Dear R-listers,
Does anybody know what is the correct source of "rats" dataset in
survival package?
The help gives the following information:
Rat data from survival5
Description:
48 rats were injected with a carcinogen, and then randomized to
either drug or placebo. The number of tumors ranges from 0 to 13;
all rats were censored at 6 months after randomization.
Usage:
data(rats)
Format:
rat: id
rx: treatment,(1=drug, 0=control)
observation: within rat
start: entry time
stop: exit time
status: event status
Source:
Gail, Sautner and Brown, Biometrics 36, 255-66, 1980
but "rats" data.frame contains the variables:
names(rats)
[1] "litter" "rx" "time" "status"
It seems to be 150 rats grouped in 50 litters, and 1 mouse is treated at each
one. So this dataset does not agree with the description above mentioned.
I am very interesting in knowing the reference of this data.
PS/ BTW, the correct source of rats injected with a carcinogen is Gail, Santner
and Brown,...
Thanks you very much in advance,
Juan
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Gonzalez Ruiz, Juan Ramon <jrgonzalez <at> ico.scs.es> writes: : : Dear R-listers, : : Does anybody know what is the correct source of "rats" dataset in survival package? : : The help gives the following information: : : Rat data from survival5 : Description: : 48 rats were injected with a carcinogen, and then randomized to : either drug or placebo. The number of tumors ranges from 0 to 13; : all rats were censored at 6 months after randomization. : Usage: : data(rats) : Format: : rat: id : rx: treatment,(1=drug, 0=control) : observation: within rat : start: entry time : stop: exit time : status: event status : Source: : Gail, Sautner and Brown, Biometrics 36, 255-66, 1980 : : but "rats" data.frame contains the variables: : : names(rats) : [1] "litter" "rx" "time" "status" : : It seems to be 150 rats grouped in 50 litters, and 1 mouse is treated at each one. So this dataset does not agree : with the description above mentioned. : : I am very interesting in knowing the reference of this data. : : PS/ BTW, the correct source of rats injected with a carcinogen is Gail, Santner and Brown,... : Not sure what your question is but the rats data set is also in the mimR package and the ?rats help there may be of use. library(mimR) data(rats) ?rats