// Part 2 about Buy-Low-Sell-High using Yahoo Financial Data+
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//===========================================================+
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+
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// (1) Complete the function that is given a list of floats+
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// and calculuates the indices for when to buy the commodity +
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// and when to sell+
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+
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def trade_times(xs: List[Double]): (Int, Int) = {+
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  val low = xs.min+
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  val low_index = xs.indexOf(low)+
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  val rest = xs.drop(low_index)+
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  val high = rest.max+
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  val high_index = rest.indexOf(high)+
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  (low_index, low_index + high_index)+
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}+
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+
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val prices = List(28.0, 18.0, 20.0, 26.0, 24.0)+
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assert(trade_times(prices) == (1, 3), "the trade_times test fails")+
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+
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+
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// (2) Complete the ``get webpage'' function that takes a+
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// a stock symbol as argument and queries the Yahoo server+
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// at+
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//      http://ichart.yahoo.com/table.csv?s=<<insert stock symbol>>+
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// +
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// This servive returns a CSV-list that needs to be separated into+
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// a list of strings.+
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+
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import io.Source+
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import scala.util._+
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+
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def get_yahoo_page(symbol: String): List[String] = {+
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  val url = """http://ichart.yahoo.com/table.csv?s=""" + symbol+
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  Try(Source.fromURL(url)("ISO-8859-1").getLines.toList).+
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    getOrElse { println(s"  Problem with: $url"); List() }+
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}+
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+
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// (3) Complete the function that processes the CSV list+
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// extracting the dates and anjusted close prices. The+
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// prices need to be transformed into Doubles.+
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+
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def process_page(symbol: String): List[(String, Double)] = {+
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  get_yahoo_page(symbol).drop(1).map(_.split(",").toList).map((xs) => (xs(0), xs(6).toDouble))+
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}+
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+
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+
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// (4) Complete the query_company function that obtains the+
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// processed CSV-list for a stock symbol. It should return+
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// the dates for when to buy and sell the stocks of that company.+
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+
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def query_company(symbol: String): (String, String) = {+
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  val list = process_page(symbol).reverse+
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  val (tbuy, tsell) = trade_times(list.map(_._2))+
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  (list(tbuy)._1, list(tsell)._1)+
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}+
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+
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//query_company("GOOG")+
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+
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val indices = List("GOOG", "AAPL", "MSFT", "IBM", "FB", "YHOO", "AMZN", "BIDU")+
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+
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for (name <- indices) {+
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  val times = query_company(name)+
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  println(s"Buy ${name} on ${times._1} and sell on ${times._2}")+
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}+
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+
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+
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+
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/*+
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scala trade.scala 2> /dev/null || echo "command1 borked it"+
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+
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command1+
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if [ $? -ne 0 ]; then+
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    echo "command1 borked it"+
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fi+
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*/+
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