Symbol - Documentation

new Symbol(nameopt, tauopt, sigmaopt)

Description:

Creates a macroscopic ersatz of a VSA symbol.
- For convenience the constructs
  - Symbol(String name, double tau, double sigma)
  - Symbol(String name, const Belief& belief)
- Note: a symbol can not be copied, use the clone() method instead.

Parameters:

Name Type Attributes Default Description

Name	Type	Attributes	Default	Description
`name`	String \| Symbol	<optional>		The symbol name. If omitted, the name is set to `#id` where `id` is an automatic unique number, see getID(). If given as a symbol, the symbol name is used.
`tau`	double	<optional>	`1`	The symbol degree of belief.
`sigma`	double	<optional>	`0`	The symbol standard-deviation of the related level of noise.

name

String | Symbol

The symbol name.

If omitted, the name is set to #id where id is an automatic unique number, see getID().
If given as a symbol, the symbol name is used.

tau

double

1

The symbol degree of belief.

sigma

double

0

The symbol standard-deviation of the related level of noise.

Members

(static) nill :Symbol

Description:

The nill symbol, with the empty string as name, with tau=0.

The nill symbol, with the empty string as name, with tau=0.

Type:

Symbol

Methods

getName() → {String}

Description:

Returns the symbol name.

Returns:

The read-only symbol name value.

Type: String

getID() → {uint}

Description:

Returns the symbol ID.
- This ID is a unique number for a given symbol.
  - Two atomic symbols with the same ID are equal, possibly with different belief level.
  - This does not apply to non atomic symbols: binding or bundling.

Returns:

The read-only symbol id value.

Type: uint

getType() → {SymbolType}

Description:

Returns the symbol type.

Returns:

Either Symbol::SymbolType::atomic, Symbol::SymbolType::binding, or Symbol::SymbolType::bundling.

Type: SymbolType

getVector() → {Array}

Description:

Returns a randomly drawn unary vector coresponding to this symbol.

Returns:

The double[] read-only symbol vector value.

Type: Array

getBelief()()

Returns:

The degree of belief

tau between -1 (false), 0 (unknown) and true (1), 1 by default and
sigma the standard-deviation of the related level of noise, 0 by default.

setBelief()(belief)

Parameters:

Name	Type	Description
`belief`	Belief	The degree of belief, the `setBelief(tau, sigma)` is also available.

equals(symbol, whatopt) → {bool}

Description:

Tests if two symbol are indistiguishable.
- Two symbols are ``colinear´´ if they have the same corresponds to the same vector, up to the magnitude.
- Two symbols are ``indistiguishable´´ if colinear and with the same belief, up to some precision:
  `|tau - symbol.tau| < 2 |sigma_0 + sigma + symbol.sigma|
- The == C++ operator corresponds to indistiguishable.

Parameters:

Name	Type	Attributes	Default	Description
`symbol`	Symbol			The symbol to compare with this one.
`what`	char	<optional>	`'i'`	either 'c' for colinear or 'i' for indistiguishable

Returns:

True if equal, false otherwise.

Type: bool

asString() → {String}

Description:

Returns the value as a string.

Returns:

A string of the form name<tau+-sigma>:

omitting the belief if tau=1, sigma=0,
adding the _type if it is an unexpected _bundling or a _binding symbol.

Type: String

(static) getDimension() → {uint}

Description:

Returns the underlying VSA space dimension.

Returns:

The VSA space dimension, default value is d=10000.

Type: uint

(static) setDimension(dopt)

Description:

Changes the underlying VSA space dimension.
- All computed values are reseted.

Parameters:

Name	Type	Attributes	Default	Description
`d`	uint	<optional>	`10000`	The new VSA space dimension. It must be a square of an integer.

(static) clone(symbol, tauopt, sigmaopt) → {Symbol}

Description:

Properly clone a atomic, binding or bundling symbol, possibly with a different belief.
- The created symbol is available until program end.
- The clone(const Symbol& symbol, const Belief& belief) form is also available.

Parameters:

Name	Type	Attributes	Default	Description
`symbol`	Symbol			The symbol to compare with this one.
`tau`	double	<optional>	`1`	The symbol degree of belief.
`sigma`	double	<optional>	`0`	The symbol standard-deviation of the related level of noise.

Returns:

A pointer to the new symbol to be deleted after use.

Type: Symbol

(static) fromJSON(symbol) → {Symbol}

Description:

Parses a weak json string to generate a symbol.
- In order to input expression we use the usual JSON syntax in a weak form, namely:
  - Bundlings are represented by lists:
    [symbol_1 ...].
  - Bindings are represented by the construct:
    {b y: symbol x: symbol },
    where b stands for binding and is replaced by u for unbinding.
  - Atomic symbols are represented by the construct:
    { name: symbol-name tau: tau-value sigma: tau-value }, <br/> tauandsigmabeing optional, while atomic symbols withtau=1andsigma=0` are also represented by strings.

Parameters:

Name	Type	Description
`symbol`	JSON \| string	The weak json string to parse.

Returns:

A reference to the built symbol.

The built symbol is editable and remanent, i.e., available until program end.

Type: Symbol

(static) toJSON(symbol) → {string}

Description:

Returns a symbol using the weak JSON syntax of the fromJSON.

Parameters:

Name	Type	Description
`symbol`	Symbol	The symbol to encode in JSON.

Returns:

The weak JSON syntax output.

Type: string

(static) dump()

Description:

Prints on stdout, for debugging and statistics purposes, global informations on symbol data.