Description
Apply explicit independent area credit factors; no local regulation is selected.
Planning indicators combine supplied counts, time intervals, distances, and area definitions. The denominator, geometric envelope, and category boundaries affect a reported density or share. A scenario calculation follows those assumptions while the governing rules and actual site conditions require separate verification.
Apply explicit independent area credit factors; no local regulation is selected.
When to use this tool
Use Permeable Surface Credit Explicit Factor when you need an explicit scenario indicator from supplied site dimensions, service records, or policy assumptions.
How to use the tool and how it works
- Enter areas, creditFactors, lotArea. Keep parallel arrays aligned. Use the units and conventions below.
- Run the tool. Correct any format, range, or cross-field input error before interpreting the output.
- Read creditedArea, creditedFraction. Use the output convention below.
Require aligned nonnegative areas and creditFactors within zero through one, and positive lotArea. Return creditedArea=sum(area*creditFactor) and creditedFraction=creditedArea/lotArea.1
| Input field | Meaning and units | Accepted input |
|---|---|---|
| areas | Areas | Required. Array of Finite number.; maximum items 256. |
| creditFactors | Credit Factors | Required. Array of Finite number.; maximum items 256. |
| lotArea | Lot Area | Required. Finite number; strictly above 0. |
| Output field | Interpretation | Returned shape |
|---|---|---|
| creditedArea | Credited Area | Required. Finite number. |
| creditedFraction | Supplied credited area divided by lotArea; not constrained to one. | Required. Finite number. |
{
"input": {
"areas": [
100,
50
],
"creditFactors": [
1,
0.5
],
"lotArea": 500
},
"output": {
"creditedArea": 125,
"creditedFraction": 0.25
}
}Limitations and assumptions
- Areas are not bounded by lotArea and overlapping inputs can make creditedFraction exceed one. Credits are supplied policy factors, not measured infiltration, runoff performance, or a verified regulatory credit.
- The field tables state structural bounds; the mechanics also specify cross-field constraints. Malformed inputs and unsupported domains cause errors. A successful false flag, empty branch value, or zero placeholder has the meaning stated above and is distinct from an input error.
- 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. Signed zero is exported as zero.
Alternative or Complementary methods
Check measured site data and the applicable authoritative definitions before using a scenario in a planning decision. Geographic analysis, transport modeling, or a complete design review may be needed beyond the stated term.
References
Similar or alternative tools
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