Threshold Upcrossing Indexes
Find up crossings from strictly below to the threshold-or-beyond; equality plateaus do not repeatedly trigger.
Description
Find up crossings from strictly below to the threshold-or-beyond; equality plateaus do not repeatedly trigger.
A sampled upcrossing is a transition from strictly below a threshold to at or above it. Its index identifies the first qualifying arrival sample.
When to use this tool
Find up crossings from strictly below to the threshold-or-beyond; equality plateaus do not repeatedly trigger.
- Prepare the supplied values, threshold fields for this operation.
- Compare the complete example with the representation used by your own input before carrying the result into another step.
How to use the tool and how it works
- Enter values, threshold. Use the exact text syntax, units and index conventions explained below.
- Run the tool. If input validation fails, correct the supplied fields before interpreting any result.
- Read result.crossingIndexes. Interpret false, null and empty lists using the distinctions below; they can be valid outputs.
Scan adjacent values and return index j exactly when value[j-1] is below threshold and value[j] is at or above it.1
| Input field | Meaning and representation | Accepted input |
|---|---|---|
| values | values. | List of finite numbers; bounded by the operation |
| threshold | threshold. | Finite number |
| Output field | Interpretation |
|---|---|
| result | Object containing the named outputs below. |
| result.crossingIndexes | The crossing indexes list in the ordering and representation described above. |
{
"input": {
"values": [
0,
1,
2,
1,
0
],
"threshold": 1
},
"output": {
"result": {
"crossingIndexes": [
1
]
}
}
}Limitations and assumptions
- Leaving a sample already equal to the threshold does not count. There is no interpolation, hysteresis or noise tolerance, and a first sample alone cannot form a crossing.
- Every declared top-level field is required and unexpected fields are rejected. Numeric inputs must be finite; ordinary text fields are bounded to 8,192 UTF-16 code units, with tighter operation-specific limits where stated.
- Ordinary string lists have at most 128 entries of at most 128 code units each; numeric lists and matrices have separate bounded size checks. Nonfinite results and excessively large serialized outputs are rejected.
- Indexes are zero-based and spans have an exclusive end unless explicitly stated otherwise. A valid false, null or empty-list result is distinct from malformed input.
Alternative or Complementary methods
Choose a sampling model before combining results. Earlier-sample hold, linear interpolation and index-only differences answer different questions; event cooldown, debounce and rolling limits also use different acceptance rules.
References
Similar or alternative tools
- Threshold Downcrossing Indexes
Find down crossings from strictly above to the threshold-or-beyond; equality plateaus do not repeatedly trigger.
- Consecutive Threshold Streaks
Tabulate sampled consecutive threshold streaks with explicit at-or-above versus strictly-below convention; no between-sample duration inference.