Description
Return start, end, or interior based on its numeric position.
A line's positions have an order, and endpoint or insertion rules depend on indexes in that order. Sequence length and index validity do not establish a geographic route, nondegenerate segments, or a valid complete geometry.
Return start, end, or interior based on its numeric position.
When to use this tool
Use Linestring Vertex Index Endpoint Role when you need a local line-position or sequence-index operation.
How to use the tool and how it works
- Enter count, index. Use the units and conventions below.
- Run the tool. Correct any format, range, or cross-field input error before interpreting the output.
- Read role. Use the output convention below.
Require count at least two and index from zero through count-1. Return start, end, or interior based on its numeric position.1
| Input field | Meaning and units | Accepted input |
|---|---|---|
| count | Count under the documented selection and duplicate convention. | Required. Safe integer; minimum 2. |
| index | Position under the documented indexing convention; inspect any absence sentinel. | Required. Safe integer; minimum 0. |
| Output field | Interpretation | Returned shape |
|---|---|---|
| role | Role | Required. Text; maximum UTF-16 length 8192. |
{
"input": {
"count": 5,
"index": 2
},
"output": {
"role": "interior"
}
}Limitations and assumptions
- The coordinates are not supplied; role does not establish a valid LineString, endpoint identity, distinctness, geographic location, or path length.
- Inputs must satisfy both the field types and the cross-field conditions above. Invalid input causes an error; a successful false flag or documented placeholder is a different result.
- Numeric calculations use binary floating point unless exact decimal-integer arithmetic is explicitly stated. No hidden measurement tolerance or decimal rounding is added; nonfinite or out-of-contract results are rejected. Numeric signed-zero results are exported as zero.
Alternative or Complementary methods
Validate the entire coordinate sequence and intended geometry after edits. Use a routing or geodesic method for questions about actual travel paths or physical distances.
References
Similar or alternative tools
- Linestring Coordinate One Insertion Count
Return count+1 and endpoint for insertion at zero or count.
- Linestring Two Point Degeneracy Flag
Mark degenerate when every ordinate is exactly equal.