LinearChartHelper.kt

/**
 * Calculates the Y pixel coordinate for a given transaction rate.
 *
 * @param higherTransactionRateValue the highest rate value in the whole list of transactions.
 * @param currentTransactionRate the current transaction RATE while iterating the list of transactions.
 * @param canvasHeight the canvas HEIGHT for draw the linear chart.
 *
 * @return [Float] Y coordinate for a transaction rate.
 */
private fun calculateYCoordinate(
    higherTransactionRateValue: Double,
    currentTransactionRate: Double,
    canvasHeight: Float
): Float {
    val maxAndCurrentValueDifference = (higherTransactionRateValue - currentTransactionRate)
        .toFloat()
    val relativePercentageOfScreen = (canvasHeight / higherTransactionRateValue)
        .toFloat()
    return maxAndCurrentValueDifference * relativePercentageOfScreen
}