Description
Check a supplied historical code against half-open era intervals.
Historical and archival records distinguish source labels, local grid conventions, edition numbers and validity periods. A parsed token or geometric area term cannot establish provenance, historical identity or land rights. Date endpoints, text-counting units and numbering origins must match the original record.
Check a supplied historical code against half-open era intervals.
When to use this tool
Use Historical State Code Era Flag when checking the stated archival record, grid, edition or validity-period convention.
How to use the tool and how it works
- Enter code, codes, starts, ends, coordinate. Follow any array-alignment requirements below. Use the units and conventions below.
- Run the tool. Correct any format, range, or cross-field input error before interpreting the output.
- Read knownCode, validAtCoordinate. Inspect knownCode, validAtCoordinate before interpreting the associated values.
Check a supplied historical code against half-open era intervals. Require aligned arrays and ordered starts/ends; knownCode tests any label match, validAtCoordinate requires a matched interval with start <= coordinate < end.1
| Input field | Meaning and units | Accepted input |
|---|---|---|
| code | Code | Required. Text; maximum UTF-16 length 8192. |
| codes | Codes | Required. Array of text; maximum UTF-16 length 8192; maximum items 256. |
| starts | Validity starts, included. | Required. Array of finite number; maximum items 256. |
| ends | Validity ends, excluded; validAtCoordinate also requires a literal code match. | Required. Array of finite number; maximum items 256. |
| coordinate | Coordinate | Required. Finite number. |
| Output field | Interpretation | Returned shape |
|---|---|---|
| knownCode | Known Code | Required. Boolean. |
| validAtCoordinate | Valid At Coordinate | Required. Boolean. |
{
"input": {
"code": "XY",
"codes": [
"XY"
],
"starts": [
1800
],
"ends": [
1900
],
"coordinate": 1850
},
"output": {
"knownCode": true,
"validAtCoordinate": true
}
}Limitations and assumptions
- Zero-width intervals contain no coordinate; no state history, source authority or actual code applicability is independently verified.
- 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
Consult the original archive, survey and applicable authority for historical interpretation, provenance or actual property rights.
References
Similar or alternative tools
- Census Variable Era Gap
Return exact census-edition difference and definition-label change.
- Public Census Field Width Tool
Inspect one supplied public census field against an explicit character/code-unit width budget.