def test_limit_to_span(self):
evs = [
esal.Event(esal.Interval(1, 9), 'a', 1),
]
expected = [
(esal.Interval(3, 7), 1),
]
actual = list(events.periods(evs, 3, 7))
self.assertEqual(expected, actual)
def test_min_len_limit_to_span(self):
evs = [
esal.Event(esal.Interval(1, 1), 'a', 1),
]
expected = [
(esal.Interval(2, 5), 1),
]
actual = list(events.periods(evs, 2, 5, min_len=7))
self.assertEqual(expected, actual)
def test_backoff_too_much(self):
evs = [
esal.Event(esal.Interval(1, 1), 'a', 1),
esal.Event(esal.Interval(5, 5), 'a', 2),
]
expected = [
(esal.Interval(1, 1), 1),
(esal.Interval(5, 9), 2),
]
actual = list(events.periods(evs, 1, 9, min_len=5, backoff=5))
self.assertEqual(expected, actual)
def test_backoff_drop_empty_zero_val(self):
evs = [
esal.Event(esal.Interval(1, 2), 'a', 1),
esal.Event(esal.Interval(3, 4), 'a', 1),
]
expected = [
(esal.Interval(1, 2), 1),
(esal.Interval(3, 4), 1),
]
actual = list(events.periods(evs, 0, 4, backoff=1))
self.assertEqual(expected, actual)
def test_fill_span(self):
evs = [
esal.Event(esal.Interval(2, 3), 'a', 1),
]
expected = [
(esal.Interval(1, 2), 0),
(esal.Interval(2, 3), 1),
(esal.Interval(3, 4), 0),
]
actual = list(events.periods(evs, 1, 4))
self.assertEqual(expected, actual)
def test_backoff_non_overlapping(self):
evs = [
esal.Event(esal.Interval(1, 1), 'a', 1),
esal.Event(esal.Interval(5, 5), 'a', 2),
]
expected = [
(esal.Interval(1, 3), 1),
(esal.Interval(5, 8), 2),
]
actual = list(events.periods(evs, 1, 8, min_len=3, backoff=2))
self.assertEqual(expected, actual)
def test_empty(self):
evs = []
expected = [
(esal.Interval(0, 9), 0),
]
actual = list(events.periods(evs, 0, 9))
self.assertEqual(expected, actual)
def test_zero_values(self):
evs = [
esal.Event(esal.Interval(1, 7), 'a', '0'),
]
expected = [
(esal.Interval(0, 1), 0),
(esal.Interval(1, 7), '0'),
(esal.Interval(7, 9), 0),
]
actual = list(events.periods(evs, 0, 9, zero_values=(0, )))
self.assertEqual(expected, actual)
expected = [
(esal.Interval(0, 9), 0),
]
actual = list(events.periods(evs, 0, 9, zero_values=('0', )))
self.assertEqual(expected, actual)
def setUp(self):
ev = esal.Event
itvl1 = esal.Interval('2019-04-09', '2019-04-10')
itvl2 = esal.Interval('2019-04-09')
self.ev_seq = esal.EventSequence(
events=[
ev(itvl1, ('mx', '4'), ('lo', None)),
ev(itvl1, ('mx', '4'), ('hi', None)),
ev(itvl1, ('mx', '5'), ('lo', None)),
ev(itvl1, ('mx', '8'), ('hi', None)),
ev(itvl1, ('mx', '0'), ('lo', None)),
ev(itvl1, ('mx', '2'), ('ok', None)),
ev(itvl1, ('mx', '1'), ('ok', None)),
ev(itvl1, ('mx', '8'), ('ok', None)),
ev(itvl2, ('dx', '2'), (None, None)),
ev(itvl2, ('dx', '0'), (None, None)),
ev(itvl2, ('dx', '7'), (None, None)),
ev(itvl2, ('dx', '2'), (None, None)),
ev(itvl2, ('dx', '1'), (None, None)),
ev(itvl2, ('dx', '3'), (None, None)),
ev(itvl1, ('rx', '0'), (None, None)),
ev(itvl1, ('rx', '5'), (None, None)),
ev(itvl1, ('rx', '0'), (None, None)),
ev(itvl1, ('rx', '4'), (None, None)),
ev(itvl1, ('rx', '1'), (None, None)),
ev(itvl1, ('px', '3'), (None, None)),
ev(itvl1, ('px', '2'), (None, None)),
ev(itvl1, ('px', '5'), (None, None)),
ev(itvl1, ('px', '2'), (None, None)),
ev(itvl1, ('ox', '0'), (None, None)),
ev(itvl1, ('ox', '6'), (None, None)),
ev(itvl1, ('vx', '1'), (None, None)),
ev(itvl1, ('vx', '1'), (None, None)),
ev(itvl1, ('xx', None), (None, None)),
],
facts=[
(('bx', 'dob'), '1949-04-09'),
(('bx', 'ethn'), '1'),
(('bx', 'gndr'), 'M'),
(('bx', 'race'), '2'),
(('hx', 'cancer-father'), 'yes'),
(('hx', 'cancer-mother'), 'no'),
],
id=808186755,
)
def sequence(
event_records,
event_sequence_id=None,
header_nm2idx=header_nm2idx,
):
"""
Construct an event sequence from the given records and return it.
