Displaying 20 results from an estimated 4000 matches similar to: "controling the size of vectors in a matrix"
2007 May 07
4
creating a new column
hie l would like to create a 6th column "actual surv time" from the following data
the condition being
if censoringTime>survivaltime then actual survtime =survival time
else actual survtime =censoring time
the code l used to create the data is
s=2
while(s!=0){ n=20
m<-matrix(nrow=n,ncol=4)
2007 May 17
1
creating columns
l would like to create the following matrice
treatmentgrp strata
1 1 1 1 1 1 1 2 1 2 1 2 2 1 2 1 2 1 2 2 2 2 2 2 l should be able to choose the size of the treatment grps and stratas the method l used intially creates the
2007 May 07
2
computing logrank statistic/test
hie how do you compute the logrank test using R
what commands do you use my data looks something like just an example
treatmentgrp strata censoringTime survivalTime censoring act.surv.time
[1,] 2 2 42.89005 1847.3358 1 42.89005
[2,] 1 1 74.40379 440.3467 1 74.40379
[3,] 2 2
2007 Apr 26
3
adding a column to a matrix
i would like to add a variable to an existing matrix by manipulating 2 previous variables eg for the data
m
treat strata censti survTime
[1,] 1 2 284.684074 690.4961005
[2,] 1 1 172.764515 32.3990335
[3,] 1 1 2393.195400 24.6145279
[4,] 2 1 30.364771 8.0272267
[5,] 1 1 523.182282 554.7659501
l
2007 May 10
0
getting the normal dist from the chisqr with 1df
l used the following code to generate a sample and then calculated then did a log rank test.can l get the normal version of the logrank eg sqrt of the chisqr(1) will give you the N~(0,1).
from my sample can i use the above expression to get the normal dist from the result of the log rank test.
thank
s=1
while(s!=0){ n=100
m<-matrix(nrow=n,ncol=4)
2007 May 01
1
adding column to a matrix
l have the following dataset and would like to calculate the actual survival time by
if censoring time > survival time then actual survival time =survival time else its= censoring time.
treatmentgrp strata censoringTime survivalTime censoring actualsurvivaltim
[1,] 1 1 1.012159 1137.80922 0
[2,] 2 2
2007 Oct 29
3
using survfit
hie
when i use plot.survfit to plot more than one graph why I only see the last graph how do i see the other graphs.for example
n=20
n1=n/2
n2=n/4
a11=4;a12=4 ;a21=4 ;a22=4
t1<-array(1,c(n1))
t2<-array(2,c(n1))
treatgrp=matrix(c(t1,t2))
2007 May 16
2
creating different strata
hie
l would like to create about ten strata l have tried using
sample(c(1,2),1,replace=TRUE) but all l get is a vector of 1 and 2 if i change it to sample(c(1,10),1,replace=TRUE) it gives me a vector of 1 and 10 how do l go about it
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2007 Oct 18
1
programming question
hie
i'm tryimg to generate two survival data using the following code (I know its ugly ) but it seems to repeat two of the variables can any one tell me whats the porblem.
n=20
n1=n/2
n2=n/4
a11=1 ;a12=1.4 ;a21=16 ;a22=a12 * a21
t1<-array(1,c(n1))
t2<-array(2,c(n1))
treatgrp=matrix(c(t1,t2))
2007 Apr 25
2
creating random numbers
l want to create a column of 1 and 2 randomly what command should l use
eg
treatment strata
1 1
2 0
1 1
2 1
2 0
2 1
2 0
1 0
these should be created randomly
secondly if l have
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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2007 Nov 13
3
cronbach's alpha
hie
1...i'm trying to carryout a relibility testusing cronbach's alpha what fuctin do i use.
2.. this is more of a statistical question.if the alpha value for all the variables is negative what does it mean. and if the alpha value is negative for all tyha variables but is greater than 0.7 for some sections of the variables what does that mean
thanks in advance
2007 Nov 12
2
specifying decimal places
hie
how do I specify the number of decuimal places for my calulations
thanks
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2011 Jan 25
1
NA replacing
Hello R user,
I have following data frame:
df=data.frame(id=c(1:10),strata=rep(c(1,2),c(5,5)),y=c(
10,12,10,NA,15,70,NA,NA,55,100),x=c(3,4,5,7,4,10,12,8,3,15))
and I would like to replace NA's with:
instead of first NA tapply(na.exclude(df)$y,na.exclude(df)$strata,sum)[1]*
*7 */tapply(na.exclude(df)$x,na.exclude(df)$strata,sum)[1]
where 7 is the value of x (id=4) in strata 1 where y=NA
2015 Feb 04
2
Interpretación de coeficientes en un cox proportional hazards con variable strata
Buenas.
Abajo pongo la salida de un modelo de cox , dónde he estratificado por
una variable de país (Countryb) y por otra (Q6). Además hay interacción
entre la variable mobilityPDurG2 (es una variable 0,1, y 0 es la
categoría de referencia) país.
La categoría de referencia para país es "united kingdom".
Mi duda surge si quiero calcular el hazard ratio para los que tienen un
1
2013 Jan 31
1
obtainl survival curves for single strata
Dear useRs,
What is the syntax to obtain survival curves for single strata on many subjects?
I have a model based on Surv(time,response) object, so there is a single row per subject and no start,stop and no switching of strata.
The newdata has many subjects and each subject has a strata and the survival based on the subject risk and the subject strata is needed.
If I do
newpred <-
2008 Dec 04
1
Comparing survival curves with "survdiff" "strata" help
ExpeRts,
I'm trying to compare three survival curves using the function "survdiff" in the survival package. Following is my code and corresponding error message.
> survdiff(Surv(st_months, status) ~ strata(BOR), data=mydata)
Error in survdiff(Surv(st_months, status) ~ strata(BOR), data = mydata) :
No groups to test
When I check the "strata" of the variable. I get .
2003 Feb 12
2
Various Errors using Survey Package
Hi,
I have been experimenting with the new Survey package. Specifically, I was
trying to use some of the functions on the public-use survey data from NHIS
(2000 Sample Adult file).
Error 1): The first error I get is when I try to specify the complex survey
design.
nhis.design<-svydesign(ids=~psu, probs=~probs, strata=~strata, data=nhis.df,
check.strata=TRUE)
Error in svydesign(ids =
2011 Feb 12
4
From SPSS Syntax to R code
There is a code from SPSS Syntax
do if sub(ATVK,2,2)="01".
comp strata=1.
else if sub(ATVK,2,2)>="05" and sub(ATVK,2,2)<="27".
comp strata=3.
else if sub(ATVK,4,2)>"20" or sub(ATVK,6,2)>"20".
comp strata=4.
else if sub(ATVK,4,2)>"00".
comp strata=2.
end if.
value labels strata 1 "R 2 "Li" 3 "M" 4
2007 May 01
7
logrank test
how do l programme the logrank test. l am trying to compare 2 survival curves
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