Struct FixedLogarithmicMapping 

pub struct FixedLogarithmicMapping;

A zero-sized logarithmic index mapping with hardcoded 1% relative accuracy.

This mapping is functionally identical to LogarithmicMapping::new(0.01) but uses compile-time constants instead of storing gamma and multiplier as fields. This makes the type zero-sized, saving 16 bytes per DDSketch instance.

Use this mapping when you know all your sketches will use 1% relative accuracy (the common default).

Example

use ddsketch::canonical::mapping::FixedLogarithmicMapping;
use ddsketch::canonical::DDSketch;
use ddsketch::canonical::store::CollapsingLowestDenseStore;

// Create a sketch with the fixed mapping (saves 16 bytes vs LogarithmicMapping)
let sketch: DDSketch<FixedLogarithmicMapping, CollapsingLowestDenseStore> = DDSketch::default();

Implementations

impl FixedLogarithmicMapping

pub const fn new() -> Self

Creates a new FixedLogarithmicMapping.

This is a no-op since the type is zero-sized, but provided for API consistency.

Trait Implementations

impl Clone for FixedLogarithmicMapping

fn clone(&self) -> FixedLogarithmicMapping

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for FixedLogarithmicMapping

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for FixedLogarithmicMapping

fn default() -> FixedLogarithmicMapping

Returns the “default value” for a type.

impl Hash for FixedLogarithmicMapping

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl IndexMapping for FixedLogarithmicMapping

fn index(&self, value: f64) -> i32

Returns the index of the bin for the given positive value.

fn value(&self, index: i32) -> f64

Returns the representative value for the given index.

fn lower_bound(&self, index: i32) -> f64

Returns the lower bound of the bin at the given index.

fn relative_accuracy(&self) -> f64

Returns the relative accuracy of this mapping.

fn min_indexable_value(&self) -> f64

Returns the minimum positive value that can be indexed.

fn max_indexable_value(&self) -> f64

Returns the maximum positive value that can be indexed.

fn gamma(&self) -> f64

Returns the gamma value (base of the logarithm) for this mapping.

fn index_offset(&self) -> f64

Returns the index offset used by this mapping.

fn interpolation(&self) -> Interpolation

Returns the interpolation mode used by this mapping.

fn validate_proto_mapping( &self, proto: &ProtoIndexMapping, ) -> Result<(), ProtoConversionError>

Validates that a protobuf IndexMapping is compatible with this mapping.

fn to_proto(&self) -> ProtoIndexMapping

Converts this mapping to a protobuf IndexMapping.

impl PartialEq for FixedLogarithmicMapping

fn eq(&self, other: &FixedLogarithmicMapping) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Copy for FixedLogarithmicMapping

impl Eq for FixedLogarithmicMapping

impl StructuralPartialEq for FixedLogarithmicMapping