Struct CtrCurve 

pub struct CtrCurve { /* private fields */ }

A CTR-by-position curve built from observed data.

Positions are stored as whole-number buckets (position 3.4 falls in bucket 3). Each bucket accumulates clicks and impressions, so the curve’s CTR for a bucket is the real pooled rate of the data you fed it, never an assumed constant.

Implementations

impl CtrCurve

pub fn new() -> Self

An empty curve.

pub fn observe( &mut self, position: f64, clicks: u64, impressions: u64, ) -> Result<(), SerpError>

Fold one observation into the curve.

Non-finite or sub-1.0 positions are rejected with SerpError::InvalidPosition, and inconsistent rows with SerpError::ClicksExceedImpressions.

pub fn from_observations<I>(observations: I) -> Result<Self, SerpError>

where I: IntoIterator<Item = (f64, u64, u64)>,

Build a curve from an iterator of (position, clicks, impressions) observations.

pub fn len(&self) -> usize

Number of populated position buckets.

pub fn is_empty(&self) -> bool

Whether the curve holds no observations.

pub fn impressions_at(&self, position: u32) -> u64

Total impressions observed for a bucket, or 0 if the bucket is absent.

pub fn ctr_at(&self, position: u32) -> Result<f64, SerpError>

Pooled CTR observed at a whole-number position.

Errors

SerpError::PositionNotInCurve when nothing was ever observed at that position, and SerpError::NoImpressions when the bucket exists but holds zero impressions. The curve never interpolates or extrapolates: an unobserved position is an error, not a guess.

pub fn points(&self) -> Vec<(u32, f64)>

Every populated bucket as (position, ctr), ascending by position.

Buckets holding zero impressions are skipped, because they have no rate.

pub fn project_clicks( &self, position: u32, impressions: u64, ) -> Result<u64, SerpError>

Clicks you would expect from impressions at position, using this curve.

The result is impressions * ctr_at(position), rounded to the nearest whole click. It is a restatement of your own observed rate at a volume you supply — it is not a forecast, and it says nothing about whether that position is reachable.

Errors

Propagates the errors of CtrCurve::ctr_at.

pub fn projected_click_delta( &self, from: u32, to: u32, impressions: u64, ) -> Result<i64, SerpError>

Difference in projected clicks between two positions at the same impression volume.

Positive when to earns more than from.

Errors

Propagates the errors of CtrCurve::ctr_at for either position.

Trait Implementations

impl Clone for CtrCurve

fn clone(&self) -> CtrCurve

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for CtrCurve

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

Formats the value using the given formatter.

impl Default for CtrCurve

fn default() -> CtrCurve

Returns the “default value” for a type.

impl Eq for CtrCurve

impl PartialEq for CtrCurve

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for CtrCurve