Golang ClasetInterface.GetClassType Examples

Example #1

File: cart.go Project: shuLhan/go-mining

/*
computeGain calculate the gini index for each value in each attribute.
*/
func (runtime *Runtime) computeGain(D tabula.ClasetInterface) (
	gains []gini.Gini,
) {
	switch runtime.SplitMethod {
	case SplitMethodGini:
		// create gains value for all attribute minus target class.
		gains = make([]gini.Gini, D.GetNColumn())
	}

	runtime.SelectRandomFeature(D)

	classVS := D.GetClassValueSpace()
	classIdx := D.GetClassIndex()
	classType := D.GetClassType()

	for x, col := range *D.GetColumns() {
		// skip class attribute.
		if x == classIdx {
			continue
		}

		// skip column flagged with parent
		if (col.Flag & ColFlagParent) == ColFlagParent {
			gains[x].Skip = true
			continue
		}

		// ignore column flagged with skip
		if (col.Flag & ColFlagSkip) == ColFlagSkip {
			gains[x].Skip = true
			continue
		}

		// compute gain.
		if col.GetType() == tabula.TReal {
			attr := col.ToFloatSlice()

			if classType == tabula.TString {
				target := D.GetClassAsStrings()
				gains[x].ComputeContinu(&attr, &target,
					&classVS)
			} else {
				targetReal := D.GetClassAsReals()
				classVSReal := tekstus.StringsToFloat64(
					classVS)

				gains[x].ComputeContinuFloat(&attr,
					&targetReal, &classVSReal)
			}
		} else {
			attr := col.ToStringSlice()
			attrV := col.ValueSpace

			if DEBUG >= 2 {
				fmt.Println("[cart] attr :", attr)
				fmt.Println("[cart] attrV:", attrV)
			}

			target := D.GetClassAsStrings()
			gains[x].ComputeDiscrete(&attr, &attrV, &target,
				&classVS)
		}

		if DEBUG >= 2 {
			fmt.Println("[cart] gain :", gains[x])
		}
	}
	return
}