在Julia中找到一维数组中所有缺失值的索引

时间:2018-09-30 21:24:25

标签: julia missing-data

此堆栈link显示了如何为数组中的booleans值返回missing

例如:

julia> A = [1, 2, 3, missing, 4, 5, 6, missing, 7, 8, missing, 9, 10]
13-element Array{Union{Missing, Int64},1}:
  1
  2
  3
   missing
  4
  5
  6
   missing
  7
  8
   missing
  9
 10

julia> ismissing.(A)
13-element BitArray{1}:
 false
 false
 false
  true
 false
 false
 false
  true
 false
 false
  true
 false
 false

您如何返回他们的索引?

1 个答案:

答案 0 :(得分:1)

使用相同的示例,您可以这样做:

julia> A = [1, 2, 3, missing, 4, 5, 6, missing, 7, 8, missing, 9, 10]
13-element Array{Union{Missing, Int64},1}:
  1
  2
  3
   missing
  4
  5
  6
   missing
  7
  8
   missing
  9
 10

# Below are the indices of the missing elements.
julia> findall(ismissing, A)
3-element Array{Int64,1}:
  4
  8
 11

您还可以查找是否有任何或所有元素为missing,以及第一个和最后一个索引:

julia> any(ismissing, A)
true

julia> all(ismissing, A)
false

julia> findfirst(ismissing, A)
4

julia> findlast(ismissing, A)
11