// Run applies a trained BinningFilter to a set of Instances,
// discretising any numeric attributes added.
//
// IMPORTANT: Run discretises in-place, so make sure to take
// a copy if the original instances are still needed
//
// IMPORTANT: This function panic()s if the filter has not been
// trained. Call Build() before running this function
//
// IMPORTANT: Call Build() after adding any additional attributes.
// Otherwise, the training structure will be out of date from
// the values expected and could cause a panic.
func (b *BinningFilter) Run(on *base.Instances) {
if !b.trained {
panic("Call Build() beforehand")
}
for attr := range b.Attributes {
minVal := b.MinVals[attr]
maxVal := b.MaxVals[attr]
disc := 0
// Casts to float32 to replicate a floating point precision error
delta := float32(maxVal - minVal)
delta /= float32(b.BinCount)
for i := 0; i < on.Rows; i++ {
val := on.Get(i, attr)
if val <= minVal {
disc = 0
} else {
disc = int(math.Floor(float64(float32(val-minVal) / delta)))
if disc >= b.BinCount {
disc = b.BinCount - 1
}
}
on.Set(i, attr, float64(disc))
}
newAttribute := new(base.CategoricalAttribute)
newAttribute.SetName(on.GetAttr(attr).GetName())
for i := 0; i < b.BinCount; i++ {
newAttribute.GetSysValFromString(fmt.Sprintf("%d", i))
}
on.ReplaceAttr(attr, newAttribute)
}
}
// Run discretises the set of Instances `on'
//
// IMPORTANT: ChiMergeFilter discretises in place.
func (c *ChiMergeFilter) Run(on *base.Instances) {
if !c._Trained {
panic("Call Build() beforehand")
}
for attr := range c.Tables {
table := c.Tables[attr]
for i := 0; i < on.Rows; i++ {
val := on.Get(i, attr)
dis := 0
for j, k := range table {
if k.Value < val {
dis = j
continue
}
break
}
on.Set(i, attr, float64(dis))
}
newAttribute := new(base.CategoricalAttribute)
newAttribute.SetName(on.GetAttr(attr).GetName())
for _, k := range table {
newAttribute.GetSysValFromString(fmt.Sprintf("%f", k.Value))
}
on.ReplaceAttr(attr, newAttribute)
}
}
// GetAttributesAfterFiltering gets a list of before/after
// Attributes as base.FilteredAttributes
func (c *ChiMergeFilter) GetAttributesAfterFiltering() []base.FilteredAttribute {
oldAttrs := c.train.AllAttributes()
ret := make([]base.FilteredAttribute, len(oldAttrs))
for i, a := range oldAttrs {
if c.attrs[a] {
retAttr := new(base.CategoricalAttribute)
retAttr.SetName(a.GetName())
for _, k := range c.tables[a] {
retAttr.GetSysValFromString(fmt.Sprintf("%f", k.Value))
}
ret[i] = base.FilteredAttribute{a, retAttr}
} else {
ret[i] = base.FilteredAttribute{a, a}
}
}
return ret
}
// Fit creates n filtered datasets (where n is the number of values
// a CategoricalAttribute can take) and uses them to train the
// underlying classifiers.
func (m *OneVsAllModel) Fit(using base.FixedDataGrid) {
var classAttr *base.CategoricalAttribute
// Do some validation
classAttrs := using.AllClassAttributes()
for _, a := range classAttrs {
if c, ok := a.(*base.CategoricalAttribute); !ok {
panic("Unsupported ClassAttribute type")
} else {
classAttr = c
}
}
attrs := m.generateAttributes(using)
// Find the highest stored value
val := uint64(0)
classVals := classAttr.GetValues()
for _, s := range classVals {
cur := base.UnpackBytesToU64(classAttr.GetSysValFromString(s))
if cur > val {
val = cur
}
}
if val == 0 {
panic("Must have more than one class!")
}
m.maxClassVal = val
// Create individual filtered instances for training
filters := make([]*oneVsAllFilter, val+1)
classifiers := make([]base.Classifier, val+1)
for i := uint64(0); i <= val; i++ {
f := &oneVsAllFilter{
attrs,
classAttr,
i,
}
filters[i] = f
classifiers[i] = m.NewClassifierFunction(classVals[int(i)])
classifiers[i].Fit(base.NewLazilyFilteredInstances(using, f))
}
m.filters = filters
m.classifiers = classifiers
}
// GetAttributesAfterFiltering gets a list of before/after
// Attributes as base.FilteredAttributes
func (b *BinningFilter) GetAttributesAfterFiltering() []base.FilteredAttribute {
oldAttrs := b.train.AllAttributes()
ret := make([]base.FilteredAttribute, len(oldAttrs))
for i, a := range oldAttrs {
if b.attrs[a] {
retAttr := new(base.CategoricalAttribute)
minVal := b.minVals[a]
maxVal := b.maxVals[a]
delta := float64(maxVal-minVal) / float64(b.bins)
retAttr.SetName(a.GetName())
for i := 0; i <= b.bins; i++ {
floatVal := float64(i)*delta + minVal
fmtStr := fmt.Sprintf("%%.%df", a.(*base.FloatAttribute).Precision)
binVal := fmt.Sprintf(fmtStr, floatVal)
retAttr.GetSysValFromString(binVal)
}
ret[i] = base.FilteredAttribute{a, retAttr}
} else {
ret[i] = base.FilteredAttribute{a, a}
}
}
return ret
}