PhyslibAlpha.ProbabilisticTheory.Effect.Convex
Convexity and mixtures of effects
i. Overview
The effect interval `[0, 1]` is convex: randomizing between two effects with some probability gives back an effect. Physically, flipping a biased coin to decide which of two measurements to actually run is itself a legitimate measurement.
ii. Key results
- `Effect.convex` : the effect interval is convex.
- `Effect.mix` : randomize between two effects with a given probability.
iii. Table of contents
- A. Convexity and mixtures of effects
A. Convexity and mixtures of effects
3 declarations
Convexity of the set of effects
The set of effects in a type , denoted as `Effect E` and defined as the order interval , is a convex set over the real numbers .
Mixture of effects
For a type with a partial order, a zero element , and a unit element , let and be **effects** (elements in the order interval ). Given a value in the unit interval , this function returns the **mixture** of and , which is the effect defined by the convex combination . This represents randomizing between the two effects with probability of testing the first.
Mixture of effects is the convex combination
For any two effects in the interval and a probability in the unit interval , the mixture of and with parameter is equal to the convex combination: where the equality holds for the corresponding elements in the underlying type .
