xd.avt: Download data from Alpha Vantage
In PMmisc: P&M Miscellaneous R Functions

This function will return time series data of financial securities from Alpha Vantage. Before using this function, a onetime registration is required to obtain a APIKEY, which is unique for users. Also, the key is valid for lifetime.

1	xd.avt(ticker,type,size="full",apikey,interval)

`ticker`	:the ticker for desired financial security. e.g. AAPL, MSFT
`type`	:data type; usable values: "TIME_SERIES_INTRADAY", "TIME_SERIES_DAILY", "TIME_SERIES_DAILY_ADJUSTED", "TIME_SERIES_WEEKLY", "TIME_SERIES_WEEKLY_ADJUSTED", "TIME_SERIES_MONTHLY", "TIME_SERIES_MONTHLY_ADJUSTED"
`size`	:the size of data downloaded; use "compact" for the latest 100 observations and "full" for at most the last 20 years as claimed by the website. However, most data only go back to Jan. 2000.
`apikey`	:a string that is obtained by a onetime registration
`interval`	:required for intraday data; usable values: "1min", "5min", "15min", "30min", "60min"

# All parameters are required to be strings
# The example is to download Ford Motor Company's daily adjusted price.
# The apikey here is just for demonstration purposes.
T <- xd.avt("T","TIME_SERIES_DAILY","full","QB45BDBGP0O7W8TB")