mirror of
https://github.com/sjwhitworth/golearn.git
synced 2025-04-25 13:48:49 +08:00
base: Cleaned up duplicate Attribute resolution functions
This commit is contained in:
parent
ff97065261
commit
47341b2869
@ -129,7 +129,7 @@ func ParseCSVBuildInstances(filepath string, hasHeaders bool, u UpdatableDataGri
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rowCounter := 0
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specs := ResolveAllAttributes(u, u.AllAttributes())
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specs := ResolveAttributes(u, u.AllAttributes())
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for {
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record, err := reader.Read()
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@ -379,7 +379,7 @@ func (inst *DenseInstances) Size() (int, int) {
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// swapRows swaps over rows i and j
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func (inst *DenseInstances) swapRows(i, j int) {
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as := GetAllAttributeSpecs(inst)
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as := ResolveAllAttributes(inst)
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for _, a := range as {
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v1 := inst.Get(a, i)
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v2 := inst.Get(a, j)
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@ -424,7 +424,7 @@ func (inst *DenseInstances) String() string {
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var buffer bytes.Buffer
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// Get all Attribute information
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as := GetAllAttributeSpecs(inst)
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as := ResolveAllAttributes(inst)
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// Print header
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cols, rows := inst.Size()
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@ -153,7 +153,7 @@ func (l *LazilyFilteredInstances) MapOverRows(asv []AttributeSpec, mapFunc func(
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func (l *LazilyFilteredInstances) RowString(row int) string {
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var buffer bytes.Buffer
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as := GetAllAttributeSpecs(l) // Retrieve all Attribute data
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as := ResolveAllAttributes(l) // Retrieve all Attribute data
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first := true // Decide whether to prefix
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for _, a := range as {
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@ -188,7 +188,7 @@ func (l *LazilyFilteredInstances) String() string {
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}
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// Get all Attribute information
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as := GetAllAttributeSpecs(l)
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as := ResolveAllAttributes(l)
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// Print header
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buffer.WriteString("Lazily filtered instances using ")
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@ -17,8 +17,8 @@ func TestLazySortDesc(testEnv *testing.T) {
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return
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}
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as1 := GetAllAttributeSpecs(inst1)
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as2 := GetAllAttributeSpecs(inst2)
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as1 := ResolveAllAttributes(inst1)
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as2 := ResolveAllAttributes(inst2)
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if isSortedDesc(inst1, as1[0]) {
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testEnv.Error("Can't test descending sort order")
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@ -44,7 +44,7 @@ func TestLazySortDesc(testEnv *testing.T) {
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func TestLazySortAsc(testEnv *testing.T) {
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inst, err := ParseCSVToInstances("../examples/datasets/iris_headers.csv", true)
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as1 := GetAllAttributeSpecs(inst)
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as1 := ResolveAllAttributes(inst)
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if isSortedAsc(inst, as1[0]) {
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testEnv.Error("Can't test ascending sort on something ascending already")
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}
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@ -67,7 +67,7 @@ func TestLazySortAsc(testEnv *testing.T) {
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testEnv.Error(err)
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return
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}
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as2 := GetAllAttributeSpecs(inst2)
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as2 := ResolveAllAttributes(inst2)
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if !isSortedAsc(inst2, as2[0]) {
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testEnv.Error("This file should be sorted in ascending order")
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}
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@ -44,8 +44,8 @@ func TestSortDesc(testEnv *testing.T) {
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return
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}
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as1 := GetAllAttributeSpecs(inst1)
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as2 := GetAllAttributeSpecs(inst2)
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as1 := ResolveAllAttributes(inst1)
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as2 := ResolveAllAttributes(inst2)
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if isSortedDesc(inst1, as1[0]) {
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testEnv.Error("Can't test descending sort order")
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@ -71,7 +71,7 @@ func TestSortDesc(testEnv *testing.T) {
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func TestSortAsc(testEnv *testing.T) {
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inst, err := ParseCSVToInstances("../examples/datasets/iris_headers.csv", true)
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as1 := GetAllAttributeSpecs(inst)
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as1 := ResolveAllAttributes(inst)
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if isSortedAsc(inst, as1[0]) {
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testEnv.Error("Can't test ascending sort on something ascending already")
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}
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@ -90,7 +90,7 @@ func TestSortAsc(testEnv *testing.T) {
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testEnv.Error(err)
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return
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}
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as2 := GetAllAttributeSpecs(inst2)
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as2 := ResolveAllAttributes(inst2)
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if !isSortedAsc(inst2, as2[0]) {
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testEnv.Error("This file should be sorted in ascending order")
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}
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@ -38,9 +38,9 @@ func NonClassAttributes(d DataGrid) []Attribute {
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return AttributeDifferenceReferences(allAttrs, classAttrs)
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}
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// ResolveAllAttributes returns AttributeSpecs describing
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// ResolveAttributes returns AttributeSpecs describing
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// all of the Attributes.
