Displaying 20 results from an estimated 400 matches similar to: "time dependent hazard ratios"
2004 Nov 09
1
survSplit: further exploration and related topics
To Danardonos concern of splitting time for records with delayed entry:
This can fairly easily be accomodated, by simply splitting time in small
intervals of time since entry into the study, and then compute the value
of the other timescales for each of these e.g.:
current.age <- time.from.entry + age.at.entry
but the cut on the other timescales will not be exactly where you may
want
them
2009 Jul 13
1
survSplit with data.frame containing a Surv object
Dear All,
since years I am struggling with Surv objects in data.frames. The
following seems to have to do with it.
See below the modified example from the help page of survSplit. The
original works, as expected. If, however, a Surv object is added to
the data.frame, each record gets doubled.
Is there some solution other than avoiding Surv objects in data.frames?
Thanks,
Heinz
2012 Aug 22
1
Error in if (n > 0)
I've searched the Web with Google and do not find what might cause this
particular error from an invocation of cenboxplot:
cenboxplot(cu.t$quant, cu.t$ceneq1, cu.t$era, range=1.5, main='Total
Recoverable Copper', ylab='Concentration (mg/L)', xlab='Time Period')
Error in if (n > 0) (1L:n - a)/(n + 1 - 2 * a) else numeric() :
argument is of length zero
I do
2008 Nov 12
1
read.table with many blanks (reposting)
Thanks Jim for pointing out how to properly ask.
Here is is my question and a small subset of the data and output.
I have a data set with many blanks. The blanks should be replaced with zero
once imported.
I tried read.table, read.csv (R 2.8 version),or scan, but none was
successful.
Any suggestion, please..
thanks.
Keun-Hyung
>garoben=read.table("c:\\Rdata\\garoben.txt",header=T,
2017 Mar 26
1
Documentation of model.frame() and get_all_vars()
Hi everyone,
This is about documentation for the model.frame() page. The
get_all_vars() function (added in R 2.5.0) is a great addition, but
the behavior of its '...' argument is different from that of
model.frame() with which it is documented and this creates ambiguity.
The current docs read:
\item{\dots}{further arguments such as \code{data}, \code{na.action},
\code{subset}. Any
2008 Jul 29
1
Howto Draw Bimodal Gamma Curve with User Supplied Parameters
Hi,
Suppose I have the following vector (data points):
> x
[1] 36.0 57.3 73.3 92.0 300.4 80.9 19.8 31.4 85.8 44.9 24.6 48.0
[13] 28.0 38.3 85.2 103.6 154.4 128.5 38.3 72.4 122.7 123.1 41.8 21.7
[25] 143.6 120.2 46.6 29.2 44.8 25.0 57.3 96.4 29.4 62.9 66.4 30.0
[37] 24.1 14.8 56.6 102.4 117.5 90.4 37.2 79.6 27.8 17.1 26.6 16.3
[49] 41.4 48.9 24.1
2007 Dec 21
1
post hoc in repeated measures of anova
Hallo, I have this dataset with repeated measures. There are two
within-subject factors, "formant" (2 levels: 1 and 2) and "f2 Ref" (25
levels: 670, 729, 788, 846, 905, 1080, 1100, 1120, 1140, 1170, 1480,
1470, 1450, 1440, 1430, 1890, 1840, 1790, 1740, 1690, 2290, 2210,
2120, 2040, 1950), and one between-subject factor, lang (2 levels:1
and 2). The response variable
2007 May 12
2
Implicit vs explicit printing and the call stack
Hi everyone,
I've run into a bit of strange problem with implicit vs explicit
printing and the call stack. I've included an example at the bottom of
this email. The basic problem is that I have an S3 object with a
print method. When the object is implicitly printed (ie. typed
directly into the console) the function arguments in the call stack
are exploded out to their actual values,
2006 May 17
1
question about survSplit
Dear R-users,
I use the survsplit function in the survival package to change my data into
counting-process format
and the transformed format is as follow:
(a)
start stop event DP age ....
