函数内使用sfApply时的范围界定问题(包装降雪 - R) [英] Scoping problem when sfApply is used within function (package snowfall - R)
问题描述
#Runnable代码。不要忘记用sfStop()
require(snowfall)
sfInit(parallel = TRUE,cpus = 3)
func1 < - function(x) {
y< -x + 1
y
}
func2 < - function(x){
y< - sfApply(x,2,函数(i)func1(i))
y
}
y < - matrix(1:10,ncol = 2)
func2(y)
sfStop()
这给出:
> func2(y)
checkForRemoteErrors(val)错误:
2个节点产生错误;第一个错误:找不到函数func1
如果我将函数嵌套到另一个函数中,有用。当我在全局环境中使用sfApply()时,它也可以工作。事情是,我不想在功能2中嵌套函数func1,因为这会导致func1被定义多次(func2用于类似循环的结构中)。
我试过已经简化了代码以摆脱双循环,但由于问题的性质,这是不可能的。任何想法?
我想你想 sfExport(func1)
,但我不确定是否需要在 .GlobalEnv
中或 func2
中执行此操作。希望这有助于......
> y< - 矩阵(1:10,ncol = 2)
> sfExport(list = list(func1))
> func2(y)
[,1] [,2]
[1,] 2 7
[2,] 3 8
[3,] 4 9
[4,] 5 10
[5,] 6 11
Let me add another scoping problem in R, this time with the snowfall package. If I define a function in my global environment, and I try to use that one later in an sfApply() inside another function, my first function isn't found any more :
#Runnable code. Don't forget to stop the cluster with sfStop()
require(snowfall)
sfInit(parallel=TRUE,cpus=3)
func1 <- function(x){
y <- x+1
y
}
func2 <- function(x){
y <- sfApply(x,2,function(i) func1(i) )
y
}
y <- matrix(1:10,ncol=2)
func2(y)
sfStop()
This gives :
> func2(y)
Error in checkForRemoteErrors(val) :
2 nodes produced errors; first error: could not find function "func1"
If I nest my function inside the other function however, it works. It also works when I use the sfApply() in the global environment. Thing is, I don't want to nest my function func1 inside that function2, as that would cause that func1 is defined many times (func2 is used in a loop-like structure).
I've tried already simplifying the code to get rid of the double looping, but that's quite impossible due to the nature of the problem. Any ideas?
I think you want to sfExport(func1)
, though I'm not sure if you need to do it in your .GlobalEnv
or inside of func2
. Hope that helps...
> y <- matrix(1:10,ncol=2)
> sfExport(list=list("func1"))
> func2(y)
[,1] [,2]
[1,] 2 7
[2,] 3 8
[3,] 4 9
[4,] 5 10
[5,] 6 11
这篇关于函数内使用sfApply时的范围界定问题(包装降雪 - R)的文章就介绍到这了,希望我们推荐的答案对大家有所帮助,也希望大家多多支持IT屋!