Struct descent::expr::dynam::Expr

pub struct Expr { /* private fields */ }

An expression that can be dynamically constructed.

Operator overloading is implemented for this struct alongside Var, Par and f64. Once the final expression has been constructed, it can be converted into a ExprDyn, which locks down the final form of the expression, and calculates some additional information about its “sparsity” (which is expensive to do, some only done once).

An Expr shouldn’t be directly constructed, instead it is produced by applying a valid operator (+, -, *, powi, sin, cos) to either an existing operator, or to a Var or Par value.

use descent::expr::{Var, Par};
use descent::expr::dynam::NumOps; // required to bring in powi usage
let x = Var(0);
let y = Var(1);
let p = Par(0);

let e = p * x - (5.0 * y.powi(2) + 4.0); // this produces an `Expr`

One exception to this is for convenience, e.g., summing a bunch of terms:

use descent::expr::Var;
use descent::expr::dynam::Expr;
let xs: Vec<Var> = (0..5).into_iter().map(|i| Var(i)).collect();

let mut e = Expr::from(0.0);
for &x in &xs {
    e = e + x;
}

Implementations

impl Expr

pub fn eval<R>(&self, ret: &R, ns: &mut Vec<f64>) -> f64where
    R: Retrieve,

Value of the expression.

pub fn get_info(&self) -> ExprInfo

Get information about the expression.

pub fn len(&self) -> usize

pub fn is_empty(&self) -> bool

Trait Implementations

impl<'a> Add<&'a Expr> for Par

type Output = Expr

The resulting type after applying the + operator.

fn add(self, other: &'a Expr) -> Expr

Performs the + operation.

impl<'a> Add<&'a Expr> for Var

type Output = Expr

The resulting type after applying the + operator.

fn add(self, other: &'a Expr) -> Expr

Performs the + operation.

impl<'a> Add<&'a Expr> for f64

type Output = Expr

The resulting type after applying the + operator.

fn add(self, other: &'a Expr) -> Expr

Performs the + operation.

impl Add<Expr> for Expr

type Output = Expr

The resulting type after applying the + operator.

fn add(self, other: Expr) -> Expr

Performs the + operation.

impl Add<Expr> for ExprDynSum

type Output = Vec<ExprDyn, Global>

The resulting type after applying the + operator.

fn add(self, other: Expr) -> ExprDynSum

Performs the + operation.

impl Add<Expr> for Par

type Output = Expr

The resulting type after applying the + operator.

fn add(self, other: Expr) -> Expr

Performs the + operation.

impl Add<Expr> for Var

type Output = Expr

The resulting type after applying the + operator.

fn add(self, other: Expr) -> Expr

Performs the + operation.

impl Add<Expr> for f64

type Output = Expr

The resulting type after applying the + operator.

fn add(self, other: Expr) -> Expr

Performs the + operation.

impl<'a> Add<Par> for &'a Expr

type Output = Expr

The resulting type after applying the + operator.

fn add(self, other: Par) -> Expr

Performs the + operation.

impl Add<Par> for Expr

type Output = Expr

The resulting type after applying the + operator.

fn add(self, other: Par) -> Expr

Performs the + operation.

impl<'a> Add<Var> for &'a Expr

type Output = Expr

The resulting type after applying the + operator.

fn add(self, other: Var) -> Expr

Performs the + operation.

impl Add<Var> for Expr

type Output = Expr

The resulting type after applying the + operator.

fn add(self, other: Var) -> Expr

Performs the + operation.

impl Add<Vec<ExprDyn, Global>> for Expr

type Output = Vec<ExprDyn, Global>

The resulting type after applying the + operator.

fn add(self, other: ExprDynSum) -> ExprDynSum

Performs the + operation.

impl<'a> Add<f64> for &'a Expr

type Output = Expr

The resulting type after applying the + operator.

fn add(self, other: f64) -> Expr

Performs the + operation.

impl Add<f64> for Expr

type Output = Expr

The resulting type after applying the + operator.

fn add(self, other: f64) -> Expr

Performs the + operation.

impl Clone for Expr

fn clone(&self) -> Expr

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for Expr

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

Formats the value using the given formatter.

impl From<Expr> for ExprDyn

fn from(expr: Expr) -> Self

Converts to this type from the input type.

impl From<Expr> for Expression

fn from(expr: Expr) -> Self

Converts to this type from the input type.

impl From<Par> for Expr

fn from(p: Par) -> Expr

Converts to this type from the input type.

impl From<Var> for Expr

fn from(v: Var) -> Expr

Converts to this type from the input type.

impl From<f64> for Expr

fn from(v: f64) -> Expr

Converts to this type from the input type.

