Time and result quality

These meanings apply across analysis features. dataset.domain selects the requested time range, signals[].valid_for controls how long a previous value remains usable, and execution.partial_policy or the calculation-level field controls partial results. Use this page before configuring signals, rules and calculations.

Requested and observed ranges

dataset.domain is the range you ask to analyze. The observed range is where data was actually recorded. A request for [0,12) with a log ending at 8 s cannot establish results for the final four seconds.

[0,1) means from 0 s inclusive to 1 s exclusive: a duration of one second. The next interval [1,2) therefore does not count the boundary twice.

A button transition exactly at the requested endpoint may produce a point event only when there is an actual observation at that time and the rule's trigger conditions hold. The request ending does not itself produce an event. A point event has a timestamp and no end (end_ns is null); it is not a one-nanosecond activity. Continuous durations use half-open intervals.

Internally, time uses integer nanoseconds: one second is 1,000,000,000 ns. Conversion records rounding when input is finer than nanoseconds. Converting to integers cannot recover precision already lost in a floating-point timestamp.

Signal validity periods

Suppose current is 10 A at 0 s and valid_for="2s". Without an update, it may remain 10 A before 2 s, provided the source actually records that range; at 2 s it expires. If observations end at 1 s, validity does not create data for 1–2 s. An explicitly invalid update at 1 s invalidates the value immediately, rather than preserving the old value. An empty CSV cell is also an invalid update.

Keep original field names, expression aliases and semantic identifiers separate. Bind BMS_BatCurr to current, then write current > 5. Optional semantic_id="battery.current" is a meaning label; battery.current > 5 is rejected as an expression. Ordinary analyses do not require a semantic catalog.

Condition expressions

current > 5 and mode == 1 means current exceeds 5 A and mode equals 1. Define both names under signals; an unbound input column cannot be referenced directly.

The expression guide lists all supported operators and the functions available in each configuration version: unary signs, four arithmetic operations, six comparisons, and/or/not, chained comparisons, parentheses, constants, enums, and type/unit restrictions. This page explains how those values behave over time.

UNKNOWN is not False

When inputs are invalid, the condition's truth is unknown (UNKNOWN). False and UNKNOWN is known False; True or UNKNOWN is known True; True and UNKNOWN remains unknown. Quality reasons are retained.

If a device is known to run at 1 s but its status is missing at 2 s, that is an interruption (interrupted), not a known stop (closed). A rising edge requires known False followed by known True. Unknown followed by True is not normally such an edge. rising_edge and start_only can use emit_initial to emit an event when the first known state of the analysis is True; it does not create an initial falling edge. Initial unknown followed by the first known True qualifies. Once False has already been observed, a later unknown-to-True change is neither an initial state nor evidence of a known False-to-True edge.

Activities, point events and context segments

Rule/object	Behavior
`condition_duration`	True from 1 s with `minimum_duration="3s"` is confirmed at 4 s. Energy may include or exclude the waiting three seconds; see selection_origin.
`rising_edge` / `falling_edge`	Record the instant of a known False-to-True or True-to-False change. A transition at 2 s records that point, not how long the state persists.
`start_only`	After a button press, take five seconds of data and ignore presses during that interval. A button still held after five seconds does not automatically retrigger.
`Event`	An activity's start, confirmation, end and reason, or a point trigger time.
`Segment`	The range selected around events, such as one extra second before and after an activity. `parent_event_ids` identifies related events.

If a device runs during 0–1 s, stops during 1–2 s, and runs during 2–3 s, a rule with no confirmation delay records two activities.

To inspect three seconds after each stop, set window exit_delay="3s". Because the second activity starts during that wait, both can occupy one segment covering 0–6 s. The event table still contains two activities. The one-second stop is included in the segment but is not converted into activity time.

Statistics

Sample means and time means use different weights. Ordinary integration and per-message accumulation also use different time bases. See statistics and integrals for selection, formulas and coverage thresholds.

Zero, null and partial results

Situation	Result
Complete observations establish that the condition is always False	Conditional integral and selected duration are 0. `min/max/mean` are null because no samples were selected.
1000 W with a True condition for one second, followed by one second of unknown condition	Under `report`, the verifiable result is 1000 J with status `partial` and a reason. The public summary has no numeric coverage ratio. Under `strict`, the value is null.
Entirely unknown condition, no observations, or a zero-length request	Do not report a normal zero; retain the specific reason.
Valid positive and negative contributions cancel to zero	A valid numeric zero, distinct from missing data.

partial_policy="report" keeps the known part; "strict" withholds the number when required data is incomplete. minimum_coverage specifies the minimum coverage required by the user; it cannot fill missing data. See execution settings for numeric comparisons. Read value, unit, status, reason and quality together.

Ordinary scalar integral, duration, min_time, max_time, time_weighted_mean, sample_minimum, sample_maximum, sample_mean, and v4 sample counts, variance, standard deviation, RMS and sample quantiles return coverage_status when minimum_coverage > 0. sufficient means observation, valid-value and known-condition coverage all meet the threshold; indeterminate means insufficient or undetermined. This is not a numeric coverage ratio and does not turn sample statistics into time-weighted statistics. select details and per-message accumulation are not in this scalar group. Public summaries do not expose numeric requested_coverage, value_coverage or condition_coverage. See the implementation summary reference (Chinese).

Time integration versus per-message accumulation

Actual-time integration uses elapsed time. legacy_sum adds each matching message's expression result. If the expression already contains power * period, 4000 W × 0.1 s is 400 J and two messages at the same timestamp still contribute 800 J; do not multiply by dt again. Messages with missing values are skipped with a reason, without borrowing the previous value. See per-message calculations.