def calculateValueOf()

in src/main/groovy/console/MortgageCalculator.groovy [51:91]

• 40 lines of code
• 7 McCabe index (conditional complexity)

def calculateValueOf(valueToCalculate) {
    def result = 0
    def principal = variables["Amount of mortgage"]
    def interest = variables["Annual interest rate (%)"] / 1200
    def months = variables["Loan duration (months)"]
    def payment = variables["Monthly payments"]

    switch (valueToCalculate) {
    case "Amount of mortgage":
        result = 1 + interest
        result = 1/Math.pow(result,months)
        result = ((1-result)/interest) * payment
        break           
    case "Loan duration (months)":
        result = (1 - (principal * interest / payment))
        result = Math.log(result)
        result = - result / Math.log(1 + interest)  
        break
    case "Monthly payments":
        result = 1 + interest
        result = 1 / Math.pow(result,months)
        result = (principal * interest) / (1 - result)
        break          
    case "Annual interest rate (%)":
        result = payment / principal
        def diff = 100; def accuracy = 0.00001; def maxIterations = 1000
        def index = 0
        while ((diff > accuracy) && (index < maxIterations)) {
            def temp = result
            def numerator = (principal * temp / payment) + Math.pow((1 + temp), -months) - 1
            def denominator= (principal / payment) - months * Math.pow((1 + temp), (-months - 1))
            result = temp - (numerator / denominator)
            diff = result - temp
            diff = Math.abs(diff)
            index++
        }
        result *= 1200
        break           
    }
    return result
}