R语言compareGroups中示例数据predimed有6000+总样本，请问如何只提取部分样本？

R语言compareGroups中示例数据predimed有6000+总样本，请问如何只提取部分样本？

installed.packages("compareGroups")
library(compareGroups)
data(predimed)
data(predimed)
View(predimed)
str(predimed)
descrTable(~.,data=predimed)
descrTable(group ~.,data = predimed,show.all = TRUE)
data <- data[row.names=1:3000,]

data <- data[row.names=1:3000,]
Error in data[row.names = 1:3000, ] :
object of type 'closure' is not subsettable

请问如何只提取部分样本？

可以规定提取哪一行，几行几列