Downloads Symbols to specified env
from ‘finance.google.com’. This method is
not to be called directly, instead a call to
getSymbols(Symbols,src='google') will in
turn call this method. It is documented for the
sole purpose of highlighting the arguments
accepted, and to serve as a guide to creating
additional getSymbols ‘methods’.
Usage
getSymbols.google(Symbols,
env,
return.class = 'xts',
from = "2007-01-01",
to = Sys.Date(),
...)
Arguments
Symbols
a character vector specifying
the names of each symbol to be loaded
env
where to create objects. (.GlobalEnv)
return.class
class of returned object
from
Retrieve no earlier than this date
to
Retrieve though this date
...
additional parameters
Details
Meant to be called internally by getSymbols (see also).
One of a few currently defined methods for loading
data for use with quantmod. Essentially a
simple wrapper to the underlying
Google Finance site for historical data.
A word of warning. Google is the home of BETA, and historic data
is no exception. There is a BUG in practically all series that
include the dates Dec 29,30, and 31 of 2003. The data will show
the wrong date and corresponding prices. This essentially makes it
useless, but if they ever apply a fix the data is nice(r) than
Yahoo, in so much as it is all split adjusted and there is forty
years worth to be had. As long as you skip the holiday week of
2003. : )
Value
A call to getSymbols.google will load into the specified
environment one object for each
Symbol specified, with class defined
by return.class. Presently this may be ts,
its, zoo, xts, or timeSeries.
Note
As mentioned in the details section, a serious flaw exists within
the google database/SQL. A caution is issued when retrieving data
via this method if this particular error is encountered, but one
can only wonder what else may be wrong. Caveat emptor.
## Not run:
# All 3 getSymbols calls return the same
# MSFT to the global environment
# The last example is what NOT to do!
## Method #1
getSymbols('MSFT',src='google')
## Method #2
setDefaults(getSymbols,src='google')
# OR
setSymbolLookup(MSFT='google')
getSymbols('MSFT')
#########################################
## NOT RECOMMENDED!!!
#########################################
## Method #3
getSymbols.google('MSFT',verbose=TRUE,env=globalenv())
## End(Not run)