Adds four new methods to the Zipline API that can be used as circuit-breakers
to interrupt the execution of an algorithm. The API methods are:
`set_max_position_size`
`set_max_order_size`
`set_max_order_count`
`set_long_only`
Internally, these methods are implemented by each registering a TradingControl
callback object with the TradingAlgorithm. During
TradingAlgorithm.__validate_order_params (and thus before any side-effects of
the order call occur), each callback's `validate` method is called with
information about the order to be placed and the algorithm's current state,
raising an exception if the callback detects that an error condition has been breached.
Add a test case in test_algorithms to verify that appropriate exceptions are
thrown if an algorithm makes a call to the order api with a stop/limit price
and a style.
Add `style` parameter to order_value, order_percent, order_target,
order_target_percent, and order_target_value methods. The style parameter is
forwarded to the underlying call to `order`.
Fixes an issue where very low limit prices were being rounded to 0.0 and
effectively resulting in market orders. Adds an explicit check to test for
this behavior.
Adds a test algorithm that tries to buy with very high limit prices/very low
stop prices and tries to sell with very low limit prices/very high stop prices.
A symbol() lookup feature was added to Quantopian.
By adding the same API function to zipline we can
make copy&pasting of a zipline algo to Quantopian
easier.
When running with minutely emissions the simulator would report to the
user that it simulated 'n - 1' days (where n is the number of days
specified in the simulation params). Now the correct number of trading
days are reported as being simulated.
This is a step towards the goal of uniting Quantopian scripts
and zipline.
To make the syntax of zipline identical to Quantopian
we break out the API methods (like order) and turn them into
functions. To access the algo object we add a thread local reference
to the current algorithm that is accessed in the API functions.
TradingAlgorithm now takes either a string or two functions
(initialize and handle_data) that it executes.
Use api method decorator for methods available in algoscript.
Ported appropriate algorithm tests from internal code.
To help prevent algorithms from operating on positions that are
not in the existing universe of stocks.
Formerly, iterating over positions would return positions for stocks
which had zero shares held. (Where an explicit check in algorithm
code for `pos.amount != 0` could prevent from using a non-existent
position.)
Use the six module to import functions and types that are
consistent between Python 2 and 3, so that one code base can
support both versions.
- Use integer types instead of int and long.
- Use string_types instead of basestring.
- Account for iteritems, itervalues, iterkeys.
- Use six.moves for filter and zip, reduce
- Use compatible bytes for md5 hasher.
- xrange and range
- Use `print()` function for all print calls
- Fix strip and format calls that were on the outside of the
print function for some reason.
(Which were breaking in Python 3 because of print returning None.)
- Remove commented out print calls.
Before the change to the RollingPanel, window_length
specified the number of days that should be in a window.
The previous commit broke this if data was minute resolution.
By passing bar='minute' to the batch_transform we internally
multiply the window_length by 60*6.5 to have a full day.
Also adds a (still rudamentary) test for batch_transform
with minute data.
- moved Order and Blotter to zipline.finance.blotter
- moved order method from AlgoSimulator to Blotter
- eliminated the set_order method in algorithm
- moved blotter to the algorithm
- repeated calls with the same data window do not update batch transform
windows.
- repeated calls with the same data and same supplemental parameters do
not update batch transform results
- repeated calls with the same data and different supplemental params
do update batch transform results
- removed use_panel
- default for refresh_period is now 0
- refresh_period will only affect the recreation of the datapanel
- user's transform method is invoked on every call to batch transform
Uses a method called 'record' that provides a key value,
instead of providing keys to extract from context.
The variables are stored internally to the algorithm in a dictionary,
and not just stared as a property of the algorithm.
Main intent behind this change is to make the API more user friendly,
since the previous recorded_variables relies on the value to be set
in the algorithms context/self, the hope is that only having to use
the `record` method means less moving pieces and a more understandable
API.
i.e., instead of:
```
def initialize(self):
recorded_variables('foo', bar')
def handle_data(self, data):
self.foo = 1
self.bar = 2
```
The API is now:
```
def initialize(self):
pass
def handle_data(self, data):
self.record(foo=1, bar=2)
```
The recent change to the creation of the data panel ended up with
a panel with the dtype of 'object', which was causing numpy ufuncs
like `log` to crash out on an `AttributeError`.
This forces all frames in the panel to use a dtype of 'float',
we may want to look at seeting a dtype on a frame by frame basis,
e.g. 'volume' may more accurately be 'int'.
Takes the value set for a variable on handle_data and records it,
e.g.:
```
def initialize(self):
self.incr = 0
self.record_variables(['incr'])
def handle_data(self, data):
self.incr += 1
```
Would record a variable of `incr`.
Emits the recorded variables as part of the daily performance.
This batch combins work from:
Thomas Wiecki <thomas.wiecki@gmail.com> (@twiecki)
fawce <fawce@quantopian.com> (@fawce)
Starting down the path of making the portfolio completely read-only
with respect to the handle_data in algo.
The portfolio should only be changed during the course of running
the algorithm by the simulator.
This doesn't do a 100% protection, i.e. an algo could use _portfolio,
or the set_attr property, but hoping this helps guides algo writing
to treat the portfolio as read-only.
Scott Sanderson