Struct PwlCurve

pub struct PwlCurve(/* private fields */);

A representation of a piecewise-linear, weakly monotone decreasing demand curve

Demand curves define a bidder’s willingness to pay for different quantities of a good. In flow trading, these curves must be:

• Piecewise-linear (defined by a sequence of points)
• Weakly monotone decreasing (price non-increasing as rate increases)
• Include the point rate=0 in their domain (must allow zero trade)

Unlike a ConstantCurve, all values (rates and prices) must be finite.

Implementations

impl PwlCurve

pub fn new(points: Vec<Point>) -> Result<Self, PwlCurveError>

Creates a new PwlCurve from a vector of points, validating all constraints

pub unsafe fn new_unchecked(points: Vec<Point>) -> Self

Creates a new PwlCurve without validating the points

Safety

This function bypasses all validation checks. The caller must guarantee that the points satisfy all requirements validated by PwlCurve::try_from. Using invalid points can lead to incorrect behavior in downstream systems, particularly in the solver which assumes valid monotone curves.

pub fn domain(&self) -> (f64, f64)

Returns the domain of the demand curve (min and max rates)

Returns

A tuple (min_rate, max_rate) where:

• min_rate is the rate of the first point (leftmost)
• max_rate is the rate of the last point (rightmost)

Panics

Panics if the curve has no points (which should never happen for a valid curve).

pub fn points(self) -> Vec<Point>

Converts the curve into its constituent points

This consumes the curve and returns the underlying vector of points. Useful for serialization or when the raw point data is needed.

Trait Implementations

impl Clone for PwlCurve

fn clone(&self) -> PwlCurve

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for PwlCurve

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

Formats the value using the given formatter.

impl From<PwlCurve> for DemandCurve

fn from(value: PwlCurve) -> Self

Converts to this type from the input type.

impl Into<PwlCurveDto> for PwlCurve

fn into(self) -> PwlCurveDto

Converts this type into the (usually inferred) input type.

impl TryFrom<PwlCurveDto> for PwlCurve

fn try_from(value: PwlCurveDto) -> Result<Self, Self::Error>

Attempts to create a PwlCurve from a DTO, validating all constraints

Validation

This function validates that:

1. The vector is not empty
2. No coordinate values are NaN
3. Points are ordered by ascending rate and descending price (monotonicity)
4. The curve domain includes rate=0 (allows zero trade)

Errors

Returns PwlCurveError if any validation fails.

type Error = PwlCurveError

The type returned in the event of a conversion error.