R Subscript-methods “[”的方法：在“Matrix”包中提取或取子集

說明

"[" 的方法，即大部分矩陣的提取或子集，位於包 Matrix 中。

方法

還有更多：

x = "Matrix"，i = "missing"，j = "missing"，下降= "ANY"

...

x = "Matrix"，i = "numeric"，j = "missing"，下降= "missing"

...

x = "Matrix"，i = "missing"，j = "numeric"，下降= "missing"

...

x = "dsparseMatrix"，i = "missing"，j = "numeric"，下降= "logical"

...

x = "dsparseMatrix"，i = "numeric"，j = "missing"，下降= "logical"

...

x = "dsparseMatrix"，i = "numeric"，j = "numeric"，下降= "logical"

...

例子

str(m <- Matrix(round(rnorm(7*4),2), nrow = 7))
stopifnot(identical(m, m[]))
m[2, 3]   # simple number
m[2, 3:4] # simple numeric of length 2
m[2, 3:4, drop=FALSE] # sub matrix of class 'dgeMatrix'
## rows or columns only:
m[1,]     # first row, as simple numeric vector
m[,1:2]   # sub matrix of first two columns

showMethods("[", inherited = FALSE)

也可以看看

[<-methods 用於對 "Matrix" 對象進行子分配。 Extract 關於標準提取。