2d34811ab6
Fixed a few limit cases in some distributions (e.g. (uniform-dist 0 0) didn't act like a delta distribution, (beta-dist 0 0) and (beta-dist +inf.0 +inf.0) pretended to be defined by unique limits even though they can't be) Made integer distributions' pdfs return +nan.0 when given non-integers Added "private/statistics/counting.rkt", for hashing and binning samples Added `flvector-sums' (cumulative sums with single rounding error) Added `flinteger?', `flnan?' and `flrational?', which are faster than their non-flonum counterparts (at least in Typed Racket; haven't tested untyped)
24 lines
753 B
Racket
24 lines
753 B
Racket
#lang typed/racket/base
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(require "../../../flonum.rkt"
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"../../functions/beta.rkt")
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(provide flbeta-log-pdf)
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(: flbeta-log-pdf (Flonum Flonum Flonum -> Flonum))
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(define (flbeta-log-pdf a b x)
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(cond [(or (a . fl< . 0.0) (b . fl< . 0.0)
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(and (fl= a 0.0) (fl= b 0.0))
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(and (fl= a +inf.0) (fl= b +inf.0)))
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+nan.0]
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[(or (fl= a 0.0) (fl= b +inf.0))
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(if (fl= x 0.0) +inf.0 -inf.0)]
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[(or (fl= b 0.0) (fl= a +inf.0))
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(if (fl= x 1.0) +inf.0 -inf.0)]
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[(or (x . fl< . 0.0) (x . fl> . 1.0))
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-inf.0]
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[else
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(flsum (list (fl* (fl- a 1.0) (fllog x))
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(fl* (fl- b 1.0) (fllog1p (- x)))
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(- (fllog-beta a b))))]))
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