Relative Frequency Calculator
Actual Species relative frequency divided by SUM frequencies, not absolute plot occurrence percentage, matching plot population/units, not community causal importance.
Description
Relative frequency compares a species' frequency with the sum of all species frequencies on the same sampling basis.
Relative frequency compares a species' frequency with the sum of all species frequencies on the same sampling basis.1
This tool calculates that percentage rather than an absolute plot-occurrence percentage.
When to use Relative Frequency Calculator
Use this tool to calculate that percentage rather than an absolute plot-occurrence percentage.
How to use Relative Frequency Calculator and how it works
- Prepare actualSpeciesPlotFrequencySum, actualAllSpeciesPlotFrequencySum, with the units, conventions and assumptions below.
- Enter the required fields and run Relative Frequency Calculator.
- Read result.value using the output definitions below.
- Correct any rejected inputs and rerun; interpret the result within the stated model and its assumptions.
| Input field | Meaning | Value type | Requirement |
|---|---|---|---|
| actualSpeciesPlotFrequencySum | Actual Species Plot Frequency Sum. Use the units and matching context stated in the calculation below. | number | Required; nonnegative; finite; other constraints below |
| actualAllSpeciesPlotFrequencySum | Actual All Species Plot Frequency Sum. Use the units and matching context stated in the calculation below. | number | Required; strictly positive; finite; other constraints below |
Require a nonnegative species amount and a positive corresponding total, with the species amount no greater than the total. Return 100*species/total as a percent. Relative frequency uses matching occurrence counts and relative dominance uses matching basal-area totals; the observation basis is supplied rather than checked by the tool.
percent=100*speciesAmount/totalAmount Apply the input ordering, units and branch conditions stated above.
| Output field | Meaning | Value type |
|---|---|---|
| result | Object containing the calculated or selected fields below. | object |
| result.value | Relative amount as percent, from zero to 100 inclusive. | number |
{
"input": {
"actualSpeciesPlotFrequencySum": 2,
"actualAllSpeciesPlotFrequencySum": 4
},
"output": {
"result": {
"value": 50
}
}
}Limitations and assumptions
The calculation uses the supplied observations and model inputs. It does not collect measurements, select a reference population or coefficient, or establish that the model applies to the actual case. The stated branch conditions and output units remain part of the result.
All fields require explicit values. Unexpected fields, wrong types, nonfinite numbers and sparse arrays are rejected. Alignment, bounds and supported-token rules are explained above; extremely large inputs or nonfinite results can also fail. Input errors differ from successful false comparisons, unavailable-domain flags and empty match lists.
Alternative or Complementary methods
Use Relative Dominance Calculator for a complementary operation: Relative dominance can express a species' basal area as a share of all-species basal area.
Use Stems Per Hectare Density Calculator for a complementary operation: A sampled stem-density estimate depends on independently qualified live stems and measured plot area.
References
-
Relative Frequency Calculator — tool.io
Similar or alternative tools
- Relative Dominance Calculator
Relative dominance can express a species' basal area as a share of all-species basal area.
- Stems Per Hectare Density Calculator
A sampled stem-density estimate depends on independently qualified live stems and measured plot area.