Struct s2::s1::chordangle::ChordAngle

pub struct ChordAngle(pub f64);

ChordAngle represents the angle subtended by a chord (i.e., the straight line segment connecting two points on the sphere). Its representation makes it very efficient for computing and comparing distances, but unlike Angle it is only capable of representing angles between 0 and π radians. Generally, ChordAngle should only be used in loops where many angles need to be calculated and compared. Otherwise it is simpler to use Angle.

ChordAngle loses some accuracy as the angle approaches π radians. Specifically, the representation of (π - x) radians has an error of about (1e-15 / x), with a maximum error of about 2e-8 radians (about 13cm on the Earth’s surface). For comparison, for angles up to π/2 radians (10000km) the worst-case representation error is about 2e-16 radians (1 nanonmeter), which is about the same as Angle.

ChordAngles are represented by the squared chord length, which can range from 0 to 4. Positive infinity represents an infinite squared length.

Tuple Fields

0: f64

Implementations

impl ChordAngle

pub fn inf() -> Self

inf returns a chord angle larger than any finite chord angle. The only valid operations on an InfChordAngle are comparisons and Angle conversions.

pub fn is_infinite(&self) -> bool

is_infinite reports whether this ChordAngle is infinite.

pub fn from_squared_length(length2: f64) -> Self

from_squared_length returns a ChordAngle from the squared chord length. Note that the argument is automatically clamped to a maximum of 4.0 to handle possible roundoff errors. The argument must be non-negative.

pub fn expanded(&self, e: f64) -> Self

expanded returns a new ChordAngle that has been adjusted by the given error bound (which can be positive or negative). Error should be the value returned by either MaxPointError or MaxAngleError. For example: let a = ChordAngle::from_points(x, y) let a1 = a.expanded(a.max_point_error())

pub fn is_special(&self) -> bool

is_special reports whether this ChordAngle is one of the special cases.

pub fn is_valid(&self) -> bool

is_valid reports whether this ChordAngle is valid or not.

pub fn max(self, other: Self) -> Self

pub fn max_point_error(&self) -> f64

max_point_error returns the maximum error size for a ChordAngle constructed from 2 Points x and y, assuming that x and y are normalized to within the bounds guaranteed by s2.Point.Normalize. The error is defined with respect to the true distance after the points are projected to lie exactly on the sphere.

pub fn max_angle_error(&self) -> f64

max_angle_error returns the maximum error for a ChordAngle constructed as an Angle distance.

pub fn sin(&self) -> f64

sin returns the sine of this chord angle. This method is more efficient than converting to Angle and performing the computation.

pub fn sin2(&self) -> f64

sin2 returns the square of the sine of this chord angle. It is more efficient than Sin.

pub fn cos(&self) -> f64

cos returns the cosine of this chord angle. This method is more efficient than converting to Angle and performing the computation.

pub fn tan(&self) -> f64

tan returns the tangent of this chord angle.

pub fn successor(&self) -> Self

Trait Implementations

impl<'a, 'b> Add<&'a ChordAngle> for &'b ChordAngle

fn add(self, other: &'a ChordAngle) -> Self::Output

add adds the other ChordAngle to this one and returns the resulting value. This method assumes the ChordAngles are not special.

type Output = ChordAngle

The resulting type after applying the + operator.

impl Add<ChordAngle> for ChordAngle

type Output = ChordAngle

The resulting type after applying the + operator.

fn add(self, other: ChordAngle) -> Self::Output

Performs the + operation.

impl Clone for ChordAngle

fn clone(&self) -> ChordAngle

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for ChordAngle

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

Formats the value using the given formatter.

impl Default for ChordAngle

fn default() -> ChordAngle

Returns the “default value” for a type.

impl<'de> Deserialize<'de> for ChordAngle

fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error>where
    __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl<'a> From<&'a Angle> for ChordAngle

fn from(a: &'a Angle) -> Self

returns a ChordAngle from the given Angle.

impl<'a> From<&'a ChordAngle> for Angle

fn from(ca: &'a ChordAngle) -> Self

converts this ChordAngle to an Angle.

impl<'a> From<&'a Deg> for ChordAngle

fn from(a: &'a Deg) -> Self

Converts to this type from the input type.

impl From<Angle> for ChordAngle

fn from(a: Angle) -> Self

returns a ChordAngle from the given Angle.

impl From<ChordAngle> for Angle

fn from(ca: ChordAngle) -> Self

converts this ChordAngle to an Angle.

impl From<Deg> for ChordAngle

fn from(a: Deg) -> Self

Converts to this type from the input type.

impl PartialEq<ChordAngle> for ChordAngle

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

This method tests for self and other values to be equal, and is used by ==.

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

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

impl PartialOrd<ChordAngle> for ChordAngle

fn partial_cmp(&self, other: &ChordAngle) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

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

This method tests less than (for self and other) and is used by the < operator.

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

This method tests less than or equal to (for self and other) and is used by the <= operator.

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

This method tests greater than (for self and other) and is used by the > operator.

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

This method tests greater than or equal to (for self and other) and is used by the >= operator.

impl Serialize for ChordAngle

fn serialize<__S>(&self, __serializer: __S) -> Result<__S::Ok, __S::Error>where
    __S: Serializer,

Serialize this value into the given Serde serializer.

impl Sub<ChordAngle> for ChordAngle

fn sub(self, other: ChordAngle) -> Self::Output

sub subtracts the other ChordAngle from this one and returns the resulting value. This method assumes the ChordAngles are not special.

type Output = ChordAngle

The resulting type after applying the - operator.

impl Copy for ChordAngle

impl StructuralPartialEq for ChordAngle