I'm using HTTParty to connect to stockfighter.io 's API and getting a quote of a stock, which I then extract a price per share from and append it to the end of the $averageArr array.
I'm trying to average the last five values of a constantly updating array, $averageArr, and so I thought I would make a variable sum set it to zero, add those last five values to it and then divide it by 5 to get a dynamic and changing average.
Here's my code:
require 'rubygems'
require 'httparty'
require 'json'
apikey = 'API_KEY_FOR_LOGIN_HERE'
venue = "VENUEX"
stock = "FOOBAR"
base_url = "https://api.stockfighter.io/ob/api"
account = "MY_ACCOUNT_HERE"
$averageArr = []
$counter = 0
$currAve = 0
def getQuote(stock, venue, account)
response = HTTParty.get("https://api.stockfighter.io/ob/api/venues/#{venue}/stocks/#{stock}/quote")
orderbook = response.parsed_response
puts orderbook["ok"]
return orderbook["last"]
puts orderbook["lastTrade"]
end
def getAverage(stock, venue, account)
$averageArr.push(getQuote(stock, venue, account))
$counter += 1
if $counter > 5
sum = 0
#line 43
for i in 1..5 do
# this one is line 45
sum += $averageArr[$averageArr.count - i]
end
return sum/5
$currAve = sum/5
else
return 'WAITING FOR QUOTE. CURRENT:'
end
end
# line 62
for i in 1..10 do
# line 64
getAverage(stock, venue, account)
if $counter > 5
if getQuote(stock, venue, account) < $currAve - 25 and numShares < 999
order = {
"account" => account,
"venue" => venue,
"symbol" => stock,
"price" => 1, #$250.00 -- probably ludicrously high
"qty" => 1,
"direction" => "buy",
"orderType" => "market" # See the order docs for what a limit order is
}
response = HTTParty.post("#{base_url}/venues/#{venue}/stocks/#{stock}/orders",
:body => JSON.dump(order),
:headers => {"X-Starfighter-Authorization" => apikey}
)
elsif getQuote(stock, venue, account) > $currAve + 25 and numShares > 0
order = {
"account" => account,
"venue" => venue,
"symbol" => stock,
"price" => 1, #$250.00 -- probably ludicrously high
"qty" => 1,
"direction" => "sell",
"orderType" => "market" # See the order docs for what a limit order is
}
response = HTTParty.post("#{base_url}/venues/#{venue}/stocks/#{stock}/orders",
:body => JSON.dump(order),
:headers => {"X-Starfighter-Authorization" => apikey}
)
end
end
end
I've been having difficulty with line 45 (commented), in which I get errors about FixNum and nil:
/Users/kaichristensen/Dropbox/Kai/Stockfighter/level_three_selling.rb:45:in `+': nil can't be coerced into Fixnum (TypeError)
from /Users/kaichristensen/Dropbox/Kai/Stockfighter/level_three_selling.rb:45:in `block in getAverage'
from /Users/kaichristensen/Dropbox/Kai/Stockfighter/level_three_selling.rb:43:in `each'
from /Users/kaichristensen/Dropbox/Kai/Stockfighter/level_three_selling.rb:43:in `getAverage'
from /Users/kaichristensen/Dropbox/Kai/Stockfighter/level_three_selling.rb:64:in `block in <main>'
from /Users/kaichristensen/Dropbox/Kai/Stockfighter/level_three_selling.rb:62:in `each'
from /Users/kaichristensen/Dropbox/Kai/Stockfighter/level_three_selling.rb:62:in `<main>'
I might be trying to access and index out of scope on the array, but that doesn't seem to be the problem. Any help would be appreciated.
Your syntax is fine. The problem is that your methods are not validating data.
a += b expands to a = a + b, which will throw the error you're facing when b is nil.
You need to make sure that getQuote always returns a number, or cast whatever you want to average into a number before performing mathematical operations.
For the former, you can change return orderbook["last"] to return orderbook["last"].to_f
For the latter, sum += $averageArr[$averageArr.count - i].to_f