Qnum

A set of static methods for working with qualified numbers. The internal representation of a qualified number is a regular double precision floating point number (IEEE 754), except the two least significant bits in mantissa are reserved for holding the qualifier ([LESS], [EXACT], [GREATER]).

The advantage of that representation is that the standard arithmetic operations could be performed directly on the number, without unpacking it. This is especially important for batch operations such as aggregation or sorting. While there is a loss of precision, it is rather insignificant (50 bits for storing mantissa instead of 52), which makes perfect sense considering that qualified numbers represent imprecise measurements.

Use [create], [getValue], and [getQ] methods for packing/unpacking.

Constructors

new Qnum()

new Qnum(): Qnum

Returns

Qnum

Methods

create()

static create(value, q): number

Creates a QNum value out of the [value] and qualifier [q].

Parameters

Parameter	Type	Default value	Description
value	number	undefined
q	number	QNUM_EXACT

Returns

number

Source

src/dataframe.ts:2248

---

exact()

static exact(x): number

Parameters

Parameter	Type
x	number

Returns

number

Source

src/dataframe.ts:2255

---

getQ()

static getQ(x): number

Extracts the qualifier (QNUM_LESS, QNUM_EXACT, QNUM_GREATER). See also getValue

Parameters

Parameter	Type	Description
x	number

Returns

number

Source

src/dataframe.ts:2224

---

getValue()

static getValue(x): number

Extracts the value from x, stripping the qualifier . See also getQ

Parameters

Parameter	Type	Description
x	number

Returns

number

Source

src/dataframe.ts:2235

---

greater()

static greater(x): number

Parameters

Parameter	Type
x	number

Returns

number

Source

src/dataframe.ts:2263

---

less()

static less(x): number

Parameters

Parameter	Type
x	number

Returns

number

Source

src/dataframe.ts:2259

---

parse()

static parse(s): number

Parses a string into a qualified number.

Parameters

Parameter	Type	Description
s	string

Returns

number

Source

src/dataframe.ts:2272

---

qualifier()

static qualifier(x): string

Returns the string representation of the qualifier.

Parameters

Parameter	Type	Description
x	number

Returns

string

Source

src/dataframe.ts:2290

---

toString()

static toString(x): string

Converts a qualified number to a string representation.

Parameters

Parameter	Type	Description
x	number

Returns

string

Source

src/dataframe.ts:2281