thanks, it works well. I have to work on Arun's previous answer to make it work
too.
David
>
> De : Rui Barradas
>À : Biau David
>Cc : r help list
>Envoyé le : Mercredi 23 janvier 2013 19h57
>Objet : Re: [R] extracting characters
Dear All,
I have a data frame of vectors of publication names such as 'pub':
pub1 <- c('Brown DK, Santos R, Rome DF, Don Juan X')
pub2 <- c('Benigni D')
pub3 <- c('Arstra SD, Van den Hoops DD, lamarque D')
pub <- rbind(pub1, pub2, pub3)
I would like to construct a dataframe with only author's
ing of the sort?
thanks,
David Biau
>
> De : arun
>À : Biau David
>Cc : R help
>Envoyé le : Mardi 15 janvier 2013 21h54
>Objet : Re: [R] removing loops from code in making data.frame
>
>Hi,
>
>You could also do this:
&
Dear all,
I am working on an author network and to do so I have to arrange a data.frame
(tutu) crossing author names (rows) per publication number (column). The
participation of the author to a study is indicated by a 1 and 0 otherwise.
I have a vector (xaulist) of all the names of authors and
thanks too. It works also perfect. Not sure I understand all the code though:
will have to look into it!
David Biau
>
> De : arun
>À : Biau David
>Cc : R help ; Uwe Ligges
>
>Envoyé le : Dimanche 13 janvier 2013 18h36
>Objet
works great thanks. And you cut off my code a lot and removed the loop.
David Biau
>
> De : Uwe Ligges
>À : Biau David
>Cc : arun ; r help list
>Envoyé le : Dimanche 13 janvier 2013 18h22
>Objet : Re: [R] extracting character values
>
z ds', NA, 'chung p', ' biau dj', 'marmor
s', 'bhumbra r', 'pansuriya tc', NA)
netw <- data.frame(au1, au2, au3)
res <- data.frame(matrix(NA, nrow=dim(netw)[1], ncol=dim(netw)[2]))
for (i in 1:dim(netw)[2])
{
wh <- regexpr('[a-z]{3,}
OK thanks for the tips. I have abandonned the use of cbidn in dataframe. I've
used the obth dcast() and melt() and they both work fine. Thanks again
David Biau
>
> De : David Winsemius
>À : arun
>Cc : R help ; Biau David
>Envoyé le :
Dear all,
I have a dataframe of names (netw), with each cell including last name and
initials of an author; some cells have NA. I would like to extract only the
last name from each cell; this new dataframe is calle 'res'
Here is what I do:
res <- data.frame(matrix(NA, nrow=dim(netw)[1], ncol=
Dear all,
i would like to count the number of times where I have combined occurrences of
the categories of 2 variables.
For instance, in the dataframe below, i would like to know how many times each
author (au1, au2, au3 represent the first, second, third author) is associated
with each of t
Dear Prof Therneau,
thank yo for this information: this is going to be most useful for what I want
to do. I will look into the ACF model.
Yours,
David Biau.
De : Terry Therneau
Cc : r-help@r-project.org
Envoyé le : Lun 15 novembre 2010, 15h 33min 23s
Obje
Dear Prof Lumley,
This is a very clear, precise, and useful answer to all my questions.
Thank you very much.
David Biau.
De : Thomas Lumley
Cc : r help list
Envoyé le : Dim 14 novembre 2010, 23h 54min 23s
Objet : Re: [R] interpretation of coefficients in
_
De : David Winsemius
Cc : r help list
Envoyé le : Sam 13 novembre 2010, 19h 55min 10s
Objet : Re: [R] interpretation of coefficients in survreg AND obtaining the
hazard function for an individual given a set of predictors
On Nov 13, 2010, at 12:51 PM, Biau David wrote:
> Dea
Dear R help list,
I am modeling some survival data with coxph and survreg (dist='weibull') using
package survival. I have 2 problems:
1) I do not understand how to interpret the regression coefficients in the
survreg output and it is not clear, for me, from ?survreg.objects how to.
Here is an
work for your goals, is to embed all models
> in a grand model that is used for inference.
>
> When coefficients ARE comparable in some sense, you can use the bootstrap to
>get
> confidence bands for differences in regressor effects between models.
>
> Frank
>
> Frank E Ha
Frank
Frank E Harrell Jr Professor and ChairmanSchool of Medicine
Department of Biostatistics Vanderbilt University
On Fri, 13 Aug 2010, Biau David wrote:
> Hello,
>
> I would like, if it is possible, to compare the effect of a variable across
> regressi
Hello,
I would like, if it is possible, to compare the effect of a variable across
regression models. I have looked around but I haven't found anything. Maybe
someone could help? Here is the problem:
I am studying the effect of a variable (age) on an outcome (local recurrence:
lr). I have buil
s is coded in print.cph.fit (library(rms))
On 08/05/2010 04:03 PM, Biau David wrote:
> Hello,
>
> I am modeling some survival data wih cph (Design). I have modeled a predictor
> which showed non linear effect with restricted cubic splines. I would like to
> retrieve the se(coef) for
4:03 PM, Biau David wrote:
> Hello,
>
> I am modeling some survival data wih cph (Design). I have modeled a predictor
> which showed non linear effect with restricted cubic splines. I would like to
> retrieve the se(coef) for other, linear, predictors.
The cph object has a
Hello,
I am modeling some survival data wih cph (Design). I have modeled a predictor
which showed non linear effect with restricted cubic splines. I would like to
retrieve the se(coef) for other, linear, predictors. This is just to make nice
LateX tables automatically. I have the coefficients w
rneau, Terry M., Ph.D."
À : David Winsemius ; Biau David
Cc : r help list
Envoyé le : Ven 30 juillet 2010, 19h 07min 15s
Objet : RE: Re : [R] COXPH: how to get the score test and likelihood ratio test
for a specific variable in a multivariate Coxph ?
The Wald, score, and LR tests are discussed
p=2.375e-05
David Biau.
De : David Winsemius
Cc : r help list
Envoyé le : Ven 30 juillet 2010, 17h 34min 28s
Objet : Re: [R] COXPH: how to get the score test and likelihood ratio test for
a
specific variable in a multivariate Coxph ?
On Jul 30, 2010, at 11:08 AM, Biau David wrote:
&g
Hello,
I would like to get the likelihood ratio and score tests for specific variables
in a multivariate coxph model. The default is Wald, so the tests for each
separate variable is based on Wald's test. I have the other tests for the full
model but I don't know how to get them for each variabl
Hi,
I am trying to model a score over time. This score shows a ceiling effect. I
was
willing to use a longitudinal tobit model, such as the one described by Twisk
et
al. (Twisk_Longitudinal tobit regression: A new approach to analyze outcome
variables with floor or ceiling effects_JCE_2009) b
Hi,
>
>I am trying to describe a data.frame by obtaining multiple crosstable summary
>statistics at once. I have tried table, xtab, crosstable, summaryBy and
>describe but none of these functions seems to allow muliple conparisons at
>once.
> Here, is what I would like to do:
>
>I have, for in
Hello,
I have a dataframe (var_1, var_2, ..., var_n) and I would like to export
summary statistics to Latex in the form of a table. I want specific summary
statistics by crossing numerous variables 2x2 AT ONCE. In each cell I would
like sometimes to have the median (Q1 - Q3), or frequency and p
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