Struct LogarithmicMapping 

pub struct LogarithmicMapping { /* private fields */ }

Logarithmic index mapping.

Maps values to indices using: index = ceil(log(value) / log(gamma)) where gamma = (1 + alpha) / (1 - alpha) and alpha is the relative accuracy.

Implementations

impl LogarithmicMapping

pub fn new(relative_accuracy: f64) -> Result<Self, &'static str>

Creates a new LogarithmicMapping with the given relative accuracy.

The relative accuracy must be between 0 and 1 (inclusive).

Errors

If the relative accuracy is out of bounds, an error is returned.

Example

use ddsketch::canonical::mapping::LogarithmicMapping;

// Create a mapping with 1% relative accuracy
let mapping = LogarithmicMapping::new(0.01).unwrap();

pub fn new_with_gamma(gamma: f64) -> Result<Self, &'static str>

Creates a new LogarithmicMapping from an explicit logarithmic base.

This constructor is useful when the caller already knows the desired gamma and wants to build the mapping directly instead of deriving it from relative accuracy.

gamma must be greater than 1.0, otherwise the logarithmic mapping is invalid.

Errors

Returns an error if gamma <= 1.0.

pub fn new_with_gamma_and_offset( gamma: f64, index_offset: f64, ) -> Result<Self, &'static str>

Creates a new LogarithmicMapping from an explicit logarithmic base and index offset.

gamma must be greater than 1.0, otherwise the logarithmic mapping is invalid.

Errors

Returns an error if gamma <= 1.0.

Trait Implementations

impl Clone for LogarithmicMapping

fn clone(&self) -> LogarithmicMapping

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for LogarithmicMapping

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

Formats the value using the given formatter.

impl Default for LogarithmicMapping

fn default() -> Self

Creates a logarithmic mapping with 1% relative accuracy (the common default).

impl IndexMapping for LogarithmicMapping

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 LogarithmicMapping

fn eq(&self, other: &LogarithmicMapping) -> 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 StructuralPartialEq for LogarithmicMapping