Struct SvdTruncationPolicy 

pub struct SvdTruncationPolicy {
    pub threshold: f64,
    pub scale: ThresholdScale,
    pub measure: SingularValueMeasure,
    pub rule: TruncationRule,
}

Explicit truncation policy for SVD-based decompositions.

Use this type when you need to describe how singular values are measured, scaled, and turned into a retained rank. SvdOptions carries this policy plus an independent max_rank cap.

Examples

use tensor4all_core::{
    SingularValueMeasure, SvdTruncationPolicy, ThresholdScale, TruncationRule,
};

let policy = SvdTruncationPolicy::new(1e-12);
assert_eq!(policy.scale, ThresholdScale::Relative);
assert_eq!(policy.measure, SingularValueMeasure::Value);
assert_eq!(policy.rule, TruncationRule::PerValue);

let tail_policy = SvdTruncationPolicy::new(1e-8)
    .with_absolute()
    .with_squared_values()
    .with_discarded_tail_sum();
assert_eq!(tail_policy.scale, ThresholdScale::Absolute);
assert_eq!(tail_policy.measure, SingularValueMeasure::SquaredValue);
assert_eq!(tail_policy.rule, TruncationRule::DiscardedTailSum);

Fields

threshold: f64

Threshold value used by the selected scale/rule combination.

scale: ThresholdScale

Whether the threshold is interpreted relatively or absolutely.

measure: SingularValueMeasure

Whether the policy measures singular values or squared singular values.

rule: TruncationRule

Whether truncation is per value or based on a discarded tail sum.

Implementations

impl SvdTruncationPolicy

pub const fn new(threshold: f64) -> Self

Create a policy with the default semantics: relative threshold, singular values, and per-value truncation.

pub const fn with_relative(self) -> Self

Use relative threshold scaling.

pub const fn with_absolute(self) -> Self

Use absolute threshold scaling.

pub const fn with_values(self) -> Self

Measure singular values directly.

pub const fn with_squared_values(self) -> Self

Measure squared singular values.

pub const fn with_per_value(self) -> Self

Apply the threshold independently to each singular value.

pub const fn with_discarded_tail_sum(self) -> Self

Apply the threshold to the cumulative discarded tail.

Trait Implementations

impl Clone for SvdTruncationPolicy

fn clone(&self) -> SvdTruncationPolicy

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for SvdTruncationPolicy

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

Formats the value using the given formatter.

impl PartialEq for SvdTruncationPolicy

fn eq(&self, other: &SvdTruncationPolicy) -> 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 SvdTruncationPolicy

impl StructuralPartialEq for SvdTruncationPolicy