在“R 中的贝叶斯网络”一书中,作者使用 Grow - Shrink 实现来学习标记数据集的结构。我应该期望 gs 函数为学习结构提供不同的输出吗?也许也许只是从等价类中学习一个结构?
让我感到困惑的是,我运行下面的代码并得到输出:
Bayesian network learned via Constraint-based methods
model:
[undirected graph]
nodes: 5
arcs: 6
undirected arcs: 6
directed arcs: 0
average markov blanket size: 2.40
average neighbourhood size: 2.40
average branching factor: 0.00
learning algorithm: Grow-Shrink
conditional independence test: Pearson's Correlation
alpha threshold: 0.05
tests used in the learning procedure: 80
但在书中,他们声称得到了有向图
Bayesian network learned via Constraint-based methods
model:
[STAT][ANL|STAT] [ALG|ANL:STAT] [VECT|ALG] [MECH|VECT:ALG]
nodes: 5
arcs: 6
undirected arcs: 0
directed arcs: 6
average markov blanket size: 2.40
average neighbourhood size: 2.40
average branching factor: 1.20
learning algorithm: Grow-Shrink
conditional independence test: Pearson's Correlation
alpha threshold: 0.05
tests used in the learning procedure: 32
optimized TRUE
根据书中的内容,他们运行的唯一代码是
bn.gs = gs(marks)
bn.gs
我运行的代码是
library(bnlearn)
bn_gs = gs(marks)
bn_gs
可能有什么不同?