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func ResolveAllAttributes(d DataGrid, attrs []Attribute) []AttributeSpec {
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func ResolveAttributes(d DataGrid, attrs []Attribute) []AttributeSpec {
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ret := make([]AttributeSpec, len(attrs))
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for i, a := range attrs {
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spec, err := d.GetAttribute(a)
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@ -52,25 +52,9 @@ func ResolveAllAttributes(d DataGrid, attrs []Attribute) []AttributeSpec {
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return ret
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}
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// GetAllAttributeSpecs retrieves every Attribute specification
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// from a given DataGrid. Useful in conjunction with MapOverRows.
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func GetAllAttributeSpecs(from DataGrid) []AttributeSpec {
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attrs := from.AllAttributes()
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return GetSomeAttributeSpecs(from, attrs)
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}
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// GetSomeAttributeSpecs returns a subset of Attribute specifications
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// from a given DataGrid.
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func GetSomeAttributeSpecs(from DataGrid, attrs []Attribute) []AttributeSpec {
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ret := make([]AttributeSpec, len(attrs))
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for i, a := range attrs {
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as, err := from.GetAttribute(a)
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if err != nil {
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panic(err)
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}
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ret[i] = as
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}
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return ret
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// ResolveAllAttributes returns every AttributeSpec
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func ResolveAllAttributes(d DataGrid) []AttributeSpec {
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return ResolveAttributes(d, d.AllAttributes())
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}
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func buildAttrSet(a []Attribute) map[Attribute]bool {
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@ -144,7 +144,7 @@ func DecomposeOnAttributeValues(inst FixedDataGrid, at Attribute) map[string]Fix
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rowMaps := make(map[string][]int)
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// Build full Attribute set
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fullAttrSpec := ResolveAllAttributes(inst, newAttrs)
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fullAttrSpec := ResolveAttributes(inst, newAttrs)
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fullAttrSpec = append(fullAttrSpec, attrSpec)
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// Decompose
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@ -78,7 +78,7 @@ func NewInstancesViewFromRows(src FixedDataGrid, rows map[int]int) *InstancesVie
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func NewInstancesViewFromVisible(src FixedDataGrid, rows []int, attrs []Attribute) *InstancesView {
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ret := &InstancesView{
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src,
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GetSomeAttributeSpecs(src, attrs),
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ResolveAttributes(src, attrs),
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make(map[int]int),
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make(map[Attribute]bool),
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true,
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@ -99,7 +99,7 @@ func NewInstancesViewFromVisible(src FixedDataGrid, rows []int, attrs []Attribut
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func NewInstancesViewFromAttrs(src FixedDataGrid, attrs []Attribute) *InstancesView {
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ret := &InstancesView{
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src,
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GetSomeAttributeSpecs(src, attrs),
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ResolveAttributes(src, attrs),
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nil,
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make(map[Attribute]bool),
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false,
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@ -252,7 +252,7 @@ func (v *InstancesView) String() string {
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maxRows := 30
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// Get all Attribute information
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as := GetAllAttributeSpecs(v)
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as := ResolveAllAttributes(v)
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// Print header
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cols, rows := v.Size()
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@ -305,7 +305,7 @@ func (v *InstancesView) String() string {
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// RowString returns a string representation of a given row.
