Displaying 20 results from an estimated 400 matches similar to: "Trend test for survival data"
2007 Jun 05
4
Refactor all factors in a data frame
Hi all,
Assume I have a data frame with numerical and factor variables that I
got through merging various other data frames and subsetting the
resulting data frame afterwards. The number levels of the factors seem
to be the same as in the original data frames, probably because subset()
calls [.factor without drop = TRUE (that's what I gather from scanning
the mailing lists).
I wonder if
2003 Mar 11
1
objectname completion
Dear R users,
is there any possibility to get an object-name completion within the R
command line (UNIX-version of R). As I got to know from the FAQ that
this is possible from within Emacs (ESS), but without using Emacs?
Thank's
Ingo
--
-----------------------------------------------------------------
Ingo Roeder
Institute for Medical Informatics, Statistics and Epidemiology
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,
2011 Oct 29
1
How to plot survival data from multiple trials (simulations)?
Dear all:
Could anyone please provide some R codes to plot the below survival data to compare two groups (0 vs 1) after 2 simulations (TRL)? need 95% prediction interval on the plot from these 2 trials. I would like to simulate 1000 trials later. Thanks a lot for your great help and consideration!
yan
TRL ID ECOG BASE PTR8 GROUP POP ST ind
1 1 1 1 2.2636717 0.255634126 1 1 99.4 F
3 1 2 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
2009 Aug 01
2
Cox ridge regression
Hello,
I have questions regarding penalized Cox regression using survival
package (functions coxph() and ridge()). I am using R 2.8.0 on Ubuntu
Linux and survival package version 2.35-4.
Question 1. Consider the following example from help(ridge):
> fit1 <- coxph(Surv(futime, fustat) ~ rx + ridge(age, ecog.ps, theta=1), ovarian)
As I understand, this builds a model in which `rx' is
2000 Jun 20
1
unequalspaced time-series data
Dear R-users,
is there any object-type or routine/function in R which can handle
unequally spaced time-series data? I know that there is the library
OSWALD for S-Plus, which is able to do so, but I was not successful in
running it under R. Does anyone can help?
Thank's in advance!
INGO
--
-----------------------------------------------------------------
Ingo Roeder
Institute for
2001 Sep 13
2
image plot legends
Hi,
is there anybody knowing a possibility to produce a legend
(describing the color scheme) in an image plot in R. In S-Plus
this works using image.legend.
Thank's in advance.
INGO
--
-----------------------------------------------------------------
Ingo Roeder
Institute for Medical Informatics, Statistics and
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$ph.ecog)
0 1 2 3 <NA>
63 113 50 1
2009 Feb 06
1
Using subset in validate() in Design, what is the correct syntax?
Hi
I am trying to understand how to get the validate() function in Design
to work with the subset option. I tried this:
ovarian.cph=cph(Surv(futime, fustat) ~ age+factor(ecog.ps)+strat(rx),
time.inc=1000, x=T, y=T, data=ovarian)
validate(ovarian.cph)
#fine when no subset is used, but the following two don't work:
> validate(ovarian.cph, subset=ovarian$ecog.ps==2)
Error in
2011 Jan 24
1
How to measure/rank ?variable importance when using rpart?
--- included message ----
Thus, my question is: *What common measures exists for ranking/measuring
variable importance of participating variables in a CART model? And how
can
this be computed using R (for example, when using the rpart package)*
---end ----
Consider the following printout from rpart
summary(rpart(time ~ age + ph.ecog + pat.karno, data=lung))
Node number 1: 228 observations,
2005 Nov 27
1
the output of coxph
Dear All:
I have some questions about the output of coxph.
Below is the input and output:
----------------------------------------
> coxph(formula = Surv(futime, fustat) ~ age + rx + ecog.ps, data =
+ ovarian, x = TRUE)
Call:
coxph(formula = Surv(futime, fustat) ~ age + rx + ecog.ps, data =
ovarian, x = TRUE)
coef exp(coef) se(coef) z p
age 0.147 1.158
2003 Feb 27
2
interval-censored data in survreg()
I am trying to fit a lognormal distribution on interval-censored
data. Some of my intervals have a lower bound of zero.
Unfortunately, it seems like survreg() cannot deal with lower
bounds of zero, despite the fact that plnorm(0)==0 and
pnorm(-Inf)==0 are well defined. Below is a short example to
reproduce the problem.
Does anyone know why survreg() must behave that way?
Is there an alternate
2006 Jan 17
1
Font size of axis labels
Hi all,
In R, it is not possible to set the font size of axis labels directly
(AFAIK). Instead, scaling factors for the font chosen by the graphics
device can be supplied. It appears that there is no constant font size
for axis labels. My impression is that the axis label font size is
scaled internally by R depending on the number of labels given for an axis.
In addition to the R-internal
2011 Aug 16
3
window, samba and ldap passwords
Hi,
I recently migrated to a Samba3x domain. One issue that has been
reported to me is that XP users cannot change their password from
their PC. I have done some searching and I haven't seen a straight
forward answer to this.
My config is
ldap primary + Samba PDC on host A
ldap slave + samba BDC on host B
I see this error in the machine log when someone attempts to change
their password:
2010 Mar 05
2
Defining a method in two packages
The coxme package has a ranef() method, as does lme4. I'm having
trouble getting them to play together, as shown below. (The particular
model in the example isn't defensible, but uses a standard data set.)
The problem is that most of the time only one of lme4 or coxme will be
loaded, so each needs to define the basic ranef function as well as a
method for it. But when loaded together
2018 Jan 15
1
Time-dependent coefficients in a Cox model with categorical variants
Suppose I have a dataset contain three variants, looks like
> head(dta)
Sex tumorsize Histology time status
0 1.5 2 12.1000 0
1 1.8 1 38.4000 0
.....................
Sex: 1 for male; 0 for female., two levels
Histology: 1 for SqCC; 2 for High risk AC; 3 for low risk AC,
2008 Jul 02
1
survival package test stats
Hello,
Is there a function in the survival package that will allow me to test a subset of independent variables for joint significance? I am thinking along the lines of a Wald, likelihood ratio, or F-test. I am using the survreg procedure to estimate my parameters. Thank you.
Geoff
Geoffrey Smith
Visiting Assistant Professor
Department of Finance
University of Illinois at Urbana-Champaign
2011 May 14
2
Survreg object
Hi,Just a quick one, does anyone know the command for accessing the standard errors from a survreg object? I can access the coefficients by model$coefficients, but I cant seem to find a command to access the errors. Any help would be greatly appreciated.Regards,Andre
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