefile. I
pull everything into the local .RData, no packages, library, or
namespace. (It's easier to add test modifications to a routine in a
chain of calls).
A test of survreg + psline would fail because
2010 May 26
2
Survival analysis extrapolation
Dear all,
I'm trying to fit a curve to some 1 year failure-time data, so that I can
extrapolate and predict failure rates up to 3 years. The data is in the
general form:
Treatment Time Status
Treatment A 28 0
Treatment B 28 0
Treatment B 28 0
Treatment A 28
2004 Jan 01
1
Barplot errors in MASS script
Reading "Modern Applied Statististics with S" and trying the corresponding
examples both in the book and in ../lib/R/library/MASS/script, I'm now trying
chapter 4 plotting bars with the following code on a linux box with R 1.8.1:
----------------------
library(MASS)
library(lattice)
options(echo=T, width=65, digits=5)
lung.deaths <- aggregate(ts.union(mdeaths, fdeaths), 1)
2012 Jun 05
1
model.frame and predvars
I was looking at how the model.frame method for lm works and comparing
it to my own for coxph.
The big difference is that I try to retain xlevels and predvars
information for a new model frame, and lm does not.
I use a call to model.frame in predict.coxph, which is why I went that
route, but never noted the difference till now (preparing for my course
in Nashville).
Could someone shed light
2004 Nov 24
2
confidence interval of a average...
I have a sample of lung capacities from a population measured against
height. I need to know the 95% CI of the lung capacity of a person of
average height.
I have fitted a regression line.
How do I get a minimum and maximum values of the 95% CI?
My thinking was that this has something to do with covariance, but how?
My other thinking was that I could derive the 0.975 (sqrt 0.95) CI for the
2009 Jan 30
3
paste together object names to pass it on to a function
Hello,
I have a maybe trivial question, but I simply don't understand well
enought how to work with text/strings:
I have a rather compelx data structure, a big list with several
sub-lists/dataframes and for certain calculations (which I do in
loops), I only need a certain group of sub-lists/dataframes, which I
want to specify with a name vector and paste together the object name
and pass it