Displaying 20 results from an estimated 300 matches similar to: "problem with abline"
2010 Mar 05
1
How to parse the arguments from a function call and evaluate them in a dataframe?
Hi,
I would like to write a function which has the following syntax:
myfn <- function(formula, ftime, fstatus, data) {
# step 1: obtain terms in `formula' from dataframe `data'
# step 2: obtain ftime from `data'
# step 3: obtain fstatus from `data'
# step 4: do model estimation
# step 5: return results
}
The user would call this function as:
myfn(formula=myform,
2009 Aug 02
1
Competing Risks Regression with qualitative predictor with more than 2 categories
Hello,
I have a question regarding competing risk regression using cmprsk package (function crr()). I am using R2.9.1. How can I do to assess the effect of qualitative predictor (gg) with more than two categories (a,b,c) categorie c is the reference category. See above results, gg is considered like a ordered predictor !
Thank you for your help
Jan
> # simulated data to test
> set.seed(10)
2009 May 15
1
Plotting question re. cuminc
Hello everyone,
(This is my second question posted today on the R list).
I am carrying out a competing risks analysis using the cuminc function...this takes the form:
cuminc(ftime,fstatus,group)
In my study, fstatus has 3 different causes of failure (1,2,3) there are also censored cases (0). "group" has two levels (0 and 1).
I therefore have 6 different cumulative incidence curves:
2013 Oct 18
1
crr question in library(cmprsk)
Hi all
I do not understand why I am getting the following error message. Can
anybody help me with this? Thanks in advance.
install.packages("cmprsk")
library(cmprsk)
result1 <-crr(ftime, fstatus, cov1, failcode=1, cencode=0 )
one.pout1 = predict(result1,cov1,X=cbind(1,one.z1,one.z2))
predict.crr(result1,cov1,X=cbind(1,one.z1,one.z2))
Error: could not find function
2007 Nov 09
3
Normalizing grouped data in a data frame
Hi
I am a newbie to R but have tried a number of ways in R to do this and
can't find a good solution. (I could do it out of R in perl or awk but
would like to know how to do this in R).
I have a large data frame 49 variables and 7000 observations however for
simplicity I can express it in the following data frame
Base, Image, LVEF, ES_Time
A, 1, 4.32, 0.89
A, 2, 4.98, 0.67
A, 3, 3.7, 0.5
2009 Jun 25
2
crr - computationally singular
Dear R-help,
I'm very sorry to ask 2 questions in a week. I am using the package
'crr' and it does exactly what I need it to when I use the dataset a.
However, when I use dataset b I get the following error message:
Error in drop(.Call("La_dgesv", a, as.matrix(b), tol, PACKAGE = "base")) :
system is computationally singular: reciprocal condition number =
2009 Oct 27
1
Error in solve.default peforming Competing risk regression
Dear all,
I am trying to use the crr function in the cmprsk
package version 2.2 to analyse 198 observations.I have receive the
error in solve.default.
Can anyone give me some
insights into where the problem is?
Thanks
here is my script :
cov=cbind(x1,x2)
z<-crr(ftime,fstatus,cov))
and data file:
x1 x2 fstatus ftime
0 .02 1 263
0 .03 1 113
0 .03 1 523
2007 Jul 24
1
Fit t distribution
Hi all, I am trying to fit t distribution using the function "tFit" in the
library(fBasics).
I am using the code tFit(datac[[2]]) and it returns the following list.
Title:
Student-t Parameter Estimation
Call:
tFit(x = datac[[2]])
Model:
Student-t Distribution
Estimated Parameter(s):
df
78.4428
I just wonder how can I refer to the estimated parameters. I tried
2011 Oct 05
1
Require Information
Hi there!
I would like to ask kindly for some further information concerning Rsync
software.
What I am planning to do is to replicate data (database) at certain
intervals.
My first question is, can I do this with Rsync?
To be more specific I have a mysql database at a point and I want this
database to be replicated to a remote side at real-time.
In other words I need to setup a backup
2008 Apr 25
3
Use of survreg.distributions
Dear R-user:
I am using survreg(Surv()) for fitting a Tobit model of left-censored longitudinal data. For logarithmic transformation of y data, I am trying use survreg.distributions in the following way:
tfit=survreg(Surv(y, y>=-5, type="left")~x + cluster(id), dist="gaussian", data=y.data, scale=0, weights=w)
my.gaussian<-survreg.distributions$gaussian
2008 Dec 02
1
Left-truncated regression
Hi.