Any record in which the fields `lo` and `hi` are both `None` is
treated as a fact. All other records are treated as events.
event_records:
Iterable of event records where each record is an indexable
collection of values.
event_sequence_id:
ID for constructed event sequence.
header_nm2idx:
Mapping of event record field names to their indices in the
record. Must include at least the following names: id, lo, hi,
cat, typ, val, jsn.
"""
# Unpack indices of event record fields
id_idx = header_nm2idx['id']
lo_idx = header_nm2idx['lo']
hi_idx = header_nm2idx['hi']
cat_idx = header_nm2idx['cat']
typ_idx = header_nm2idx['typ']
val_idx = header_nm2idx['val']
jsn_idx = header_nm2idx['jsn']
# Collect facts and events
facts = []
evs = []
for ev_rec in event_records:
# Fill in the ID if it hasn't been set
if event_sequence_id is None:
event_sequence_id = ev_rec[id_idx]
# Get the event interval in order to distinguish between facts
# and events
lo = ev_rec[lo_idx]
hi = ev_rec[hi_idx]
# Missing times indicate a fact
if lo is None and hi is None:
fact = ((ev_rec[cat_idx], ev_rec[typ_idx]), ev_rec[val_idx])
facts.append(fact)
# Otherwise this record is an event
else:
ev = esal.Event(
esal.Interval(ev_rec[lo_idx], ev_rec[hi_idx]),
(ev_rec[cat_idx], ev_rec[typ_idx]),
(ev_rec[val_idx], ev_rec[jsn_idx]))
evs.append(ev)
return esal.EventSequence(evs, facts, event_sequence_id)
def test_backoff_zero_val(self):
evs = [
esal.Event(esal.Interval(2, 3), 'a', 1),
esal.Event(esal.Interval(5, 6), 'a', 1),
esal.Event(esal.Interval(9, 10), 'a', 1),
]
expected = [
(esal.Interval(0, 1), 0),
(esal.Interval(2, 3), 1),
(esal.Interval(5, 6), 1),
(esal.Interval(7, 8), 0),
(esal.Interval(9, 10), 1),
]
actual = list(events.periods(evs, 0, 11, backoff=1))
self.assertEqual(expected, actual)
expected.append((esal.Interval(11, 12), 0))
actual = list(events.periods(evs, 0, 12, backoff=1))
self.assertEqual(expected, actual)
def test_empty_span(self):
evs = [
esal.Event(esal.Interval(3, 5), 'a', 1),
esal.Event(esal.Interval(4, 6), 'a', 2),
esal.Event(esal.Interval(5, 5), 'a', 3),
esal.Event(esal.Interval(5, 7), 'a', 4),
]
expected = [
(esal.Interval(5, 5), 1),
(esal.Interval(5, 5), 2),
(esal.Interval(5, 5), 3),
(esal.Interval(5, 5), 4),
]
actual = list(events.periods(evs, 5, 5))
self.assertEqual(expected, actual)
def test_min_len(self):
evs = [
esal.Event(esal.Interval(1, 1), 'a', 1),
esal.Event(esal.Interval(4, 5), 'a', 1),
esal.Event(esal.Interval(7, 9), 'a', 1),
]
expected = [
(esal.Interval(1, 3), 1),
(esal.Interval(3, 4), 0),
(esal.Interval(4, 6), 1),
(esal.Interval(6, 7), 0),
(esal.Interval(7, 9), 1),
]
actual = list(events.periods(evs, 1, 9, min_len=2))
self.assertEqual(expected, actual)
def test_min_len_drop_empty_zero_val(self):
evs = [
esal.Event(esal.Interval(0, 2), 'a', 0),
esal.Event(esal.Interval(2, 2), 'a', 1),
esal.Event(esal.Interval(2, 4), 'a', 0),
esal.Event(esal.Interval(4, 4), 'a', 2),
esal.Event(esal.Interval(4, 9), 'a', 0),
]
expected = [
(esal.Interval(2, 4), 1),
(esal.Interval(4, 6), 2),
]
actual = list(events.periods(evs, 2, 6, min_len=2))
self.assertEqual(expected, actual)
def test_same_points(self):
evs = [
