Flag Change Frequency per Century Estimator
Change-event rate per100nominal calendar years within an independently fully observed half-open interval; events must be counted inside that interval. Not a forecast or uncertain historical completeness correction.
Description
Flag-change frequency requires a counted event total and a fully observed interval.
Flag-change frequency requires a counted event total and a fully observed interval.1
Scaling the count to a century summarizes that interval without forecasting the next change.
When to use Flag Change Frequency per Century Estimator
Use this tool when you need to reproduce the stated calculation from measured records or independently selected model inputs. Establish the flag dimensions, orientation, specification, palette, or visual annotations needed for this particular calculation.
How to use Flag Change Frequency per Century Estimator and understand its results
- Establish the flag dimensions, orientation, specification, palette, or visual annotations needed for this particular calculation.
- Enter observedChangeCount, fullyObservedIntervalStartYear, fullyObservedIntervalEndYearExclusive, following the field table and rules below, then run the tool.
- Read result. Use the output meanings below to interpret units, signs, flags, and any nested result fields.
- Correct reported input issues and run again. For a successful result, check the stated evidence coverage and assumptions before using it in your review.
| Input field | Meaning | Value type | Requirement |
|---|---|---|---|
| observedChangeCount | Observed change count | number | Required |
| fullyObservedIntervalStartYear | Fully observed interval start year | number | Required |
| fullyObservedIntervalEndYearExclusive | Fully observed interval end year exclusive | number | Required |
Enter an integer count from zero to one million, a start CE year from one to 9999, and an exclusive end year greater than start and at most 10000. Exposure is end minus start; events must already have been counted within that half-open interval.
frequency=100count/(endExclusive−start) Symbols follow the input and output meanings and the calculation rules above.
| Output field | Meaning | Value type |
|---|---|---|
| result | Calculated observation or reference | object |
| result.changesPerCentury | Changes Per Century | number |
| result.nominalExposureYears | Nominal Exposure Years | number |
{
"input": {
"observedChangeCount": 3,
"fullyObservedIntervalStartYear": 1900,
"fullyObservedIntervalEndYearExclusive": 2000
},
"output": {
"result": {
"changesPerCentury": 3,
"nominalExposureYears": 100
}
}
}Limitations and assumptions
The calculation uses supplied geometry, observations, or annotations. It does not establish an official construction specification, national identity, or universal design quality.
Missing required fields, unknown fields, wrong types, and violated calculation rules are input issues. Numeric values must be finite; nonfinite results are rejected. Extremely large composite outputs are rejected.
Alternative or Complementary methods
For a related review, use Historical Adoption Year Sorter: A chronological flag-design list needs verified adoption years and stable treatment of ties. This sorter keeps the original order when multiple designs share a year. For a complementary step, use Historical Eruption Frequency Per Century Calculator: Historical eruption frequency needs both counted events and an observation period judged sufficiently complete. Pooling only qualified windows prevents incomplete catalog coverage from silently becoming a recurrence estimate.
References
Similar or alternative tools
- Historical Adoption Year Sorter
A chronological flag-design list needs verified adoption years and stable treatment of ties. This sorter keeps the original order when multiple designs share a year.
- Historical Eruption Frequency Per Century Calculator
Historical eruption frequency needs both counted events and an observation period judged sufficiently complete. Pooling only qualified windows prevents incomplete catalog coverage from silently becoming a recurrence estimate.