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func (v *InstancesView) RowString(row int) string {
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var buffer bytes.Buffer
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as := GetAllAttributeSpecs(v)
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as := ResolveAllAttributes(v)
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first := true
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for _, a := range as {
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val := v.Get(a, row)
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@ -46,7 +46,7 @@ func main() {
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// for doing so is not very sophisticated.
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// First, have to resolve Attribute Specifications
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as := base.ResolveAllAttributes(rawData, rawData.AllAttributes())
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as := base.ResolveAttributes(rawData, rawData.AllAttributes())
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// Attribute Specifications describe where a given column lives
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rawData.Set(as[0], 0, as[0].GetAttribute().GetSysValFromString("1.00"))
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@ -112,7 +112,7 @@ func TestChiMerge2(testEnv *testing.T) {
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// Sort the instances
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allAttrs := inst.AllAttributes()
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sortAttrSpecs := base.ResolveAllAttributes(inst, allAttrs)[0:1]
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sortAttrSpecs := base.ResolveAttributes(inst, allAttrs)[0:1]
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instSorted, err := base.Sort(inst, base.Ascending, sortAttrSpecs)
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if err != nil {
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panic(err)
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@ -65,8 +65,8 @@ func (KNN *KNNClassifier) Predict(what base.FixedDataGrid) base.FixedDataGrid {
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ret := base.GeneratePredictionVector(what)
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// Resolve Attribute specifications for both
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whatAttrSpecs := base.ResolveAllAttributes(what, allNumericAttrs)
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trainAttrSpecs := base.ResolveAllAttributes(KNN.TrainingData, allNumericAttrs)
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whatAttrSpecs := base.ResolveAttributes(what, allNumericAttrs)
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trainAttrSpecs := base.ResolveAttributes(KNN.TrainingData, allNumericAttrs)
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// Reserve storage for most the most similar items
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distances := make(map[int]float64)
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@ -34,7 +34,7 @@ func convertInstancesToProblemVec(X base.FixedDataGrid) [][]float64 {
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// Retrieve numeric non-class Attributes
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numericAttrs := base.NonClassFloatAttributes(X)
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numericAttrSpecs := base.ResolveAllAttributes(X, numericAttrs)
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numericAttrSpecs := base.ResolveAttributes(X, numericAttrs)
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// Convert each row
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X.MapOverRows(numericAttrSpecs, func(row [][]byte, rowNo int) (bool, error) {
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@ -66,7 +66,7 @@ func convertInstancesToLabelVec(X base.FixedDataGrid) []float64 {
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_, rows := X.Size()
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labelVec := make([]float64, rows)
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// Resolve class Attribute specification
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classAttrSpecs := base.ResolveAllAttributes(X, classAttrs)
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classAttrSpecs := base.ResolveAttributes(X, classAttrs)
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X.MapOverRows(classAttrSpecs, func(row [][]byte, rowNo int) (bool, error) {
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labelVec[rowNo] = base.UnpackBytesToFloat(row[0])
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return true, nil
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@ -90,10 +90,10 @@ func (lr *LogisticRegression) Predict(X base.FixedDataGrid) base.FixedDataGrid {
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}
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// Generate return structure
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ret := base.GeneratePredictionVector(X)
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classAttrSpecs := base.ResolveAllAttributes(ret, classAttrs)
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classAttrSpecs := base.ResolveAttributes(ret, classAttrs)
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// Retrieve numeric non-class Attributes
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numericAttrs := base.NonClassFloatAttributes(X)
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numericAttrSpecs := base.ResolveAllAttributes(X, numericAttrs)
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numericAttrSpecs := base.ResolveAttributes(X, numericAttrs)
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// Allocate row storage
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row := make([]float64, len(numericAttrSpecs))
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@ -112,7 +112,7 @@ func (b *BaggedModel) Predict(from base.FixedDataGrid) base.FixedDataGrid {
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for { // Need to resolve the voting problem
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incoming, ok := <-votes
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if ok {
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cSpecs := base.ResolveAllAttributes(incoming, incoming.AllClassAttributes())
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cSpecs := base.ResolveAttributes(incoming, incoming.AllClassAttributes())
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incoming.MapOverRows(cSpecs, func(row [][]byte, predRow int) (bool, error) {
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// Check if we've seen this class before...