0 5 0 1 20
5 10 0 1 20
10 25 1 1 20
looking at the above three entries that belong to the same person, if an
event happen at
2011 Aug 11
2
Extract values from a data frame
Hi everyone,
I have a data frame that looks *sort of* like this:
name <- letters[1:5]
signal.1 <- c("12", "bad signal", "noise", "10", "X")
length.signal.1 <- 5:9
intensity.signal.1 <- 3:7
signal.2 <- c("13", "noise", "19.2", "X", "V")
length.signal.2 <- 2:6
intensity.signal.2
2011 Oct 12
2
Nonlinear regression aborting due to error
Colleagues,
I am fitting an Emax model using nls. The code is:
START <- list(EMAX=INITEMAX, EFFECT=INITEFFECT, C50=INITC50)
CONTROL <- list(maxiter=1000, warnOnly=T)
#FORMULA <- as.formula(YVAR ~ EMAX - EFFECT * XVAR^GAMMA / (XVAR^GAMMA + C50^GAMMA)) ## alternate version of formula
FORMULA <- as.formula(YVAR ~ EMAX - EFFECT / (1 + (C50/XVAR)^GAMMA))
FIT <-
2004 Nov 17
1
Re: variations on the theme of survSplit
Danardono <daodao99 at student.umu.se> wrote:
>
> While waiting for 2.1, for those who need function[s] for this
> survival-splitting business, as I do, this 'survcut' function below
> might be helpful.
> It is not an elegant nor efficient function but it works, at least for
> some examples below.
>
Ditto the following, for the case where there are multiple
2008 Jan 24
3
Reshaping a dataframe with conditional summary of columns - apply or reshape?
I need to do a somewhat complex rearrangement of an existing dataframe that
involves an "on-the-fly" conditional summary as well. I've tried to make
the example as simple as possible. Code to produce the object being acted
on is at the end of the message. I hope this isn't too much for a single
posting. Any guidance will be much appreciated.
The input example looks like
2004 Nov 06
1
Typo in Samba HOWTO collection example 19.2
-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1
Hi,
Since the samba-docs mailing list is closed, I figured this was the best
place to post this.
I believe there's a typo in example 19.2 ("Overriding global CUPS
settings for one printer") of the official Samba HOWTO collection. The
"print command" parameter in the [special_printer] section contains
several echo commands,
2006 Jul 02
2
how to recode in my dataset?
Dear Rusers,
My question is about "recode variables". First, i'd like to say
something about the idea of recoding:
My dataset have three variables:type,soiltem and airtem,which means
grass type, soil temperature and air temperature. As we all known, the
change of air temperature is greater than soil temperature,so the
values in those two different temperaturemay represent different
2019 Nov 19
2
Why is matrix product slower when matrix has very small values?
Hi,
I experience surprisingly large timing differences for the
multiplication of matrices of the same dimension. An example is given
below. How can this be explained?
I posted the question on Stackoverflow:
https://stackoverflow.com/questions/58886111/r-why-is-matrix-product-slower-when-matrix-has-very-small-values
Somebody could reproduce the behavior but I did not get any useful
explanations
2008 Nov 20
2
Removing rows with rowsums==0 (I can't figure this out)
##I want to remove the rows where the row sums are zero and this is as
far as I have gotten
ffg <- (structure(list(CD = c(0, 0, 0, 0, 3.125, 0, 0, 0, 0, 1.6, 3.125,
0, 0, 6.25, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 3.125, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1.6, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 1.6, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 3.125, 0, 0, 0, 0, 0, 0, 0, 0,
2011 Feb 10
2
Getting p-value from summary output
I can get this summary of a model that I am running:
summary(myprobit)
Call:
glm(formula = Response_Slot ~ trial_no, family = binomial(link = "probit"),
data = neg_data, na.action = na.pass)
Deviance Residuals:
Min 1Q Median 3Q Max
-0.9528 -0.8934 -0.8418 1.4420 1.6026
Coefficients:
Estimate Std. Error z value Pr(>|z|)
2009 May 14
2
How to do a pretty panel plot?
The pretty picture that I saw at:
http://chartsgraphs.wordpress.com/2009/02/09/r-panel-chart-beats-excel-chart/#more-1096
inspired me to try something similar. The code that I wrote is:
------snipsnip---------------------------------------------------------------------
M <- structure(list(date = structure(c(13634, 13665, 13695, 13726,
13757, 13787, 13818, 13848, 13879, 13910, 13939, 13970,
2006 Apr 07
1
Aggregating an its series
I'm using a very long irregular time-series of air temperature and
relative humidity of this kind (this is an extract only)
its.format("%
Y%d%m %X)
> base
T H
20020601
12.00.00 27.1 47
20020601 15.00.00 29.1 39
20020601 18.00.00 27.4 39
20020601 21.00.00 24.0 40
20020602 0.00.00 22.0 73
20020602 3.00.00
19.2 49
20020602 6.00.00 19.5 74
20020602