ModalType

new ModalType(parameters)

Description:

• Specifies a level of truth, tau, between -1 (false), 0 (unknown) and 1 (true).

  Extends: Type. This class extends Type, with all public methods available.

  Type parameters

  General parameter

  • name: ... The type name. By default the type name is "modal".

  Parameters for the semantic projection

  • trinary: ... If true only the false (-1), unknown (0), and true (1) values are considered, without intermediate value.
  • binary: ... If true only the false (-1) and true (1) values are considered, without intermediate value.

  Parameters for the distance evaluation

  • step: ... The normalization of the distance |lhs-rhs|/step where step is the neighborhood size.
    • By default 2.

  Parameters for the geodesic calculation

  • atomic: ...
    • If true returns only an atomic path with the two left-hand and right-hand elements. Default is true.
    • If false returns a path with all intermediate values, step by step, or precision value by precision value if step is undefined.

  ModalType specification

  Syntactic projection	- Returns NAN if not a parsable number. - Returns the zero if an empty value. - The value "true" (numerically 1), "false" (numerically -1) and "unknown" or '?' (numerically 0) are understood.
  Semantic projection	- If the value is higher than 1 it is set to true. - If the value is lower than -1 it is set to false. - If precision is defined the value is projected to the closest min + k precision value, k being an integer. - If in trinary mode, values are projected onto the closest {-1, 0, 1} value.      v <- v < -0.5 ? -1 : v > 0.5 ? 1 : 0 - If in binary mode, values are projected onto the closest {-1, 1} value.      v <- v <= 0 ? -1 : 1
  Distance value	The distance is calculated as a weighted value |lhs-rhs|/step. - It is INFINITY if not both object are numeric.
  Geodesic path	The geodesic is assumed to be atomic, i.e. of length 1 if value are equal and 2 if different.
  Comparison	- Returns either lhs-rhs or 0 if the precision is defined and |lhs-rhs| < precision.
  Bounds	- `[-1, 1]` are the bounds.

  Note:

  • It is implemented as a NumericType({ ... min: -1 max: 1 step: 2 atomic: true}).
  • This representation is in one to one correspondence with possibility and necessity modal logic as implemented using getPi(), getNu() and getTau().
  • This representation is compatible with 2D modal logic as implemented using getTau() and getRho().
  • Usual Boolean operations are generalized to modal value as implemented in getOp().

Parameters:

Name	Type	Description
parameters	JSON | String	The type parameters.