parApply、parApply、parSapply是parallel包里面的

apply、lapply、sapply是base包里面自带的。

parApply、parApply、parSapply分别是apply、lapply、sapply的并行运算版本。对应的方法输出结果和使用方式相同，是不过par-需要设定核数（或者使用默认核数计算）

margin

目录

1.apply     对象为数组

Apply Functions Over Array Margins

Description

Usage

Arguments

 2.lapply    对象为向量

Apply a Function over a List or Vector

3.sapply,vapplysapply(X, FUN, ..., simplify = TRUE, USE.NAMES = TRUE)

vapply(X, FUN, FUN.VALUE, ..., USE.NAMES = TRUE)

replicate(n, expr, simplify = "array")

simplify2array(x, higher = TRUE)

 4.parLapply

Apply Operations using Clusters

Description

Usage

parApply

parLapplyparLapply returns a list the length of X.

Arguments

Returns a vector or array or list of values obtained by applying a function to margins of an array or matrix.

 apply(对象，行/列，功能函数)

an array, including a matrix.    要处理的数组对象

a vector giving the subscripts which the function will be applied over. E.g., for a matrix 1 indicates rows, 2 indicates columns, c(1, 2) indicates rows and columns. Where X has named dimnames, it can be a character vector selecting dimension names.    1表示行，2表示列，c（1，2)表示行列

the function to be applied: see ‘Details’. In the case of functions like +, %*%, etc., the function name must be backquoted or quoted.    可以是自己定义的功能函数

optional arguments to FUN.   省略号中的内容为fun函数自己的参数。所以会不一样

 example：