Dear All.
Apologies for posting a question regarding survival analysis, and not R, to the
R-help list. In the past I received the best advices from the R community.
The random censorship model (the censoring times independent of the failure
times and vice versa) is one of the fundamental assu
Dear All,
Independent censoring is one of the fundamental assumptions in the survival
analysis. However, I cannot find any test for it or any paper which discusses
how real that assumption is.
I would be grateful if anybody could point me to some useful references. I have
found the following
Dar all,
I have a txt file with 4 column data about daily maximum temperature for
some years.
I need to find the number of heat waves and :
Average (+ standard deviation) and maximum duration of the heatwave, · The
number of heat waves, · The number of days in the summer heat wave .
txt file is
Dear all,
with the below 2 files I would like to to the t.test and var.test
but it does not work.
Can you help me ?
thanks
BR
letost_ur
19721608.3
19731825.6
19741646.8
19751718.8
19761837.5
19771905.9
19781694.6
19791928.3
19801632.6
19812064.4
1982
Dear All,
We have recently published an article on cross-validation pitfalls
http://www.jcheminf.com/content/6/1/10/
In the article, amongst other things, we discuss nested cross-validation and
variable selection with cross-validation which I am sure is of interest to
statistical modelling commu
oject.org
> From: dwinsem...@comcast.net
> To: dkrsta...@hotmail.com
> Subject: Re: [R] survival survfit with newdata
> Date: Thu, 17 May 2012 00:52:55 -0400
>
>
> On May 16, 2012, at 5:08 PM, Damjan Krstajic wrote:
>
> >
> > Dear all,
> >
> > I am confused wit
Dear all,
I am confused with the behaviour of survfit with newdata option.
I am using the latest version R-2-15-0. In the simple example below I am
building a coxph model on 90 patients and trying to predict 10 patients.
Unfortunately the survival curve at the end is for 90 patients. Could som
Dear all,
I am using glmnet + survival and due to the latest
release of glmnet
1.7.4 I was forced to use the latest version of R 2.15.0.
My previous version of R was 2.10.1. I changed glmnet version and R
version and when I started to get weird results I was not sure where the bug
was.
Dear all,
I am using glmnet (Coxnet) for building a Cox Model and
to make actual prediction, i.e. to estimate the survival function S(t,Xn) for a
new subject Xn. If I am not mistaken, glmnet (coxnet) returns beta, beta*X and
exp(beta*X), which on its own cannot generate S(t,Xn). We miss baseline
Thank you very much. I will use 1.7.1 version. Have you had time to look at
the issue regarding a weird behaviour of multinomial glmnet when alpha=0? I
posted it to r-help more than two weeks ago and maybe you missed it. Damjan
Krstajic
Subject: Re: differences between 1.7 and 1.7.1 glmnet
Dear All,
I have found differences between glmnet versions 1.7 and 1.7.1 which, in
my opinion, are not cosmetic and do not appear in the ChangeLog. If I am
not mistaken, glmnet appears to return different number of selected
input variables, i.e. nonzeroCoef(fit$beta[[1]]) differes between
ve
Dear all,
If I am not mistaken, I think that I have found a bug in glmnet 1.7.1 (latest
version) for multinomial when alpha=0. Here is the code
> library(glmnet)
Loading required package: Matrix
Loading required package: lattice
Loaded glmnet 1.7.1
> x=matrix(rnorm(40*500),40,500)
> g4=sample(1
r ridge coxph are based on published
papers.
Damjan Krstajic
> Subject: Re: [R] survival: ridge log-likelihood workaround
> From: thern...@mayo.edu
> To: r-help@r-project.org; dkrsta...@hotmail.com
> Date: Fri, 10 Dec 2010 09:07:42 -0600
>
> -- begin inclusion -
> D
Dear all,
I need to calculate likelihood ratio test for ridge regression. In February I
have reported a bug where coxph returns unpenalized log-likelihood for final
beta estimates for ridge coxph regression. In high-dimensional settings ridge
regression models usually fail for lower values of
It seems to me that summary for ridge coxph() prints summary but returns NULL.
It is not a big issue because one can calculate statistics directly from a
coxph.object. However, for some reason the score test is not calculated for
ridge coxph(), i.e score nor rscore components are not included i
kind of black box.
Any references to the literature or R packages would be very welcome.
Thanks in advance.
DK
--
Damjan Krstajic
Director
Research Centre for Cheminformatics
Belgrade, Serbia
vance.
DK
------
Damjan Krstajic
Director
Research Centre for Cheminformatics
Belgrade, Serbia
--
_
Tell us your greatest
It seems to me that R returns the unpenalized log-likelihood for the ratio
likelihood test when ridge regression Cox proportional model is implemented. Is
this as expected?
In the example below, if I am not mistaken, fit$loglik[2] is unpenalized
log-likelihood for the final estimates of coeffi
Dear all,
I will present R language and R software environment to the Statistical Society
of Serbia.
As I will doing it to professional statisticians it seems unneccesary to
me to present them how R language works in details. I am more
interested to present them with the latest facts regarding
Dear all,
Is there any R package which would help in analysing election results between
two elections? Does anybody know any good papers which are related to this
field? I am a statistician and my main research area so far has been regression
and classification modelling. The analysis of two e
Dear all,
I have encountered a weird behaviour in R
survival package which seems to me to be a bug.
The weird behaviour happens when I am using
100 variables in the ridge function when calling
coxph with following formula Surv(time = futime,
event = fustat, type = "right") ~ ridge(X1, X2,
X
ls of Statistics 10, 1100-1120
I would be really grateful if someone could help
me with the electronic copy of the paper. Writing
to the R-help emailing list was my last resort.
Thanks in advance.
With kind regards
DK
Damjan Krstajic
Director
Research Centre for Cheminform
22 matches
Mail list logo
