other details:
- also fixed grammatical errors in loader's status messages.
- converting the treasury curves to an ordered dict.
- moved to using a lambda for clarity as per @ehebert
- initializing calendar end dates to be midnight of current date in
- US/Eastern. Yahoo data isn't available until midnight eastern.
- added LSE reference rrules calendar (thanks to Edward Johns)
- added tests to verify LSE environment matches rrule calendar
- added a test to verify global environment behavior can be set.
- moved DailyReturn class to trading to eliminate circularity from
risk <-> trading.
- updated TradingEnvironment to be a context manager. This allows users
to run algorithms in individually isolated environments in one python
process. This is useful for managing multiple algorithms in a single
ipython notebook.
- added comments to explain behavior and useage of the global environment
Global state for the financial simulation environment is accessed through the
zipline.finance.trading module, which now contains a module variable:
environment.
Parameters are passed into an algorithm as a keyword argument, sim_params.
SimulationParameters creates a trading day index for the test period that
can be used to find trading days, calculate distance between trading days,
and other common operations. The sim params index is just selected from the
global state.
================
Details:
- adding delorean to the requirements.
- made index symbol a parameter for loading the benchmark data. changed
messagepack storage to be symbol specific.
- ported risk, performance, algorithm, transforms, batch transforms
and associated tests to use simulation parameters and global environment
- factory and sim factory use global state and sim params
- factory method parameter names now reflect the class expected
Algorithm returns and the risk calculations that depend on them now include
cash dividends. This commit does _not_ provide an API for user algorithms to
access dividends.
PerformanceTracker expects the dividend data to arrive as events, similar to
the way that Trades arrive. Dividends are expected to have adjusted payment
amounts that are inline with adjusted trades.
PerformanceTracker maintains state of all the unpaid dividends in the position
objects held in PerformancePeriod. Dividend objects contain all the relevant
dates (declared, ex, payment) as well as net and gross amounts. Dividends are
removed from the list as they are paid. Cash flow is not incremented until the
payment day. This creates the possibility of a dividend being owed but not
paid or realized before the end of a test. For example, a dividend with an
ex_date of today may have a pay date 2 weeks in the future. Right now the
algorithm does not receive any credit for unpaid dividends.
Tests cover buying/selling around the ex_date and payment_date, and checking
that the performance calculated is as expected.
The test factory was creating non-market days.
i.e. the date range spanned the weekend.
Using pandas' BDay frequency so that only business days are created.
This specific date range doesn't have holidays, so not accounting
for holidays in the factory.
Also, widens the range of the trading calendar to cover the test dates
generated by the factory which include 1990.
Previously the trading calendar began with 2002, meaning that holiday
and weekend adjustments with the data exercised by the factory did
not trigger when run with data in 1990.
This does increase the memory footprint of the tradingcalendar module.
However, only by a couple MB, so taking the hit there to enable
correct behavior.
Updated the search for treasury data when there is none for the
test end date.
It could be that the end date is not a trading day, or we could
just be missing treasury data. In either case, we try to recover
more gracefully now, by searching as far as possible and maybe
logging a warning.
Similarly, if there is no benchmark data for the test end date,
look for the next trading day. If we really have no data,
blow up with our own explicit exception, instead of overflowing
in our search for dates in the future.
By having run() use a capital_base member of the algorithm to
create the trading environment, the capital base should now be
configurable in the instantiation of the algorithm.
e.g.:
```
algo = LowCapitalBaseAlgorithm(capital_base=1000.0):
```
So that the zipline library can be used when installed to a
write-protected location, e.g. the global site-packages,
moving the download files to a directory in the user's path,
which should be writeable.
For now, choosing a ~/.zipline/data location.
Hopefully, this helps ease ramp up time for developing against
market data, without us distributing the data.
We do a check for the data when attempting to read the msgpack
files, if they don't exist the loader makes a web request and
retrieves and serializes the data for the user.
Provides a loader for:
- curves from data.treasury.gov
- benchmarks from Yahoo! Finance
Adds dependency of requests library in dev requirements.
Mostly whitespace, line width and other spacing changes.
Also, removes use of deprecated has_key in favor of `in`
Going forward new patches should pass running `flake8` before
submission.
fawce