SciDB

Database operations layer for SciStack. Provides abstractions for defining typed variables, configuring the database, and saving/loading data by metadata.

Named Filters (value-based, reusable)

Filter objects are first-class values — assign them to a variable and reuse them in any where= clause, or compose them with & / | / ~:

# Define once (this IS a ColumnFilter — no special wrapper needed)
clean_gr = GAITRiteLoadedCycle["StepLengths_GR"] != 0

# Use anywhere
for_each(mean_change_from_reference,
         inputs={"baseline": Fixed(GAITRiteLoadedCycle["StepLengths_GR"], session="BL"),
                 "value":    GAITRiteLoadedCycle["StepLengths_GR"]},
         outputs=[DeltaStepLength],
         where=clean_gr & (UAStartFoot() == "A"))

# Compose named filters
clean_and_unilateral = clean_gr & (UAStartFoot() == "U")
for_each(..., where=clean_and_unilateral)

MATLAB equivalent:

clean_gr = GAITRiteLoadedCycle("StepLengths_GR") ~= 0;
scidb.for_each(@meanChangeFromReference, ..., where=clean_gr & (UAStartFoot() == "A"));

Permanent Schema-Level Exclusions

For data that should be excluded from every analysis (e.g., a failed recording session), use the exclusion registry instead of per-call filters.

# Mark a specific trial as excluded (persisted in the database)
scidb.exclude_schema(subject=1, trial=2,
                     reason="equipment malfunction during recording")

# Exclude an entire subject (trial omitted = wildcard)
scidb.exclude_schema(subject=3, reason="participant withdrew")

# Inspect currently-excluded combinations
exclusions_df = scidb.list_exclusions()

# Re-include (logged; the original exclusion row is preserved)
scidb.include_schema(subject=1, trial=2,
                     reason="re-reviewed video, recording was valid")

MATLAB equivalent:

scidb.exclude_schema("equipment malfunction", 'subject', 1, 'trial', 2)
scidb.include_schema("re-reviewed, recording was valid", 'subject', 1, 'trial', 2)
tbl = scidb.list_exclusions()

Exclusions are applied automatically by for_each before the iteration loop. The full exclusion table is hashed and stored in version_keys (__schema_overrides_hash) so that adding or removing an exclusion invalidates cached results.

from scidb import configure_database, BaseVariable
import numpy as np

db = configure_database("experiment.duckdb", ["subject", "session"])

class RawSignal(BaseVariable):
    schema_version = 1

RawSignal.save(np.array([1, 2, 3]), subject=1, session="A")
(raw,) = RawSignal.load(subject=1, session="A")  # generator; unpack for single result
all_versions = list(RawSignal.load(subject=1, session="A", version="all"))

Logging

Every scidb operation logs through the shared scistacklog facade. configure_database() points the file sink at scidb.log next to the database file and writes a run-context header (package versions, Python version, pid), so each log file is self-describing.

Two sinks with independent levels, both defaulting to INFO:

• console (stderr): the pipeline narrative — for_each banner, periodic progress, run summary with failure reasons, [timing] summaries.
• file (scidb.log): the same narrative, with date + millisecond timestamps and the originating layer ([scidb], [scifor], [matlab], …) on every line; one record per line.

For debugging, raise a sink to DEBUG to capture the full execution trace (named internal steps with durations, per-iteration [run]/[skip] lines, per-phase [timing] tables, column/dtype dumps):

from scidb import Log

Log.set_level("DEBUG", sink="file")   # full detail in scidb.log only
Log.set_level("DEBUG")                # both sinks

or set the SCIDB_LOG_LEVEL environment variable, or pass -v to the scidb CLI.