I am looking for a function for left-truncated data.
I have one data set with 2 variables (Hours~Yrs_Ed).
I already left-censored the data at 200 and left-truncated it at the same
spot, so that I am able to make 2 estimations (one for censoring and one for
truncation).
I know how to make the linear regression for the left-censored variable
(hours) and how to plot the regression line into the
2009 May 15
1
Function Surv and interpretation
Dear everyone,
My question involves the use of the survival object.
We can have
Surv(time,time2,event, type=, origin = 0) (1)
As detailed on p.65 of:
http://cran.r-project.org/web/packages/survival/survival.pdf
My data (used in my study) is 'right censored' i.e. my variable corresponding to 'event' indicates whether a person is alive (0) or dead (1) at date last seen
2006 Jan 19
2
Tobit estimation?
Folks,
Based on
http://www.biostat.wustl.edu/archives/html/s-news/1999-06/msg00125.html
I thought I should experiment with using survreg() to estimate tobit
models.
I start by simulating a data frame with 100 observations from a tobit model
> x1 <- runif(100)
> x2 <- runif(100)*3
> ystar <- 2 + 3*x1 - 4*x2 + rnorm(100)*2
> y <- ystar
> censored <- ystar <= 0
2008 Mar 03
1
Problem plotting curve on survival curve
Calum had a long question about drawing survival curves after fitting a Weibull
model, using pweibull, which I have not reproduced.
It is easier to get survival curves using the predict function. Here is a
simple example:
> library(survival)
> tfit <- survreg(Surv(time, status) ~ factor(ph.ecog), data=lung)
> table(lung$ph.ecog)
0 1 2 3 <NA>
63 113 50 1
2008 Dec 09
1
controlling axes in plot.cuminc (cmprsk library)
Dear R-help list members,
I am trying to create my own axes when plotting a cumulative incidence
curve using the plot.cuminc function in the CMPRSK library. The default
x-axis places tick marks and labels at 0, 20, 40, 60, and 80 (my data has
an upper limit of 96), whereas I want them at my own specified locations.
Here is my example code:
library(cmprsk)
attach(MYDATA)
MYCUMINC <-
2012 Oct 19
1
Looping survdiff
The number of recent questions from umn.edu makes me wonder if there's homework involved....
Simpler for your example is to use get and subset.
dat <- structure(..... as found below
var.to.test <- names(dat)[4:6] #variables of interest
nvar <- length(var.to.test)
chisq <- double(nvar)
for (i in 1:nvar) {
tfit <- survdiff(Surv(time, completion==2) ~
2004 Dec 21
4
Removing trailing spaces
Some years ago when I used S-PLUS, I seem to remember, there was a
discussion about a simple method of removing trailing spaces from
vector elements. I'd be fairly sure the same would work in R, but I
can't find any mention of anything like it in the R archives or with
help.search().
There are ways I could do it with substring(), but I seem to remember
there was something more elegant.
2007 Dec 05
4
coxme frailty model standard errors?
Hello,
I am running R 2.6.1 on windows xp
I am trying to fit a cox proportional hazard model with a shared
Gaussian frailty term using coxme
My model is specified as:
nofit1<-coxme(Surv(Age,cen1new)~ Sex+bo2+bo3,random=~1|isl,data=mydat)
With x1-x3 being dummy variables, and isl being the community level
variable with 4 levels.
Does anyone know if there is a way to get the standard error
2012 Oct 11
2
Question on survival
Hi,
I'm going crazy trying to plot a quite simple graph.
i need to plot estimated hazard rate from a cox model.
supposing the model i like this:
coxPhMod=coxph(Surv(TIME, EV) ~ AGE+A+B+strata(C) data=data)
with 4 level for C.
how can i obtain a graph with 4 estimated (better smoothed) hazard curve
(base-line hazard + 3 proportional) to highlight the effect of C.
thanks!!
laudan
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2008 May 12
3
help with rpart
Hi,
I am using rpart as a part of my masters' project. I am trying to print out
the resulting model using plot() function along with text() function. I am
having difficulties with labels being cut-off. In text() function, I am
using use.n=T option to get the number of people in each nodes but the on
the lower and left part of the plot, the numbers get cut off. Thanks!
Linus
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