Description
eligibleArea is their difference; samplingFraction = sampledArea/eligibleArea; expansionWeight is its reciprocal.
Ecological sampling summaries distinguish effort, weighted support, taxon counts and relative composition. A denominator-specific fraction or single-species contribution need not describe abundance, completeness or a whole-community index.
eligibleArea is their difference; samplingFraction = sampledArea/eligibleArea; expansionWeight is its reciprocal.
When to use this tool
Use Plot Sampling Fraction Weight when checking a supplied ecological effort, support or count convention.
How to use the tool and how it works
- Enter sampledArea, targetArea, excludedArea. Use the units and conventions below.
- Run the tool. Correct any format, range, or cross-field input error before interpreting the output.
- Read eligibleArea, samplingFraction, expansionWeight. Use the output convention below.
Require positive sampledArea, nonnegative excludedArea and targetArea > excludedArea, with sampledArea <= targetArea-excludedArea. eligibleArea is their difference; samplingFraction = sampledArea/eligibleArea; expansionWeight is its reciprocal.1
| Input field | Meaning and units | Accepted input |
|---|---|---|
| sampledArea | Sampled Area | Required. Finite number; strictly above 0. |
| targetArea | Target Area | Required. Finite number. |
| excludedArea | Excluded Area | Required. Finite number; minimum 0. |
| Output field | Interpretation | Returned shape |
|---|---|---|
| eligibleArea | Eligible Area | Required. Finite number. |
| samplingFraction | Sampling Fraction | Required. Finite number. |
| expansionWeight | Expansion Weight | Required. Finite number. |
{
"input": {
"sampledArea": 10,
"targetArea": 100,
"excludedArea": 20
},
"output": {
"eligibleArea": 80,
"samplingFraction": 0.125,
"expansionWeight": 8
}
}Limitations and assumptions
- The weight assumes a suitable equal-area sampling interpretation. No inclusion probability, spatial representativeness or survey design 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
Use an appropriate sampling, detection and community-analysis method for inference beyond these local summaries.
References
Similar or alternative tools
- Seed Rain Trap Edge Adjustment
weightedSeeds = interiorSeeds+edgeSeeds*edgeWeight; density = weightedSeeds/trapArea.
- Seedrain Density Trap Area Time Factor
areaDays = traps*trapArea*exposedDays*operationalFraction; densityPerAreaDay = seeds/areaDays.