Question: How to convert class name into single quote?

[mattn]

I'm trying to train/predict iris.csv and got problem that can not pass string attributes into Fit since CategoryAttribute is not FloatAttribute. I want to know how to convert "Iris-setosa", "Iris-versicolor" and "Iris-virsinica" into 0, 1, 2 or (0.0, 0.3333, 0.6666). Could you please let me know the way?

package main

import (
	"fmt"
	"log"

	"github.com/sjwhitworth/golearn/base"
	"github.com/sjwhitworth/golearn/evaluation"
	"github.com/sjwhitworth/golearn/linear_models"
)

func main() {
	inst, err := base.ParseCSVToInstances("datasets/iris.csv", false)
	if err != nil {
		log.Fatal(err)
	}

	lr, err := linear_models.NewLogisticRegression("l2", 1.0, 1e-6)
	if err != nil {
		log.Fatal(err)
	}

	trainData, testData := base.InstancesTrainTestSplit(inst, 0.50)

	lr.Fit(trainData)

	pred, err := lr.Predict(testData)
	if err != nil {
		log.Fatal(err)
	}
	confusionMat, err := evaluation.GetConfusionMatrix(testData, pred)
	if err != nil {
		log.Fatal(err)
	}
	fmt.Println(evaluation.GetSummary(confusionMat))
}