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if _, ok := voting[predRow]; !ok {
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@ -1,8 +1,8 @@
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package naive
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import (
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"math"
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base "github.com/sjwhitworth/golearn/base"
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base "github.com/sjwhitworth/golearn/base"
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"math"
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)
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// A Bernoulli Naive Bayes Classifier. Naive Bayes classifiers assumes
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@ -37,91 +37,103 @@ import (
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// Information Retrieval. Cambridge University Press, pp. 234-265.
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// http://nlp.stanford.edu/IR-book/html/htmledition/the-bernoulli-model-1.html
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type BernoulliNBClassifier struct {
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base.BaseEstimator
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// Conditional probability for each term. This vector should be
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// accessed in the following way: p(f|c) = condProb[c][f].
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// Logarithm is used in order to avoid underflow.
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condProb map[string][]float64
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// Number of instances in each class. This is necessary in order to
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// calculate the laplace smooth value during the Predict step.
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classInstances map[string]int
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// Number of instances used in training.
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trainingInstances int
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// Number of features in the training set
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features int
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base.BaseEstimator
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// Conditional probability for each term. This vector should be
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// accessed in the following way: p(f|c) = condProb[c][f].
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// Logarithm is used in order to avoid underflow.
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condProb map[string][]float64
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// Number of instances in each class. This is necessary in order to
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// calculate the laplace smooth value during the Predict step.
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classInstances map[string]int
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// Number of instances used in training.
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trainingInstances int
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// Number of features in the training set
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features int
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}
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// Create a new Bernoulli Naive Bayes Classifier. The argument 'classes'
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// is the number of possible labels in the classification task.
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func NewBernoulliNBClassifier() *BernoulliNBClassifier {
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nb := BernoulliNBClassifier{}
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nb.condProb = make(map[string][]float64)
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nb.features = 0
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nb.trainingInstances = 0
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return &nb
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nb := BernoulliNBClassifier{}
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nb.condProb = make(map[string][]float64)
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nb.features = 0
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nb.trainingInstances = 0
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return &nb
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}
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// Fill data matrix with Bernoulli Naive Bayes model. All values
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// necessary for calculating prior probability and p(f_i)
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func (nb *BernoulliNBClassifier) Fit(X *base.Instances) {
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func (nb *BernoulliNBClassifier) Fit(X base.FixedDataGrid) {
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// Number of features and instances in this training set
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nb.trainingInstances = X.Rows
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nb.features = 0
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if X.Rows > 0 {
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nb.features = len(X.GetRowVectorWithoutClass(0))
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}
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// Check that all Attributes are binary
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classAttrs := X.AllClassAttributes()
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allAttrs := X.AllAttributes()
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featAttrs := base.AttributeDifferenceReference(allAttrs, classAttrs)
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for i := range featAttrs {
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if _, ok := featAttrs[i].(*base.BinaryAttribute); !ok {
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panic(fmt.Sprintf("%v: Should be BinaryAttribute", featAttrs[i]))
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}
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}
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featAttrSpecs := base.ResolveAllAttributes(featAttrs, X)
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// Number of instances in class
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nb.classInstances = make(map[string]int)
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// Check that only one classAttribute is defined
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if len(classAttrs) > 0 {
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panic("Only one class Attribute can be used")
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}
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// Number of documents with given term (by class)
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docsContainingTerm := make(map[string][]int)
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// Number of features and instances in this training set
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nb.features, nb.trainingInstances() = X.Size()
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// This algorithm could be vectorized after binarizing the data
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// matrix. Since mat64 doesn't have this function, a iterative
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// version is used.
