问题描述
为什么这不做我认为应该做的事情:
Why doesn't this do what I think it should:
benjamin@benjamin-VirtualBox:~$ julia -p 3
julia> @everywhere(function foom(bar::Vector{Any}, k::Integer) println(repeat(bar[2],bar[1])); return bar; end)
julia> foo={{1,"a"},{2,"b"},{3,"c"}}
julia> pmap(foom, foo, 5)
From worker 2: a
1-element Array{Any,1}:
{1,"a"}
,这就是它的全部输出.我期望pmap遍历foo中的每个元组并在其上调用foom.
and that is all it outputs. I was expecting pmap to iterate through each tuple in foo and call foom on it.
当我在以下地方不传递其他参数时,它将正常工作:
It works correctly when I don't pass other arguments in:
julia> @everywhere(function foom(bar::Vector{Any}) println(repeat(bar[2],bar[1])); return bar; end)
julia> pmap(foom, foo)
From worker 3: bb
From worker 2: a
From worker 4: ccc
3-element Array{Any,1}:
{1,"a"}
{2,"b"}
{3,"c"}
如何将更多参数传递给pmap?
How can I pass in more arguments to pmap?
推荐答案
函数 pmap 确实接受任意数量的参数,每个参数都是一个集合
The function pmap does take any number of arguments each one a collection
function pmap(f, lsts...; err_retry=true, err_stop=false)
函数f将为每个集合发送一个参数
The function f will be sent an argument for each collection
julia> @everywhere f(s,count)=(println("process id = $(myid()) s = $s count = $count");repeat(s,count))
pmap使用1
julia> pmap((a1,a2)->f(a1,a2),{"a","b","c"},{2,1,3})
From worker 3: process id = 3 s = b count = 1
From worker 2: process id = 2 s = a count = 2
From worker 4: process id = 4 s = c count = 3
3-element Array{Any,1}:
"aa"
"b"
"ccc"
pmap使用2
或者,参数可以作为一个外部集合中的参数集合发送,该外部集合可以被填充为目标函数的多个参数
pmap use 2
Alternately, arguments can be sent as collection of arguments from one outer collection which can be spatted into multiple arguments for the target function
julia> pmap((args)->f(args...),{{"a",2},{"b",1},{"c",3}})
From worker 2: process id = 2 s = a count = 2
From worker 3: process id = 3 s = b count = 1
From worker 4: process id = 4 s = c count = 3
3-element Array{Any,1}:
"aa"
"b"
"ccc"
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