Description
Calculate intersection/(intersection+alpha*leftOnly+beta*rightOnly) and return that value as both forward and reverseWithSwappedWeights.
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.
Calculate intersection/(intersection+alpha*leftOnly+beta*rightOnly) and return that value as both forward and reverseWithSwappedWeights.
When to use this tool
Use Tversky Parameter Swap Duality 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. Use the units and conventions below.
- Run the tool. Correct any format, range, or cross-field input error before interpreting the output.
- Read forward, reverseWithSwappedWeights. Use the output convention below.
Calculate intersection/(intersection+alpha*leftOnly+beta*rightOnly) and return that value as both forward and reverseWithSwappedWeights. Require nonnegative integer counts, nonnegative penalties, and positive denominator.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. |
| Output field | Interpretation | Returned shape |
|---|---|---|
| forward | Forward | Required. Finite number. |
| reverseWithSwappedWeights | Same computed value by stated duality; no second calculation. | Required. Finite number. |
{
"input": {
"intersection": 2,
"leftOnly": 2,
"rightOnly": 0,
"alpha": 1,
"beta": 2
},
"output": {
"forward": 0.5,
"reverseWithSwappedWeights": 0.5
}
}Limitations and assumptions
- The second output states duality under swapping both set roles and penalty roles; it is not independently recomputed. No actual sets or weight-selection criteria are checked.
- 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
- Tversky Alpha Beta Swap Gap
Compare swapping the asymmetry weights of one supplied Tversky overlap.
- Tversky One Sided Penalty Parameter
Calculate Tversky score and alphaDerivative=-intersection*firstOnly/denominator² from denominator=intersection+alpha*firstOnly+beta*secondOnly.