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for r := 0; r < X.Rows; r++ {
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class := X.GetClass(r)
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docVector := X.GetRowVectorWithoutClass(r)
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// Number of instances in class
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nb.classInstances = make(map[string]int)
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// increment number of instances in class
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t, ok := nb.classInstances[class]
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if !ok { t = 0 }
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nb.classInstances[class] = t + 1
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// Number of documents with given term (by class)
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docsContainingTerm := make(map[string][]int)
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// This algorithm could be vectorized after binarizing the data
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// matrix. Since mat64 doesn't have this function, a iterative
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// version is used.
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X.MapOverRows(featAttrSpecs, func(docVector [][]byte, r int) (bool, error) {
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class := base.GetClass(X, r)
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for feat := 0; feat < len(docVector); feat++ {
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v := docVector[feat]
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// In Bernoulli Naive Bayes the presence and absence of
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// features are considered. All non-zero values are
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// treated as presence.
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if v > 0 {
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// Update number of times this feature appeared within
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// given label.
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t, ok := docsContainingTerm[class]
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if !ok {
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t = make([]int, nb.features)
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docsContainingTerm[class] = t
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}
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t[feat] += 1
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}
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}
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}
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// increment number of instances in class
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t, ok := nb.classInstances[class]
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if !ok {
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t = 0
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}
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nb.classInstances[class] = t + 1
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// Pre-calculate conditional probabilities for each class
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for c, _ := range nb.classInstances {
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nb.condProb[c] = make([]float64, nb.features)
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for feat := 0; feat < nb.features; feat++ {
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classTerms, _ := docsContainingTerm[c]
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numDocs := classTerms[feat]
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docsInClass, _ := nb.classInstances[c]
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for feat := 0; feat < len(docVector); feat++ {
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v := docVector[feat]
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// In Bernoulli Naive Bayes the presence and absence of
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// features are considered. All non-zero values are
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// treated as presence.
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if v[0] > 0 {
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// Update number of times this feature appeared within
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// given label.
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t, ok := docsContainingTerm[class]
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if !ok {
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t = make([]int, nb.features)
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docsContainingTerm[class] = t
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}
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t[feat] += 1
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}
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}
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})
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classCondProb, _ := nb.condProb[c]
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// Calculate conditional probability with laplace smoothing
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classCondProb[feat] = float64(numDocs + 1) / float64(docsInClass + 1)
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}
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}
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// Pre-calculate conditional probabilities for each class
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for c, _ := range nb.classInstances {
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nb.condProb[c] = make([]float64, nb.features)
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for feat := 0; feat < nb.features; feat++ {
|
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classTerms, _ := docsContainingTerm[c]
|
||||
numDocs := classTerms[feat]
|
||||
docsInClass, _ := nb.classInstances[c]
|
||||
|
||||
classCondProb, _ := nb.condProb[c]
|
||||
// Calculate conditional probability with laplace smoothing
|
||||
classCondProb[feat] = float64(numDocs+1) / float64(docsInClass+1)
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
// Use trained model to predict test vector's class. The following
|
||||
@ -134,43 +146,43 @@ func (nb *BernoulliNBClassifier) Fit(X *base.Instances) {
|
||||
// IMPORTANT: PredictOne panics if Fit was not called or if the
|
||||
// document vector and train matrix have a different number of columns.
|
||||
func (nb *BernoulliNBClassifier) PredictOne(vector []float64) string {
|
||||
if nb.features == 0 {
|
||||
panic("Fit should be called before predicting")
|
||||
}
|
||||
if nb.features == 0 {
|
||||
panic("Fit should be called before predicting")
|
||||
}
|
||||
|
||||
if len(vector) != nb.features {
|
||||
panic("Different dimensions in Train and Test sets")
|
||||
}
|
||||
if len(vector) != nb.features {
|
||||
panic("Different dimensions in Train and Test sets")
|
||||
}
|
||||
|
||||
// Currently only the predicted class is returned.
