编辑代码

attach(mtcars)
res = lm(mpg~disp)
a=data.frame(disp= c(22,11,33))
predict(res, newdata=a)
my_matrix1 <-matrix(1:20, nrow=5, ncol=4)
my_vector<-c(1:4)
rnames<-c("R1", 'R2')
cnames<-c('C1', 'C2')
my_matrix2 <-matrix(my_vector, nrow=2, ncol=2, byrow=T,dimnames=list(rnames, cnames))
my_matrix1[2, 3]
my_matrix1[1, ]
my_matrix1[1:2, 2]
patientID<-c(1, 2, 3, 4)
age <-c(25, 34, 28, 52)
diabetes <-c("Type1", "Type2", "Type1", "Type1")
status <-c("poor", "improved", "poor", "improved")
patient_data<-data.frame(patientID, age, diabetes, status)
with(patient_data, {summary(age);summary(patientID);})
diabetes <-c("Type1", "Type2", "Type1", "Type1")
status <-c("poor", "improved", "poor", "improved")
diabetes <-factor(diabetes)
diabetes
mylist = list(my_matrix1, patientID, a, diabetes)
length(my_matrix1)
dim(my_matrix1)
str(mylist)
class(mpg)
class(mylist)
head(mtcars)
tail(mtcars)