Fixes a bug where we'd fail to raise an error if the start/end of a
history window call don't aren't in the loader's calendar.
We were started dropping this error after a previous change swapped out
calls to `index.get_loc` with calls to `index.searchsorted` to avoid
creating hash tables in pandas.
Any DataFrame that's had `.loc` or `.iloc `called on it participates in
a cycle, which means they're not immediately garbage collected when they
go out of scope. This matters for pipeline results because they consume
multiple megabytes per column, which means that a pipeline result with
many columns can hold take up over 100MB. By manually breaking
DataFrame cycles, we can ensure that we never hold multiple pipeline
results in memory at once.
Pandas 0.18 doesn't like having null-ish values in categoricals. Fixing
this properly requires re-thinking the semantics for missing_value on
pipeline terms, so we're punting on that until after we've upgraded to
0.18.
- Fixes a warning on indexing with a float that ultimately came from
pd.Timedelta.total_seconds(). Adds ``timedelta_to_integral_seconds``
and ``timedelta_to_integral_minutes()`` functions and replaces various
usages of ``int(delta.total_seconds())`` with them.
- Fixes a warnings triggered in ``_create_daily_stats`` from
passing tz-aware datetimes to np.datetime64.
Adds `mask_time_between` to do more efficient comparisons between
pandas.DatetimeIndex and datetime.time objects.
This is used in the loader utils to more efficiently normalize datetimes
around the query time.
- Fixes an error where Modeling API data known as of the close of `day
N` would be shown to algorithms during `before_trading_start` as of
the close of the same day. Algorithms should now only receive data
during `before_trading_start/handle_data` that was known as of the
simulation time at which the function would be called.
- All Term instances now have a `mask` attribute that must be a `Filter`
or an instance of `AssetExists()`. `mask` can be used to specify that
a Factor should be computed in a manner that ignores the values that
were not `True` in the mask.
- Changed the interface for `FFCLoader.load_adjusted_array` and
`Term._compute` from `(columns, mask)`, with mask as a DataFrame, to
`(columns, dates, assets, mask)`, where mask is a numpy array. This
is primarily to avoid having to reconstruct extra DataFrames when
using masks produced by non `AssetExists` filters.
- Adds `BoundColumn.latest`, which gives the most-recently-known value
of a column.
Scott Sanderson