Displaying 20 results from an estimated 500 matches similar to: "ask for a question with cch function"
2008 Jul 15
0
implementation of Prentice method in cch()
Case cohort function cch() is in survival package. In cch(), the prentice
method is implemented like this:
Prentice <- function(tenter, texit, cc, id, X, ntot,robust){
eps <- 0.00000001
cens <- as.numeric(cc>0) # Censorship indicators
subcoh <- as.numeric(cc<2) # Subcohort indicators
## Calculate Prentice estimate
ent2 <- tenter
ent2[cc==2] <-
2013 Aug 23
1
A couple of questions regarding the survival:::cch function
Dear all,
I have a couple of questions regarding the survival:::cch function.
1) I notice that Prentice and Self-Prentice functions are giving identical standard errors (not by chance but by programming design) while their estimates are different. My guess is they are both using the standard error form from Self and Prentice (1986). I see that standard errors for both methods are
2008 Jun 16
1
回复: cch() and coxph() for case-cohort
I tried to compare if cch() and coxph() can generate same result for
same case cohort data
Use the standard data in cch(): nwtco
Since in cch contains the cohort size=4028, while ccoh.data size =1154
after selection, but coxph does not contain info of cohort size=4028.
The rough estimate between coxph() and cch() is same, but the lower
and upper CI and P-value are a little different. Can we
2008 Jun 16
0
cch() and coxph() for case-cohort
--------- begin included message ---------
I tried to compare if cch() and coxph() can generate same result for
same case cohort data
Use the standard data in cch(): nwtco
Since in cch contains the cohort size=4028, while ccoh.data size =1154
after selection, but coxph does not contain info of cohort size=4028.
The rough estimate between coxph() and cch() is same, but the lower
and upper CI
2008 Jun 11
0
I wonder if cch function in Survival package can calculate time dependent covariate
Hi
In case cohort study, we can fit proportional hazard regression model to
case-cohort data. In R, the function is cch() in Survival package
Now I am working on case cohort analysis with time dependent covariates
using cch() of "Survival" R package. I wonder if cch() provide this utility
or not?
The cch() manual does not say if time dependent covariate is allowed
I know coxph() in
2008 Jun 12
1
cch function and time dependent covariates
----- begin included message
In case cohort study, we can fit proportional hazard regression model to
case-cohort data. In R, the function is cch() in Survival package
Now I am working on case cohort analysis with time dependent covariates
using cch() of "Survival" R package. I wonder if cch() provide this utility
or not?
The cch() manual does not say if time dependent covariate is
2008 Jun 17
3
Capturing coxph warnings and errors
Hi,
I have a script that takes a subset of genes on a microarray and tries
to fit a coxph model to the expression values for each gene. This seems
to work fine but in some cases it produces warnings and/or errors.
For example:
Error in fitter(X, Y, strats, offset, init, control, weights = weights, :
NA/NaN/Inf in foreign function call (arg 6)
In addition: Warning message:
In fitter(X, Y,
2009 Dec 02
2
Error when running Conditional Logit Model
Dear R-helpers,
I am very new to R and trying to run the conditional logit model using
"clogit " command.
I have more than 4000 observations in my dataset and try to predict the
dependent variable from 14 independent variables. My command is as follows
clmtest1 <-
clogit(Pin~Income+Bus+Pop+Urbpro+Health+Student+Grad+NE+NW+NCC+SCC+CH+SE+MRD+strata(IDD),data=clmdata)
However, it
2011 Mar 31
2
fit.mult.impute() in Hmisc
I tried multiple imputation with aregImpute() and
fit.mult.impute() in Hmisc 3.8-3 (June 2010) and R-2.12.1.
The warning message below suggests that summary(f) of
fit.mult.impute() would only use the last imputed data set.
Thus, the whole imputation process is ignored.
"Not using a Design fitting function; summary(fit)
will use standard errors, t, P from last imputation only.
