3 Engines

9.1

Racket

3 Engines🔗ℹ

An engine provides a backend for performing inference. By default, Roulette automatically installs the RSDD backend.

3.1 RSDD🔗ℹ

procedure
(rsdd-engine [#:semiring s])
→ (engine/c (immutable-set/c any/c) s)
s : semiring? = real-semiring

Performs inference over the s semiring using RSDD. When an engine is garbage collected, all the memory associated with it (i.e., BDDs and weights) is freed.

> (define complex-engine (rsdd-engine #:semiring complex-semiring))
> (define polynomial-engine (rsdd-engine #:semiring polynomial-semiring))

procedure
(bernoulli-measure f t [#:semiring s])
→ (measure/c (immutable-set/c boolean?) s)
  f : s
  t : s
  s : semiring? = real-semiring

Returns a measure such that (set) gets (semiring-zero s), (set #f) gets f, (set #t) gets t, and (set #f #t) gets ((semiring-plus s) f t).

> (define-measurable x
(bernoulli-measure 0+1i 1 #:semiring complex-semiring))
> ((infer x #:engine complex-engine) (set #f #t))
1.0+1.0i
> (define-measurable y
(bernoulli-measure '(0.1 0.6) '(0.9 0.4) #:semiring polynomial-semiring))
> ((infer y #:engine polynomial-engine) (set #f #t))
'(1.0 1.0)

procedure
(semiring? v) → boolean?
v : any/c

Recognizes a semiring instance. A semiring acts like a contract that recognizes elements of the semiring.

value
real-semiring : semiring?
value
complex-semiring : semiring?
value
polynomial-semiring : semiring?

Semirings that can be used with RSDD.