Description
Sum each array and return fraction = supportedVolume/totalVolume when totalVolume > 0, otherwise fraction = 0 and defined = false.
Environmental monitoring coverage depends on what counts in the denominator. Time, effort, area, sampled volume and exposure weights describe different support measures; excluding missing or ineligible portions changes the question answered by a fraction.
Sum each array and return fraction = supportedVolume/totalVolume when totalVolume > 0, otherwise fraction = 0 and defined = false.
When to use this tool
Use Sample Support Volume Fraction when checking a monitoring or sampling share with an explicit inclusion and overlap convention.
How to use the tool and how it works
- Enter supportedVolumes, totalVolumes. 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 supportedVolume, totalVolume, fraction, defined. Inspect defined before interpreting the associated values.
Require equally long supportedVolumes and totalVolumes with 0 <= supportedVolumes[i] <= totalVolumes[i]. Sum each array and return fraction = supportedVolume/totalVolume when totalVolume > 0, otherwise fraction = 0 and defined = false. Use one volume unit across records.1
| Input field | Meaning and units | Accepted input |
|---|---|---|
| supportedVolumes | Supported Volumes | Required. Array of finite number; maximum items 256. |
| totalVolumes | Total Volumes | Required. Array of finite number; maximum items 256. |
| Output field | Interpretation | Returned shape |
|---|---|---|
| supportedVolume | Supported Volume | Required. Finite number. |
| totalVolume | Total Volume | Required. Finite number. |
| fraction | Dimensionless ratio under the stated denominator convention; not multiplied by 100. | Required. Finite number. |
| defined | Whether the denominator is positive and the returned ratio is defined; inspect this before using a zero placeholder. | Required. Boolean. |
{
"input": {
"supportedVolumes": [
1,
2
],
"totalVolumes": [
2,
3
]
},
"output": {
"supportedVolume": 3,
"totalVolume": 5,
"fraction": 0.6,
"defined": true
}
}Limitations and assumptions
- This is a volume-weighted support share, not an unweighted mean of record fractions. Empty and all-zero totals are undefined, and overlapping sample volumes are not deduplicated.
- 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
Review source intervals and sampling design, and compute overlaps from actual records when an aggregate deduction cannot be justified.
References
Similar or alternative tools
- Person Time Risk Support Share
Sum nonnegative personTime for atRisk entries into atRiskTime, and for entries with both atRisk and observed into observedRiskTime; the arrays must have equal lengths.
- Transect Segment Effort Share
Return share = segmentEffort/totalEffort.