Interval Endpoint Event Table
Build grouped endpoint event tables with starts, ends and empty intervals separately; simultaneous events are not silently ordered.
Description
Build grouped endpoint event tables with starts, ends and empty intervals separately; simultaneous events are not silently ordered.
Endpoint events show where intervals begin, end or collapse to a point. They are useful when preparing a sweep over a collection of spans.
When to use this tool
Build grouped endpoint event tables with starts, ends and empty intervals separately; simultaneous events are not silently ordered.
- Prepare the supplied intervals 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 intervals. 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.events. Interpret false, null and empty lists using the distinctions below; they can be valid outputs.
Sort all distinct endpoints and report source indexes starting or ending there for positive-length intervals. Put zero-length intervals in a separate emptyIndexes list at their shared endpoint.1
| Input field | Meaning and representation | Accepted input |
|---|---|---|
| intervals | intervals. | Numeric rows; at most 128 rows and 128 values per row |
| Output field | Interpretation |
|---|---|
| result | Object containing the named outputs below. |
| result.events | The events list in the ordering and representation described above. |
{
"input": {
"intervals": [
[
0,
1
],
[
1,
2
]
]
},
"output": {
"result": {
"events": [
{
"endpoint": 0,
"startingIndexes": [
0
],
"endingIndexes": [],
"emptyIndexes": []
},
{
"endpoint": 1,
"startingIndexes": [
1
],
"endingIndexes": [
0
],
"emptyIndexes": []
},
{
"endpoint": 2,
"startingIndexes": [],
"endingIndexes": [
1
],
"emptyIndexes": []
}
]
}
}
}Limitations and assumptions
- The table retains input identities but does not calculate coverage after each event. Degenerate intervals do not enter the starting/ending lists.
- Interval-array rows contain exactly two finite endpoints in start/end order, with at most 128 intervals per collection. Individual operations state when positive length, integer endpoints or explicit inclusion flags are required.
- 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
Retain the endpoint convention with every result. Continuous length, integer point counts and open/closed membership differ; merge returned cells separately when a canonical minimal interval collection is required.
References
Similar or alternative tools
- Interval Shared Endpoint Classifier
Identify exact shared endpoint values independently of whether interval interiors overlap.
- Interval Affine Transform
Affine-transform interval endpoints, reorder the image bounds and retain negative-scale orientation reversal.