impl From<i32> for Expr

fn from(v: i32) -> Expr

Converts to this type from the input type.

impl<'a> Mul<&'a Expr> for Par

type Output = Expr

The resulting type after applying the * operator.

fn mul(self, other: &'a Expr) -> Expr

Performs the * operation.

impl<'a> Mul<&'a Expr> for Var

type Output = Expr

The resulting type after applying the * operator.

fn mul(self, other: &'a Expr) -> Expr

Performs the * operation.

impl<'a> Mul<&'a Expr> for f64

type Output = Expr

The resulting type after applying the * operator.

fn mul(self, other: &'a Expr) -> Expr

Performs the * operation.

impl Mul<Expr> for Expr

type Output = Expr

The resulting type after applying the * operator.

fn mul(self, other: Expr) -> Expr

Performs the * operation.

impl Mul<Expr> for Par

type Output = Expr

The resulting type after applying the * operator.

fn mul(self, other: Expr) -> Expr

Performs the * operation.

impl Mul<Expr> for Var

type Output = Expr

The resulting type after applying the * operator.

fn mul(self, other: Expr) -> Expr

Performs the * operation.

impl Mul<Expr> for f64

type Output = Expr

The resulting type after applying the * operator.

fn mul(self, other: Expr) -> Expr

Performs the * operation.

impl<'a> Mul<Par> for &'a Expr

type Output = Expr

The resulting type after applying the * operator.

fn mul(self, other: Par) -> Expr

Performs the * operation.

impl Mul<Par> for Expr

type Output = Expr

The resulting type after applying the * operator.

fn mul(self, other: Par) -> Expr

Performs the * operation.

impl<'a> Mul<Var> for &'a Expr

type Output = Expr

The resulting type after applying the * operator.

fn mul(self, other: Var) -> Expr

Performs the * operation.

impl Mul<Var> for Expr

type Output = Expr

The resulting type after applying the * operator.

fn mul(self, other: Var) -> Expr

Performs the * operation.

impl<'a> Mul<f64> for &'a Expr

type Output = Expr

The resulting type after applying the * operator.

fn mul(self, other: f64) -> Expr

Performs the * operation.

impl Mul<f64> for Expr

type Output = Expr

The resulting type after applying the * operator.

fn mul(self, other: f64) -> Expr

Performs the * operation.

impl NumOps for Expr

fn powi(self, p: i32) -> Expr

fn sin(self) -> Expr

fn cos(self) -> Expr

impl<'a> Sub<&'a Expr> for Par

type Output = Expr

The resulting type after applying the - operator.

fn sub(self, other: &'a Expr) -> Expr

Performs the - operation.

impl<'a> Sub<&'a Expr> for Var

type Output = Expr

The resulting type after applying the - operator.

fn sub(self, other: &'a Expr) -> Expr

Performs the - operation.

impl<'a> Sub<&'a Expr> for f64

type Output = Expr

The resulting type after applying the - operator.

fn sub(self, other: &'a Expr) -> Expr

Performs the - operation.

impl Sub<Expr> for Expr

type Output = Expr

The resulting type after applying the - operator.

fn sub(self, other: Expr) -> Expr

Performs the - operation.

impl Sub<Expr> for Par

type Output = Expr

The resulting type after applying the - operator.

fn sub(self, other: Expr) -> Expr

Performs the - operation.

impl Sub<Expr> for Var

type Output = Expr

The resulting type after applying the - operator.

fn sub(self, other: Expr) -> Expr

Performs the - operation.

impl Sub<Expr> for f64

type Output = Expr

The resulting type after applying the - operator.

fn sub(self, other: Expr) -> Expr

Performs the - operation.

impl<'a> Sub<Par> for &'a Expr

type Output = Expr

The resulting type after applying the - operator.

fn sub(self, other: Par) -> Expr

Performs the - operation.

impl Sub<Par> for Expr

type Output = Expr

The resulting type after applying the - operator.

fn sub(self, other: Par) -> Expr

Performs the - operation.

impl<'a> Sub<Var> for &'a Expr

type Output = Expr

The resulting type after applying the - operator.

fn sub(self, other: Var) -> Expr

Performs the - operation.

impl Sub<Var> for Expr

type Output = Expr

The resulting type after applying the - operator.

fn sub(self, other: Var) -> Expr

Performs the - operation.

impl<'a> Sub<f64> for &'a Expr

type Output = Expr

The resulting type after applying the - operator.

fn sub(self, other: f64) -> Expr

Performs the - operation.

impl Sub<f64> for Expr

type Output = Expr

The resulting type after applying the - operator.

fn sub(self, other: f64) -> Expr

Performs the - operation.