How to separate an variable array into smaller arrays using swift

Question

I have a question I cannot figure out. Is there an easier way to separate an array into other arrays. In the code below I do a Trace route and filter out everything except the ping rates.

Then I break down that array into individual nodes. The only downside is if it only takes 2 hops then I get an error, "fatal error: Index out of range." because I have it set up to create 15 node arrays. I have also tried putting ..

let count = pingRate.count
if count < 15 {
aNodeArray += pingRate[14]
}

Is there an easier way? I wish there was a way to do a .count and then populate the Int the is required on each node.

let task = Process()
    task.launchPath = "/bin/sh"
    task.arguments = ["-c", "traceroute -nm 15 -q 1 8.8.8.8"]

    let pipe = Pipe()
    task.standardOutput = pipe
    task.launch()
    let data = pipe.fileHandleForReading.readDataToEndOfFile()
    let output = NSString(data: data, encoding: String.Encoding.utf8.rawValue) as! String
    var array = output.components(separatedBy: " ")

    array = array.filter({ $0.contains(".")})
    let pingRate: [[Double]] = array.enumerated().filter({ index, _ in
        index % 2 != 0
    }).map { [Double($0.1)!] }
    let aNode = pingRate[0]
    let bNode = pingRate[1]
    let cNode = pingRate[2]
    let dNode = pingRate[3]
    let eNode = pingRate[4]

    aNodeArray += aNode
    bNodeArray += bNode
    cNodeArray += cNode
    dNodeArray += dNode
    eNodeArray += eNode

Once I get that done then I sort and find the min, max, and average.

    let sorted = aNodeArray.sorted()
    let numbers = sorted
    print(numbers)
    let min = numbers[0]

    var sum = 0 as Double
    for number in numbers {
        sum += number
    }
    let mean = Double(sum) /
        Double (numbers.count)
    let x = mean
    let avg = round(1000.0 * x) / 1000.0
    let maxBR = numbers.last! as Double
    let max = round(1000.0 * maxBR) / 1000.0

    print(min)
    print(max)
    print(avg)

Edit

I did stumble upon chunks and stride from... Swift: what is the right way to split up a [String] resulting in a [[String]] with a given subarray size?

I am trying to figure a way to implement that for my needs

Edit

And looking at that code. Can anyone tell me why I get the Color spinning wheel until the process() is finished?

Price Ringo · Answer 1 · 2017-03-31T01:56:35.203

I know that there are more efficient algorithms to calculate your ping rate statistics but the code below should do the job.

let task = Process()
task.launchPath = "/bin/sh"
task.arguments = ["-c", "traceroute -nm 15 -q 1 8.8.8.8"]
let pipe = Pipe()
task.standardOutput = pipe
task.launch()

let data = pipe.fileHandleForReading.readDataToEndOfFile()
guard
  let pingRates = String(data: data, encoding: .utf8)?
    .components(separatedBy: " ")
    .filter({ $0.contains(".") })
    .flatMap({ Double($0) }),
  pingRates.count > 0
else {
  return
}
print("ping rate(min) = \(pingRates.min()!.rounded())")
print("ping rate(max) = \(pingRates.max()!.rounded())")
print("ping rate(avg) = \((pingRates.reduce(0, +) / Double(pingRates.count)).rounded())")

The trick to eliminating the IP addresses in your output is to let Double.init fail on them and then flatMap will remove those nil values.

How to separate an variable array into smaller arrays using swift

1 Answers1