Description
Divide for activeFraction and subtract for inactiveLength.
Urban indicators compare counts or areas within a defined study boundary. Changing the denominator, the counted units, or whether a share is expressed as a fraction changes the meaning even when the arithmetic is correct.
Divide for activeFraction and subtract for inactiveLength.
When to use this tool
Use Frontage Active Length Fraction when you need a reproducible density or share using an explicitly chosen study boundary and denominator.
How to use the tool and how it works
- Enter activeLength, totalFrontage. Use the units and conventions below.
- Run the tool. Correct any format, range, or cross-field input error before interpreting the output.
- Read activeFraction, inactiveLength. Use the output convention below.
Require activeLength between zero and positive totalFrontage. Divide for activeFraction and subtract for inactiveLength.1
| Input field | Meaning and units | Accepted input |
|---|---|---|
| activeLength | Active Length | Required. Finite number; minimum 0. |
| totalFrontage | Total Frontage | Required. Finite number; strictly above 0. |
| Output field | Interpretation | Returned shape |
|---|---|---|
| activeFraction | Active Fraction | Required. Finite number. |
| inactiveLength | Inactive Length | Required. Finite number. |
{
"input": {
"activeLength": 60,
"totalFrontage": 80
},
"output": {
"activeFraction": 0.75,
"inactiveLength": 20
}
}Limitations and assumptions
- Active frontage is a caller-defined classification; actual use, design quality, and regulation are not assessed.
- 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
Document the data definitions and compare several planning indicators rather than treating one ratio as a design verdict.
References
Similar or alternative tools
- Facade Opening Solid Share
Return opening/facade, facade minus opening, and that solid remainder divided by facade.
- Block Intersection Density Input
Divide nonnegative safe-integer intersectionCount by positive areaSquareKilometers.