esal.Event(esal.Interval(1, 1), 'a', 1),
esal.Event(esal.Interval(1, 1), 'a', 1),
esal.Event(esal.Interval(1, 1), 'a', 2),
esal.Event(esal.Interval(1, 1), 'a', 2),
]
expected = [
(esal.Interval(1, 1), 1),
(esal.Interval(1, 1), 2),
]
actual = list(events.periods(evs, 1, 1))
self.assertEqual(expected, actual)
def test_merge(self):
evs = [
esal.Event(esal.Interval(1, 4), 'a', 1),
esal.Event(esal.Interval(4, 8), 'a', 1),
esal.Event(esal.Interval(6, 9), 'a', 2),
]
expected = [
(esal.Interval(0, 1), 0),
(esal.Interval(1, 6), 1),
(esal.Interval(6, 9), 2),
]
actual = list(events.periods(evs, 0, 9))
self.assertEqual(expected, actual)
def test_overlapping_intervals(self):
evs = [
esal.Event(esal.Interval(1, 3), 'a', 1),
esal.Event(esal.Interval(2, 4), 'a', 2),
esal.Event(esal.Interval(3, 5), 'a', 1),
esal.Event(esal.Interval(4, 6), 'a', 0),
esal.Event(esal.Interval(5, 7), 'a', 2),
esal.Event(esal.Interval(6, 8), 'a', 1),
]
expected = [
(esal.Interval(0, 1), 0),
(esal.Interval(1, 2), 1),
(esal.Interval(2, 3), 2),
(esal.Interval(3, 5), 1),
(esal.Interval(5, 6), 2),
(esal.Interval(6, 8), 1),
(esal.Interval(8, 9), 0),
]
actual = list(events.periods(evs, 0, 9))
self.assertEqual(expected, actual)
def periods(
events,
span_lo=None,
span_hi=None,
value=None,
zero_values=(0, None),
min_len=0,
backoff=0,
output_zero=0,
):
"""
Yield disjoint intervals corresponding to different values of the
given events.
Converts a sequence of events that approximately represent a signal
into a guess at the underlying piecewise constant signal (a sequence
of intervals that partitions a span of time, where each interval has
a value). Assumes the given events are sorted by their start times.
The conversion gives each interval a minimum length, unions
intervals with the same value and then puts them in sequence by
truncating an interval at the start of the next interval with a
different, nonzero value (with optional back-off). Finally, fills
in gaps with zero values. This is intended to be useful for
constructing event "eras" where the values of an event are mutually
exclusive (e.g. different dosages of a medication).
For example, in the following, the top collection of intervals would
be converted into the bottom sequence of intervals given min_len=6
and backoff=2.
--------------------------------------------------
222 22
11111 111 11111 11 11111
00000 00000 000000
--------------------------------------------------
00 111111 1111111 22222222222 000000 111111111 000
--------------------------------------------------
events:
Iterable of events.
span_lo:
Start (if any) of span to which events are clipped.
span_hi:
End (if any) of span to which events are clipped.
value:
Function to extract values from events: value(event) -> object.
Default uses `esal.Event.value`.
zero_values:
Set of values to treat as zero (non-signal) and ignore.
min_len:
Minimum length of each interval (prior to any truncation).
backoff:
Size of gap between intervals. A larger gap increases the
chances that an underlying transition from one value to the next
happened in the gap.
[TODO technically also need a starting lag / offset]
output_zero:
Value to use when filling in between nonzero values.
