exponent

Documentation

Index

• Constants
• func NewMapping(scale int32) (mapping.Mapping, error)

Constants

const (
	// MinScale defines the point at which the exponential mapping
	// function becomes useless for float64.  With scale -10, ignoring
	// subnormal values, bucket indices range from -1 to 1.
	MinScale int32 = -10

	// MaxScale is the largest scale supported in this code.  Use
	// ../logarithm for larger scales.
	MaxScale int32 = 0
)

const (
	// SignificandWidth is the size of an IEEE 754 double-precision
	// floating-point significand.
	SignificandWidth = 52
	// ExponentWidth is the size of an IEEE 754 double-precision
	// floating-point exponent.
	ExponentWidth = 11

	// SignificandMask is the mask for the significand of an IEEE 754
	// double-precision floating-point value: 0xFFFFFFFFFFFFF.
	SignificandMask = 1<<SignificandWidth - 1

	// ExponentBias is the exponent bias specified for encoding
	// the IEEE 754 double-precision floating point exponent: 1023.
	ExponentBias = 1<<(ExponentWidth-1) - 1

	// ExponentMask are set to 1 for the bits of an IEEE 754
	// floating point exponent: 0x7FF0000000000000.
	ExponentMask = ((1 << ExponentWidth) - 1) << SignificandWidth

	// SignMask selects the sign bit of an IEEE 754 floating point
	// number.
	SignMask = (1 << (SignificandWidth + ExponentWidth))

	// MinNormalExponent is the minimum exponent of a normalized
	// floating point: -1022.
	MinNormalExponent int32 = -ExponentBias + 1

	// MaxNormalExponent is the maximum exponent of a normalized
	// floating point: 1023.
	MaxNormalExponent int32 = ExponentBias

	// MinValue is the smallest normal number.
	MinValue = 0x1p-1022

	// MaxValue is the largest normal number.
	MaxValue = math.MaxFloat64
)

Functions

func NewMapping

func NewMapping(scale int32) (mapping.Mapping, error)

NewMapping constructs an exponential mapping function, used for scales <= 0.