gnb_3.kt

// Helper class to load data from given CSV file and transform it into a Array<FeatureColumn>
class DataFrame( context: Context , assetsFileName : String ) {

    // HashMap which stores the CSV data in the form ( Column_Name , Float[] ). Where Float[] holds
    // the feature value for all samples.
    private var featureColumnData = HashMap<String,ArrayList<Float>>()

    // Variable to store the parsed CSV file from `CSVReader`.
    private var rawData : List<Array<String>>

    // Variable to store column names which are rawData[0].
    private var columnNames : Array<String>

    ...

    init {
        // Create a CSVReader object
        val csvReader = CSVReader( InputStreamReader( context.assets.open( assetsFileName ) ) )

        // Call csvReader.readAll() which outputs the contents of the CSV in the form List<String[]>.
        // Every String[] corresponds to a single row.
        rawData = csvReader.readAll()

        // Get the column names.
        columnNames = getColumnNames()

        // Initialize variables like `numFeatures` and `numSamples`.
        // Also initialize `featureColumnData` by setting the keys as column names of this Hashmap.
        initTable()
    }