Done with all the task #3
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| object DataMunging { | ||
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| def main(args: Array[String]) ={ |
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You can remove def main(args: Array[String]) by just extending App, that is, object DataMunging extends App
| source.close() | ||
| } | ||
| // | ||
| // def getSourceData(filename: String): BufferedSource = { |
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You can delete commented out code to keep your code clean
| // return Source.fromFile(filename) | ||
| // } | ||
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| def find_min(data: List[(String, Double)]): (String, Double)= { |
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Nice job factoring out this common code 👍
| getMinGoalDiff() | ||
| } | ||
| def getMinSpread() = { | ||
| val source = Source.fromFile("weather.dat") |
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You could also factor out
- the code to fetch all the lines in the function, because that is common to both getMinSpread() and getMinGoalDiff().
- filter out the header and the lines with "-----" and the blank line in this function.
- and you tokenise (split) by space.
That is:
def getLines(val fileName:String):List[Array[String]] = {
val source = Source.fromFile(fileName)
val lines = source.getLines.toList
source.close
lines.drop(0)
.filter(line=> !line.contains("-----"))
.filter(line => !line.trim.isEmpty)
.map(_.split("\\s+"))
}
| .map(_.split("\\s+")) // split each line on white space | ||
| .map(x =>(x(2), x(7).toDouble - x(9).toDouble)) // select team and different between f and a | ||
| val team = find_min(teams) | ||
| println(s"2: the team with the smallest difference for and against goal is ${team._1} with a difference of ${team._2} degrees") |
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Nice touch with the string interpolation 👍
| .map(_.split("\\s+")) // split on regex white space | ||
| .map(x => (x(1), x(2).stripSuffix("*").toDouble-x(3).stripSuffix("*").toDouble)) //clean the recourds as somelines have * and aslo conver to double | ||
| val min_spread = find_min(spread) // get minimum spread | ||
| println(s"1: the day with the smallest temparature spread is day ${min_spread._1} with a spread of ${min_spread._2} degrees") |
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println at this point is okay. However your getMinSpread() function can be more testable with a unit test if you make it return the actual spread. In other words, making it 'a pure function without side-effects' .
The println can be cone in the main method. So your main method would look like:
def main(args: Array[String]) ={
val minSpread = getLines("weather.dat"). getMinSpread
println(s"1: the day with the smallest temparature spread is day ${minSpread._1} with a spread of ${minSpread._2} degrees")
val team = getLines("football.dat").getMinGoalDiff()
println(s"2: the team with the smallest difference for and against goal is ${team._1} with a difference of ${team._2} degrees")
}
| .drop(2) //the first line is a header and second line is a blank space so skip those lines here. | ||
| .map(_.split("\\s+")) // split on regex white space | ||
| .map(x => (x(1), x(2).stripSuffix("*").toDouble-x(3).stripSuffix("*").toDouble)) //clean the recourds as somelines have * and aslo conver to double | ||
| val min_spread = find_min(spread) // get minimum spread |
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Scala style guide usually goes with camelCase variable names like minSpread, rather than having underscores like min_spread
| def getMinGoalDiff() = { | ||
| val source = Source.fromFile("football.dat") //get file access object | ||
| val teams = source.getLines.toList | ||
| .drop(1) //drop the header |
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If you implement getLines the way I suggest, getMinGoalDiff() becomes
def getMinGoalDiff(line: Array[String):(String, Double).
Also lines 22 to 26 will no longer be needed.
| def find_min(data: List[(String, Double)]): (String, Double)= { | ||
| return data.reduceLeft((x,y) => if (x._2 < y._2) x else y) | ||
| } | ||
| } |
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Overall, very very good effort 👍 👍 . For someone new to Scala, you have done a great job!
I am done with all the task.
Though i know i can still do some refactoring ( task 3) ... will try to improve on it soon.
Your comments are welcome