|
||||
bestScore := -math.MaxFloat64
|
||||
bestClass := ""
|
||||
// Currently only the predicted class is returned.
|
||||
bestScore := -math.MaxFloat64
|
||||
bestClass := ""
|
||||
|
||||
for class, classCount := range nb.classInstances {
|
||||
// Init classScore with log(prior)
|
||||
classScore := math.Log((float64(classCount))/float64(nb.trainingInstances))
|
||||
for f := 0; f < nb.features; f++ {
|
||||
if vector[f] > 0 {
|
||||
// Test document has feature c
|
||||
classScore += math.Log(nb.condProb[class][f])
|
||||
} else {
|
||||
if nb.condProb[class][f] == 1.0 {
|
||||
// special case when prob = 1.0, consider laplace
|
||||
// smooth
|
||||
classScore += math.Log(1.0 / float64(nb.classInstances[class] + 1))
|
||||
} else {
|
||||
classScore += math.Log(1.0 - nb.condProb[class][f])
|
||||
}
|
||||
}
|
||||
}
|
||||
for class, classCount := range nb.classInstances {
|
||||
// Init classScore with log(prior)
|
||||
classScore := math.Log((float64(classCount)) / float64(nb.trainingInstances))
|
||||
for f := 0; f < nb.features; f++ {
|
||||
if vector[f] > 0 {
|
||||
// Test document has feature c
|
||||
classScore += math.Log(nb.condProb[class][f])
|
||||
} else {
|
||||
if nb.condProb[class][f] == 1.0 {
|
||||
// special case when prob = 1.0, consider laplace
|
||||
// smooth
|
||||
classScore += math.Log(1.0 / float64(nb.classInstances[class]+1))
|
||||
} else {
|
||||
classScore += math.Log(1.0 - nb.condProb[class][f])
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
if classScore > bestScore {
|
||||
bestScore = classScore
|
||||
bestClass = class
|
||||
}
|
||||
}
|
||||
if classScore > bestScore {
|
||||
bestScore = classScore
|
||||
bestClass = class
|
||||
}
|
||||
}
|
||||
|
||||
return bestClass
|
||||
return bestClass
|
||||
}
|
||||
|
||||
// Predict is just a wrapper for the PredictOne function.
|
||||
@ -178,9 +190,9 @@ func (nb *BernoulliNBClassifier) PredictOne(vector []float64) string {
|
||||
// IMPORTANT: Predict panics if Fit was not called or if the
|
||||
// document vector and train matrix have a different number of columns.
|
||||
func (nb *BernoulliNBClassifier) Predict(what *base.Instances) *base.Instances {
|
||||
ret := what.GeneratePredictionVector()
|
||||
for i := 0; i < what.Rows; i++ {
|
||||
ret.SetAttrStr(i, 0, nb.PredictOne(what.GetRowVectorWithoutClass(i)))
|
||||
}
|
||||
return ret
|
||||
ret := what.GeneratePredictionVector()
|
||||
for i := 0; i < what.Rows; i++ {
|
||||
ret.SetAttrStr(i, 0, nb.PredictOne(what.GetRowVectorWithoutClass(i)))
|
||||
}
|
||||
return ret
|
||||
}
|
||||
|
@ -203,7 +203,7 @@ func (d *DecisionTreeNode) Predict(what base.FixedDataGrid) base.FixedDataGrid {
|
||||
panic(err)
|
||||
}
|
||||
predAttrs := base.AttributeDifferenceReferences(what.AllAttributes(), predictions.AllClassAttributes())
|
||||
predAttrSpecs := base.ResolveAllAttributes(what, predAttrs)
|
||||
predAttrSpecs := base.ResolveAttributes(what, predAttrs)
|
||||
what.MapOverRows(predAttrSpecs, func(row [][]byte, rowNo int) (bool, error) {
|
||||
cur := d
|
||||
for {
|
||||
|
Loading…
x
Reference in New Issue
Block a user