f2dc2027f6
in the original GitHub fork: https://github.com/ntoronto/racket Some things about this are known to be broken (most egregious is that the array tests DO NOT RUN because of a problem in typed/rackunit), about half has no coverage in the tests, and half has no documentation. Fixes and docs are coming. This is committed now to allow others to find errors and inconsistency in the things that appear to be working, and to give the author a (rather incomplete) sense of closure.
38 lines
1.3 KiB
Racket
38 lines
1.3 KiB
Racket
#lang typed/racket/base
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(require racket/performance-hint
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"../../../flonum.rkt")
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(provide (all-defined-out))
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;; More correct than what the FPU comes up with:
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(define sqrt2pi.0 2.5066282746310007)
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(define 1/sqrt2pi.0 0.3989422804014327)
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(define logsqrt2pi.0 0.9189385332046728)
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(define -logsqrt2pi.0 (- logsqrt2pi.0))
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;; The largest input that returns a nonzero density:
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(define +standard-normal-pdf-max.0 38.58015760902841)
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;; The largest input that returns a nonzero log density:
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(define +standard-normal-log-pdf-max.0 1.8961503816218352e+154)
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;; The smallest input that returns a nonzero probability:
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(define -standard-normal-cdf-max.0 -38.485408335567335)
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;; The largest input that returns a non-one probability:
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(define +standard-normal-cdf-max.0 8.292361075813595)
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;; The smallest input that returns a finite log probability:
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(define -standard-normal-log-cdf-max.0 -1.8961503816218352e+154)
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;; The largest input that returns a nonzero log probability:
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(define +standard-normal-log-cdf-max.0 38.48540833595427)
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(begin-encourage-inline
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(: flexp-1/2*x^2 (Float -> Float))
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(define (flexp-1/2*x^2 x)
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(define trunc-x (fl/ (fltruncate (fl* (flexpt 2.0 21.0) x)) (flexpt 2.0 21.0)))
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(fl* (flexp (fl* (fl* -0.5 trunc-x) trunc-x))
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(flexp (fl* (fl* -0.5 (fl- x trunc-x)) (fl+ x trunc-x)))))
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) ; begin-encourage-inline
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