Programming performance/JasonWoof Ruby

Language: ruby

Experience level with ruby: beginner

Time taken: 50 minutes

Notes: The code is crappy for two reasons: 1) I don't know ruby very well, 2) I was racing. I spent a bunch of time looking up how to do basic things like read a line. A skilled ruby programmer could probably do this in 15 minutes.

#!/usr/bin/ruby

$verbose = false

$bank = 10000.00
$stocks = []


file = File.new('gspc.txt')
file.readline

data = file.readlines
$last_close = data.pop.split(/[ \n]/)[6].to_f
data = data.reverse

data.each do |line|
    words = line.split(/[ \n]/)
    $close = words[6].to_f
    if $verbose
        print "bank: #{$bank.to_s}\n"
        print "close: #{$close.to_s}\n";
        print 'change: ' + ((($close - $last_close) / $last_close) * 100.0).to_s + "%\n"
    end
    if ($close - $last_close) / $last_close < -0.03
        $stocks.push([$close, ($bank / 10) / $close])
        if $verbose
            print 'bought ' + (($bank / 10) / $close).to_s + " shares at #{$close}\n"
            print 'bank: ' + $bank.to_s + "\n"
        end
        $bank *= 0.9;
    end
    thresh = $close / 1.06
    new_stocks = [];
    $stocks.each do |row|
        held_close = row[0]
        held_count = row[1]
        if(held_close <= thresh)
            $bank += held_count * $close;
            if $verbose
                print "sold #{held_count} shares that were bought at #{held_close.to_s}\n"
                print "bank: #{$bank}\n"
            end
        else
            new_stocks.push [held_close, held_count]
        end
    end
    $stocks = new_stocks
    $last_close = $close
end

$stocks.each do |row|
    held_close = row[0]
    held_count = row[1] 
    $bank += held_count * $close;
end

print 'bank: ' + $bank.to_s + "\n"

exit;