"""
prds = []
# Lengthen and clip nonzero periods
for ev in events:
# Ensure a minimum length before clipping
lo = ev.when.lo
hi = max(ev.when.hi, lo + min_len)
val = value(ev) if value is not None else ev.value
# Discard any events that are "non-events" (have zero value) or
# that are outside the allowed span
if (val in zero_values or
(span_lo is not None and hi < span_lo) or
(span_hi is not None and lo > span_hi)):
continue
# Clip to allowed span
if span_hi is not None:
hi = min(hi, span_hi)
if span_lo is not None:
lo = max(lo, span_lo)
prds.append((lo, hi, val))
# Merge and sequentialize periods
mrg_idx = 0
prd_idx = 1
while prd_idx < len(prds):
lo1, hi1, val1 = prds[mrg_idx]
lo2, hi2, val2 = prds[prd_idx]
# Merge periods with the same value
if hi1 >= lo2 and val1 == val2:
prds[mrg_idx] = (lo1, hi2, val1)
del prds[prd_idx]
else:
# Put periods in sequence by removing overlaps
if hi1 > lo2:
prds[mrg_idx] = (lo1, lo2, val1)
mrg_idx += 1
prd_idx += 1
# Yield periods with intervening zero periods as needed. Separate
# periods by backing off from the following nonzero event (if there
# is one).
zero_lo = span_lo
for (idx, (lo, hi, val)) in enumerate(prds):
# Yield a preceding zero period if it would be non-empty after
# backing off from the current event
zero_hi = lo - backoff
if zero_lo < zero_hi:
yield (esal.Interval(zero_lo, zero_hi), output_zero)
# Back off from the following nonzero event if there is one
hi_bk = (max(min(hi, prds[idx + 1][0] - backoff), lo)
if idx + 1 < len(prds)
else hi)
yield (esal.Interval(lo, hi_bk), val)
# Increment. Delay the zero period by the backoff amount.
zero_lo = hi_bk + backoff
if zero_lo < span_hi:
yield (esal.Interval(zero_lo, span_hi), output_zero)
def mk_feature_vectors(
events_csv_filename,
examples_csv_filename,
features_csv_filename,
events_csv_format=events.csv_format,
examples_csv_format=examples.csv_format,
features_csv_format=csv_format,
events_header=events.header(),
examples_header=examples.header(),
features_header=header(),
events_header_detector=True,
examples_header_detector=True,
features_header_detector=True,
include_event_record=None,
transform_event_record=None,
include_example_record=None,
always_feature_keys=(),
feature_function_namespaces=None,
feature_function_modules=None,
):
"""
Make and yield feature vectors.
Yields (example-label, example-weight, feature-vector) triples.
"""
# Unpack events header
ev_hdr_nm2idx = {f[0]: i for i, f in enumerate(events_header)}
ev_id_idx = ev_hdr_nm2idx['id']
# Unpack examples header
ex_hdr_nm2idx = {f[0]: i for i, f in enumerate(examples_header)}
ex_id_idx = ex_hdr_nm2idx['id']
ex_lo_idx = ex_hdr_nm2idx['lo']
ex_hi_idx = ex_hdr_nm2idx['hi']
# Load example definitions
exs = records.read_csv(examples_csv_filename,
examples_csv_format,
examples_header,
examples_header_detector,
include_record=include_example_record)
# Collect examples by ID
id2ex = collections.defaultdict(list)
for ex in exs:
id2ex[ex[ex_id_idx]].append(ex)
# Load feature definitions
_, _, feat_key2idsfuncs = load(
features_csv_filename,
features_csv_format,
features_header,
features_header_detector,
feature_function_namespaces,
feature_function_modules,
)
# Create a feature vector for each example definition. Only
# construct event sequences for IDs that have examples.
for ev_seq in events.read_sequences(
records.read_csv(
events_csv_filename,
events_csv_format,
events_header,
header_detector=events_header_detector,
parser=False,
),
header=events_header,
parse_id=events_header[ev_id_idx][1],
include_ids=id2ex,
parse_record=records.mk_parser(events_header),
include_record=include_event_record,
transform_record=transform_event_record,
):
# Skip any IDs without examples
for ex in id2ex.get(ev_seq.id, ()):
# Create a subsequence that includes all the events that
# overlap the example period
itvl = esal.Interval(ex[ex_lo_idx], ex[ex_hi_idx])
subseq = ev_seq.subsequence(
ev_seq.events_overlapping(itvl.lo, itvl.hi, itvl.is_lo_open,
itvl.is_hi_open))
# Create feature vector
fv = vector(feat_key2idsfuncs, ex, subseq, always_feature_keys)
# Yield example and its feature fector
yield ex, fv
