R-变量

变量不需要声明，

常用的变量有：

变量类型	定义	例子	例子效果
logical	逻辑型：TRUE , FALSE	v<-TRUE; print(class(v))	"logical"
numeric	数字型：23.4, 2 ,	v<-23.5;print(class(v))	"numeric"
integer	整型：2L, 0L	v<-2L;print(class(v))	"numeric"
complex	复合型	v<-3+2i;print(class(v))	"complex"
character	字符型：'a',"FALSE"	v<-"TRUE";print(class(v))	"character"
raw	原型："Hello" 被存储为 48 65 6c 6c 6f	v<-charToRaw("Hello"); print(class(v)); print(v)	[1] "raw" [1] 48 65 6c 6c 6f
vectors		apple<-c("red","green"); print(apple); print(class(apple))	[1] "red" "green" [1] "character"
list	列表型	list1<-list(c(2,5,3),21.3,sin)；print(list1); print(class(list1))	[[1]] [1] 2 5 3 [[2]] [1] 21.3 [[3]] function (x) .Primitive("sin") ################ [1] "list"
Matrices	矩阵型	M=matrix(c('a','a','b'),nrow=2,ncol=3,byrow=TRUE); print(M)	[,1] [,2] [,3] [1,] "a" "a" "b" [2,] "a" "a" "b"
array	数组型	#包含两个元素的数组，每个元素为2x3个矩阵 a <- array(c('green','yellow','e'),dim = c(2,3,2)); print(a)	, , 1 [,1] [,2] [,3] [1,] "green" "green" "green" [2,] "yellow" "yellow" "yellow" , , 2 [,1] [,2] [,3] [1,] "green" "green" "green" [2,] "yellow" "yellow"  "yellow"
factor	因子： 它将向量与向量中元素的不同值一起存储为标签。 标签总是字符， 不管它在输入向量中是数字还是字符或布尔等。	apple_colors<-c('green','green','yellow','red'); factor_apple<-factor(apple_colors); print(factor_apple); print(class(factor_apple)); print(nlevels(factor_apple))	[1] green green yellow red Levels: green red yellow [1] "factor" [1] 3
data.frame	数据帧：表格数据对象	BMI <- data.frame( gender = c("Male", "Male","Female"), height = c(152, 171.5, 165), weight = c(81,93, 78), Age = c(42,38,26) ) print(BMI)	gender height weight Age 1 Male 152.0 81 42 2 Male 171.5 93 38 3 Female 165.0 78 26