朱莉娅“方法错误：没有与 build_tree 匹配的方法”

Question

我有一个非常简单的示例脚本：

using Pkg
Pkg.add("DecisionTree")
Pkg.add("DataFrames")

using DataFrames
using DecisionTree

dat = DataFrame(A=[1, 2, 3, 4, 5], B=[2, 5, 1, 2, 6])
model = build_tree(dat[!, "A"], dat[!, "B"])

它返回一个错误：

ERROR: LoadError: MethodError: no method matching build_tree(::Vector{Int64}, ::Vector{Int64})
Closest candidates are:
  build_tree(::AbstractVector{T}, ::AbstractMatrix{S}) where {S, T} at C:\Users\**\.julia\packages\DecisionTree\iWCbW\src\classification\main.jl:74
  build_tree(::AbstractVector{T}, ::AbstractMatrix{S}, ::Any) where {S, T} at C:\Users\**\.julia\packages\DecisionTree\iWCbW\src\classification\main.jl:74
  build_tree(::AbstractVector{T}, ::AbstractMatrix{S}, ::Any, ::Any) where {S, T} at C:\Users\**\.julia\packages\DecisionTree\iWCbW\src\classification\main.jl:74

发生了什么？我该如何处理？

Answer 1

您的数据类型不匹配。试试这个：

C = reshape(dat[!, "B"], (1, 5))
model = DecisionTree.build_tree(dat[!, "A"], C')