The purpose of this gem is to interface with Yahoo Finance, and also do some basic stock related calculations. pbyf stands for Pause Break Yahoo Finance

First install the gem and have require 'pbyf' in your app

Right now you get access to two classes, PBYF and HistoricalQuote

PBYF.get_quote str_of_stocks, str_of_options

This method must be passed two strings, one being a correctly formatted string of Yahoo Finance stock symbols ('GOOG,BUD' will give google and budweiser stock arrays back). The second is a correctly formatted string of options ('nsl1op' should do something I think). Options are here. You will receive back an array of arrays with the data.

PBYF.get_hist_quote str_of_stock, from_date, to_date, interval

Similar to above method, but can only do one stock at a time. Interval is like day, week, month (passed as d, w, m,). Dates should be string format like '4-22-2012'

HistoricalQuote is an object that is instantiated with 'HistoricalQuote.new(str_of_stock, from_date, to_date, interval = d)' similar to the method above

get_hist_column(column)

returns an array of a column of the data

stochastic_oscillator

returns an array of the stocastic oscillator for the data set, beginning 3 days from the from_date the object was initialized with

find_k

returns an array of %K, which is used to calc the stochastic oscillator. Not sure if its useful for other things so it is a public method

Some methods have been added to the Array class as well for using with your stock data macd(short, long) returns the Moving Average Convergence Divergence, using the exponential moving average of the data. This is set to using closing data by default if you leave out the column parameter.

exp_moving_average(interval)

When performed on an array it will return an array with the Exponential Moving Averages for that array, starting with array[interval]. i.e. choosing an interval of 5 will return an array which has 5 fewer elements than the original

moving_average(interval)

Like the above but for simple moving averages

average

This returns an average of all elements in the array as a float

macd(short,long)

Returns an array with all the MACD, starting wit the element array[long]. You pass the short exponential moving average interval and the long exponential moving average interval