func itemsetCommonAncestor(patterns []lattice.Pattern) (_ lattice.Pattern, err error) {
var items types.Set
for i, pat := range patterns {
p := pat.(*itemset.Pattern)
if i == 0 {
items = p.Items
} else {
items, err = items.Intersect(p.Items)
if err != nil {
return nil, err
}
}
}
return &itemset.Pattern{items.(*set.SortedSet)}, nil
}
func jaccardSetSimilarity(a, b types.Set) float64 {
i, err := a.Intersect(b)
exc.ThrowOnError(err)
inter := float64(i.Size())
return 1.0 - (inter / (float64(a.Size()) + float64(b.Size()) - inter))
}
func (n *Node) Parents() ([]lattice.Node, error) {
if n.pat.Items.Size() == 0 {
return []lattice.Node{}, nil
} else if n.pat.Items.Size() == 1 {
return []lattice.Node{n.dt.empty}, nil
}
i := setToInt32s(n.pat.Items)
if has, err := n.dt.ParentCount.Has(i); err != nil {
return nil, err
} else if has {
return n.cached(n.dt.Parents, i)
}
parents := make([]*set.SortedSet, 0, n.pat.Items.Size())
for item, next := n.pat.Items.Items()(); next != nil; item, next = next() {
parent := n.pat.Items.Copy()
parent.Delete(item)
parents = append(parents, parent)
}
nodes := make([]lattice.Node, 0, 10)
for _, items := range parents {
if node, err := TryLoadNode(setToInt32s(items), n.dt); err != nil {
return nil, err
} else if node != nil {
nodes = append(nodes, node)
continue
}
ctxs := int32sToSet(n.txs)
var txs types.Set
for item, next := items.Items()(); next != nil; item, next = next() {
mytxs := set.NewSortedSet(len(n.txs) + 10)
for _, tx := range n.dt.InvertedIndex[item.(types.Int32)] {
if !ctxs.Has(types.Int32(tx)) {
mytxs.Add(types.Int32(tx))
}
}
var err error
if txs == nil {
txs = mytxs
} else {
txs, err = txs.Intersect(mytxs)
if err != nil {
return nil, err
}
}
}
txs, err := txs.Union(ctxs)
if err != nil {
return nil, err
}
stxs := make([]int32, 0, txs.Size())
for item, next := txs.Items()(); next != nil; item, next = next() {
stxs = append(stxs, int32(item.(types.Int32)))
}
node := &Node{Pattern{items}, n.dt, stxs}
err = node.Save()
if err != nil {
return nil, err
}
nodes = append(nodes, node)
}
err := n.cache(n.dt.ParentCount, n.dt.Parents, i, nodes)
if err != nil {
return nil, err
}
return nodes, nil
}