[R-SIG-Finance] Quantstrat - extracting current symbol

[Brian G. Peterson]

You asked:

> The best way to get the attribute then, would be to call
> 'getInstrument(symbol)$newAttribute'?

Yes.

Here's an example:

###

getInstrument('ESH8')

# primary_id        :"ES_H8"
# currency          :"USD"
# multiplier        :50
# tick_size         :0.25
# identifiers       :List of 2
# ..$ X.RIC:"ESH8"
# ..$ local:"ESH8"
# type              :"future_series" "future"
# root_id           :"ES"
# suffix_id         :"H8"
# expires           :"2018-03-16"
# exchange          :"GLOBEX"
# underlying_id     :"ES"
# exchange_id       :"ES"
# series_description:"E-mini S&P 500 2018-03"
# timeZoneId        :"CTT"
# tradingHours      :"T15:30:00/T16:30:00" "T17:00:00/T15:15:00"
# liquidHours       :"T08:30:00/T15:15:00"
# primary_start     :"08:30:00"
# primary_end       :"15:15:00"
# electronic_start  :"15:30:00"
# electronic_end    :"16:30:00"
# validExchanges    :"GLOBEX" "MIBSX"
# updated           : POSIXct, format: "2012-02-27 15:26:53.52408"
# contract_month    :"2018-03"

getInstrument('ESH8')$tick_size
#  [1] 0.25

###

So the method you ask about works just fine.  If you're going to be
extracting multiple attributes, it would make sense to call
getInstrument only once to minimize the search time (we have many
thousands of instruments in our instrument environment) and then take
the attributes you want out of your local copy.

Regards,

Brian

On Fri, 2017-05-12 at 12:07 +0200, Oskar Gottlieb wrote:
> Hi Brian,
> 
> Thanks for the quick reply!
> I was aware of the instrument objects, I just did not know there were
> the instrument_attr(), instrument.table() functions. This solves the
> need for external meta info dataframe, which is extremely convinient.
> The best way to get the attribute then, would be to call
> 'getInstrument(symbol)$newAttribute'?
> 
> About add.indicator - I did a poor job explaining what I was trying
> to achieve, but it's exactly what you're saying. I will create a new
> indicator function, which will get some metadata from the instrument
> and all of that will be handled inside the indicator function, there
> is no need to pass it as a parameter to the add.indicator function.
> 
> Thanks again!
> Oskar
> 
> 2017-05-12 11:16 GMT+02:00 Brian G. Peterson <brian at braverock.com>:
> 
> > On 05/12/2017 03:58 AM, Oskar Gottlieb wrote:
> > 
> > > I have multiple symbols (futures contracts) of one product and I would
> > > like
> > > to access a data frame with their meta information. I would then parse the
> > > meta info into an add.indicator argument list. Is there a function, which
> > > would return the current symbol over which we are looping?
> > > 
> > 
> > quantstrat would expect the metadata for these symbols to be in
> > FinancialInstrument, not in a data.frame.  That is where quantstrat and
> > blotter expect to get things like tick size, multiplier, expiration date,
> > and currency for each instrument.
> > 
> > Inside quantstrat, there will always be a 'symbol' variable which you
> > could access to find out what symbol is currently being processed (unless
> > we're in a rebalancing rule, when that doesn't apply).
> > 
> > What I would recommend is to put all your instrument metadata in
> > FinancialInstrument (since that is what it is for) and have your indicator
> > and signal functions access that data with
> > 
> > getInstrument(symbol)
> > 
> > To further guess at what you're trying to do, you talk about using this
> > list for add.indicator.  I don't understand what you're trying to do with
> > that statement.  The strategy object is a specification of how the strategy
> > will work.  The indicators, signals, and rules should all work on the
> > mktdata passed to them by the applyStrategy function (and inside that by
> > applyIndicators, applySignals, applyRules).  So any call to add.indicator
> > should be generic for the entire strategy specification.
> > 
> > If you wanted an indicator to do something different based on tenor or
> > days to expiration, for example, you'd handle that inside the indicator
> > function, not as parameters to the call to add.indicator. (probably after
> > calling getInstrument to get the metadata, as described above).
> > 
> > If this hasn't answered your question, perhaps you could follow up with
> > something more specific including a *minimal* example.
> > 
> > Regards,
> > 
> > Brian
> > 
> > --
> > Brian G. Peterson
> > http://braverock.com/brian/
> > Ph: 773-459-4973
> > IM: bgpbraverock
> > 
> > _______________________________________________
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