Displaying 9 results from an estimated 9 matches for "cox1".
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com1
2004 Aug 25
1
brlr function
Hi,
I'm trying the brlr function in a penalized logistic regression function.
However, I am not sure why I am encountering errors. I hope to seek
your advice here. (output below)
Thank you! Your help is truly appreciated.
Min-Han
#No error here, the glm seems to work fine
> genes.cox1.glm1<-glm(as.formula(paste(paste('as.integer(sim.cv.cox.yhat1)~'),paste('sim.dat.tst[',genes.cox1.rows,',]',sep="",collapse='+'))))
#Something happened here ... I only substituted brlr for glm
> genes.cox1.glm1<-brlr(as.formula(paste(paste('a...
2011 Sep 17
0
Warning in 'probtrans'-function ('mstate'-package)
..."t2", "t2"),
status = c(NA, "s0", "s1", "s2"),
data= S1, trans=tmat, keep=covs)
# add 'transition-specific' covariates
SLV <- expand.covs(SL, covs, append=TRUE, longnames=TRUE)
head(SLV)
names(SLV)
# fit stratified Markov model
cox1 <- coxph(Surv(Tstart, Tstop, status) ~
(v1.1 + v2.1) * v3.1 +
(v1.2 + v2.2) * v3.2 +
(v1.3 + v2.3) * v3.3 +
strata(trans), SLV,
method = "breslow")
summary(cox1)
# 'cloned' data for making predictions: specific covariate 'v3' fixed
at 0 (& 1):
SLV0 <- SLV[1:...
2011 Nov 23
1
Measure of separation for survival data
...mal() is the inverse normal distribution function, and where n is the sample size and _pi = 3.141592654 ...
4. In case of ties in the original xb, substitute average zi's over each of the tied sets.
5. Perform regression (e.g. Cox) on z = z1,...,zn.
I can obviously do steps 1 and 2:
# step 1 #
cox1 <- cph(Surv(stime1,eind1)~adat1+bdat1+c11+c21)
c1dat <- cox1$linear.predictors
# step 2 #
ris <- rank(c1dat,ties.method="minimum")
Can anyone advise how I might invoke the inverse normal. I thought 'qnorm' may be an option but I'm lacking the necessary parameters wi...
2004 Jul 26
5
covariate selection in cox model (counting process)
Hello everyone,
I am searching for a covariate selection procedure in a cox model formulated
as a counting process.
I use intervals, my formula looks like coxph(Surv(start,stop,status)~
x1+x2+...+cluster(id),robust=T) where id is a country code (I study
occurence of civil wars from 1962 to 1997).
I'd like something not based on p-values, since they have several flaws for
this purpose.
I turned
2013 Apr 16
1
assistant
Dear Sir/Ma,
I Adelabu.A.A, one of the R-users from Nigeria. When am running a coxph command the below error was generated, and have try some idea but not going through. kindly please assist:
> cox1 <- coxph(Surv(tmonth,status) ~ sex + age + marital + sumassure, X)
Warning message:
In fitter(X, Y, strats, offset, init, control, weights = weights, :
Ran out of iterations and did not converge
> summary(cox1, conf.int=0.95, exact = TRUE)
Call:
coxph(formula = Surv(tmonth, status) ~...
2005 Apr 06
0
Version 0.93 of GAM package on CRAN
...ion 0.92 have been fixed; notably
1) some problems with predict and newdata
2) plot.gam now works with any model for which predict( ...,
type="terms") is appropriate
(well, at least several). Examples are lm, glm, gam and coxph models.
So for example, if you have fit a Cox model
cox1 <- coxph( Surv(Survival, death) ~ Grade + ns(Age,4) + ns(Size,4))
Then plot.gam(cox1, se=T) will produce three plots, one for each term
in the model, with standard error bands.
3) I have implemented the fast versions of backfitting for models
consisting of all local regression
terms (...
2005 Apr 06
0
Version 0.93 of GAM package on CRAN
...ion 0.92 have been fixed; notably
1) some problems with predict and newdata
2) plot.gam now works with any model for which predict( ...,
type="terms") is appropriate
(well, at least several). Examples are lm, glm, gam and coxph models.
So for example, if you have fit a Cox model
cox1 <- coxph( Surv(Survival, death) ~ Grade + ns(Age,4) + ns(Size,4))
Then plot.gam(cox1, se=T) will produce three plots, one for each term
in the model, with standard error bands.
3) I have implemented the fast versions of backfitting for models
consisting of all local regression
terms (...
2008 Jan 16
1
exact method in coxph
...1 4 4 2 1 1 45.48
2 0 1 0 0 0 14.84
2 1 2 0 1 1 08.63
A complication here is that units can experience repeated events while
previous events are still ongoing.
I tried the following: cox1 <- coxph( Surv( dur0, dur1, event) ~
strata(eventn) + x)
This works fine under the breslow and efron method. However, since I have a
fair number of ties, especially of repeated events while previous events are
still ongoing, the exact method seems advisable.
The help says that the exact method...
2012 Sep 03
2
Coxph not converging with continuous variable
...: 0.3260 Mean :0.9906 Mean :0.5 Mean :0.4997 Mean : 6.8948
3rd Qu.:0.178325 3rd Qu.: 0.1783 3rd Qu.:1.0000 3rd Qu.:1.0 3rd Qu.:1.0000 3rd Qu.: 7.7409
Max. :5.000000 Max. :52.8990 Max. :1.0000 Max. :1.0 Max. :1.0000 Max. :431.2779
> exp((cox1 <- coxph(Surv(t1, d1)~ x1 + z1+ z2, ties="breslow"))[[1]]) #hrs
x1 z1 z2
3.3782387 0.4925040 0.4850214
Warning message:
In fitter(X, Y, strats, offset, init, control, weights = weights, :
Ran out of iterations and did not converge
#accelerated failure time...