Feature Extraction using Zone Based

ZonaFE.kt

package com.github.putraxor

/**
 * Feature Extraction using Zone Based
 */
object ZonaFE {

    /**
     * Extract feature from matrix
     * [z] number of zones
     * [matrix] matrix to be extracted
     * @return double array of zoned density
     */
    fun extract(z: Int, matrix: List<List<Int>>): DoubleArray {
        val zone = mutableListOf<List<Int>>()
        val r = matrix[0].size / z
        for (row in 0 until z) {
            for (col in 0 until z) {
                val rowStart = row * r
                val colStart = col * r
                val temp = mutableListOf<Int>()
                for (i in 0 until r) {
                    (0 until r).mapTo(temp) { matrix[rowStart + i][colStart + it] }
                }
                zone.add(temp)
            }
        }
        val density = mutableListOf<Double>()
        zone.forEach { density.add(it.sum() / it.size.toDouble()) }
        return density.toDoubleArray()
    }
}