Description
Return the Tversky ratio for nonzero weighted denominator, otherwise emptyValue with defined false.
A similarity term depends on the comparison universe, missing-value policy, treatment of repeated features, and normalization. A score can also have a caller-selected value when its mathematical denominator vanishes. Those conventions matter before interpreting a threshold or comparing methods.
Return the Tversky ratio for nonzero weighted denominator, otherwise emptyValue with defined false.
When to use this tool
Use Tversky Empty Reference Policy when you need this particular comparison term, normalization, domain condition, or empty-result policy in a larger matching workflow.
How to use the tool and how it works
- Enter intersection, leftOnly, rightOnly, alpha, beta, emptyValue. Use the units and conventions below.
- Run the tool. Correct any format, range, or cross-field input error before interpreting the output.
- Read defined, score. Inspect defined before interpreting the associated values.
Return the Tversky ratio for nonzero weighted denominator, otherwise emptyValue with defined false. Require nonnegative integer counts, nonnegative penalties, and fallback within zero through one.1
| Input field | Meaning and units | Accepted input |
|---|---|---|
| intersection | Intersection | Required. Safe integer; minimum 0. |
| leftOnly | Left Only | Required. Safe integer; minimum 0. |
| rightOnly | Right Only | Required. Safe integer; minimum 0. |
| alpha | Alpha | Required. Finite number. |
| beta | Beta | Required. Finite number. |
| emptyValue | Empty Value | Required. Finite number; minimum 0; maximum 1. |
| Output field | Interpretation | Returned shape |
|---|---|---|
| defined | Whether the weighted denominator is nonzero, even for nonempty supports. | Required. Boolean. |
| score | Score | Required. Finite number. |
{
"input": {
"intersection": 0,
"leftOnly": 0,
"rightOnly": 0,
"alpha": 1,
"beta": 1,
"emptyValue": 1
},
"output": {
"defined": false,
"score": 1
}
}Limitations and assumptions
- A zero denominator can occur with nonempty disjoint supports when relevant penalties are zero. Defined false is a domain label rather than proof both reference sets are empty.
- 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
Compare methods only after aligning feature definitions, missingness, empty policies, multiplicities, and normalizers. Use a complete comparison when the tool returns only one contribution or count check.
References
Similar or alternative tools
- Similarity: Jaccard Empty Pair Policy
Compute cardinality-based Jaccard similarity with explicit zero/one empty-union convention and a retained defined flag.
- Similarity: Overlap Coefficient Empty Min Policy
Compute overlap coefficient from consistent finite-set cardinalities with an explicit empty-minimum convention and retained defined status.