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.
Changes these tests to use market_aware==True, so that unit tests
follow the same code path as actual execution.
All use of EventWindows against data follows market_aware behavior.
These tests are the only use of market_aware==False, so heading
down the path of removing market aware completely.
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.
These tests ensure that there are three, not two, empty values
at the beginning of the transform.
Also, ensures that we are using a window length of 3 on the tests.
So that wordings of errors,etc. match the window length.
Though the addition of tracking mulitple values in the window
is powerful, the changes broke behavior of existing algorithms
by changing method signatures and names.
So temporarily reverting these changes, to be pulled back in when
a way to have the multiple fields tracked with the existing API
is written, or a cutover of the API is figured out and determined.
The latest flake8 release in now 1.5, which pulls in pep8: 1.3.4a0
The upgrade pep8 has changes to what it picks up as lint.
Making code base compatible, so that new devs can install pep8
from PyPI and not have friction over the version difference.
Currently using these ignores in the config file:
```
[pep8]
ignore = E124,E125,E126
```
Ignoring these since they are difficult to squash while maintaining
an 80 char line length, and appear spurious.
Should address later.
Updates Travis config, README, and pip requirements to reflect change.
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