Use
2007 Feb 05
1
ran out of iteration in coxph
hi,
I applied coxph to my matrix of 300 samples and 215 variables and got the following error
Error in fitter(X, Y, strats, offset, init, control, weights = weights, :
NA/NaN/Inf in foreign function call (arg 6)
In addition: Warning message:
Ran out of iterations and did not converge in: fitter(X, Y, strats, offset, init, control, weights = weights,
26% of time data is censored and here
2004 Jun 15
1
fit.mult.impute and quantile regression
I have a largish dataset (1025) with around .15 of the data missing at random overall, but more like .25 in the dependent variable. I am interested in modelling the data using quantile regression, but do not know how to do this with multiply imputed data (which is what the dataset seems to need). The original plan was to use qr (or whatever) from the quantreg package as the 'fitter'
2004 Feb 10
3
coxph error
R list:
I am using a 'for' loop to run a number of different models (stratified
by different variables) with coxph. The data becomes sparse when some
strata are used causing the model to become unstable. The following
error occurs and the analysis is terminated.
>Error in fitter(X, Y, strats, offset, init, control, weights = weights,
:
(converted from warning) Loglik
2017 Apr 25
3
R-3.4.0 and recommended packages
hello,
I just installed R-3.4.0 from scratch:
$ sudo apt install r-base
but when I try
> library(survival, lib.loc = "/usr/lib/R/library")
> fit <- coxph(Surv(exit, event) ~ x, data = mort)
I get
Error in fitter(X, Y, strats, offset, init, control, weights = weights, :
object 'Ccoxmart' not found
I was told on R-help that I need to
>
2012 Oct 23
1
help using optim function
Hi, am very new to R and I've written an optim function, but can't get it to
work
least.squares.fitter<-function(start.params,gr,low.constraints,high.constraints,model.one.stepper,data,scale,ploton=F)
{
result<-optim(par=start.params,method=c('Nelder-Mead'),fn=least.squares.fit,lower=low.constraints,upper=high.constraints,data=data,scale=scale,ploton=ploton)
2009 Jul 24
1
Fwd: Making rq and bootcov play nice
John,
You can make a local version of bootcov which either:
deletes these arguments from the call to fitter, or
modify the switch statement to include rq.fit,
the latter would need to also modify rq() to return a fitFunction
component, so the first option is simpler. One of these days I'll
incorporate clustered se's into summary.rq, but meanwhile
this seems to be a good alternative.
2010 May 05
1
Error messages with psm and not cph in Hmisc
While
sm4.6ll<-fit.mult.impute(Surv(agesi, si)~partner+ in.love+ pubty+ FPA+
strat(gender),fitter = cph, xtrans = dated.sexrisk2.i, data =
dated.sexrisk2, x=T,y=T,surv=T, time.inc=16)
runs perfectly using Hmisc, Design and mice under R11 run via Sciviews-K,
with
library(Design)
library(mice)
ds2d<-datadist(dated.sexrisk2)
options(datadist="ds2d")
2009 Jul 24
1
Making rq and bootcov play nice
I have a quick question, and I apologize in advance if, in asking, I
expose my woeful ignorance of R and its packages. I am trying to use
the bootcov function to estimate the standard errors for some
regression quantiles using a cluster bootstrap. However, it seems that
bootcov passes arguments that rq.fit doesn't like, preventing the
command from executing. Here is an example:
2009 Dec 30
1
boot function returns the same results every time - there appears to be not resampling of the original data.
R 2.8.1
windows XP
I am trying to learn how to use the boot function to perform a bootstrap of a regression. I have written a short trial program, shown below. Clearly I have done something wrong as the output of each of the 100 bootstrap values for the regression are exactly the same - there does not appear to be any bootstrap respampling!. What have I done wrong?
# Define function to be run.
2007 Dec 17
2
Capture warning messages from coxph()
Hi,
I want to fit multiple cox models using the coxph() function. To do
this, I use a for-loop and save the relevant results in a separate
matrix. In the example below, only two models are fitted (my actual
matrix has many more columns), one gives a warning message, while the
other does not. Right now, I see all the warning message(s) after the
for-loop is completed but have no idea which model
2003 Jul 27
1
multiple imputation with fit.mult.impute in Hmisc
I have always avoided missing data by keeping my distance from
the real world. But I have a student who is doing a study of
real patients. We're trying to test regression models using
multiple imputation. We did the following (roughly):
f <- aregImpute(~ [list of 32 variables, separated by + signs],
n.impute=20, defaultLinear=T, data=t1)
# I read that 20 is better than the default of