math: factorial submodule

pull/3208/head
Ulises Jeremias Cornejo Fandos 2019-12-27 00:08:17 -03:00 committed by Alexander Medvednikov
parent a5b43e1f4d
commit 1277ce22f8
6 changed files with 468 additions and 196 deletions

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@ -1,177 +0,0 @@
module math
const (
factorials = [f64(1.000000000000000000000e+0),/* 0! */
1.000000000000000000000e+0,/* 1! */
2.000000000000000000000e+0,/* 2! */
6.000000000000000000000e+0,/* 3! */
2.400000000000000000000e+1,/* 4! */
1.200000000000000000000e+2,/* 5! */
7.200000000000000000000e+2,/* 6! */
5.040000000000000000000e+3,/* 7! */
4.032000000000000000000e+4,/* 8! */
3.628800000000000000000e+5,/* 9! */
3.628800000000000000000e+6,/* 10! */
3.991680000000000000000e+7,/* 11! */
4.790016000000000000000e+8,/* 12! */
6.227020800000000000000e+9,/* 13! */
8.717829120000000000000e+10,/* 14! */
1.307674368000000000000e+12,/* 15! */
2.092278988800000000000e+13,/* 16! */
3.556874280960000000000e+14,/* 17! */
6.402373705728000000000e+15,/* 18! */
1.216451004088320000000e+17,/* 19! */
2.432902008176640000000e+18,/* 20! */
5.109094217170944000000e+19,/* 21! */
1.124000727777607680000e+21,/* 22! */
2.585201673888497664000e+22,/* 23! */
6.204484017332394393600e+23,/* 24! */
1.551121004333098598400e+25,/* 25! */
4.032914611266056355840e+26,/* 26! */
1.088886945041835216077e+28,/* 27! */
3.048883446117138605015e+29,/* 28! */
8.841761993739701954544e+30,/* 29! */
2.652528598121910586363e+32,/* 30! */
8.222838654177922817726e+33,/* 31! */
2.631308369336935301672e+35,/* 32! */
8.683317618811886495518e+36,/* 33! */
2.952327990396041408476e+38,/* 34! */
1.033314796638614492967e+40,/* 35! */
3.719933267899012174680e+41,/* 36! */
1.376375309122634504632e+43,/* 37! */
5.230226174666011117600e+44,/* 38! */
2.039788208119744335864e+46,/* 39! */
8.159152832478977343456e+47,/* 40! */
3.345252661316380710817e+49,/* 41! */
1.405006117752879898543e+51,/* 42! */
6.041526306337383563736e+52,/* 43! */
2.658271574788448768044e+54,/* 44! */
1.196222208654801945620e+56,/* 45! */
5.502622159812088949850e+57,/* 46! */
2.586232415111681806430e+59,/* 47! */
1.241391559253607267086e+61,/* 48! */
6.082818640342675608723e+62,/* 49! */
3.041409320171337804361e+64,/* 50! */
1.551118753287382280224e+66,/* 51! */
8.065817517094387857166e+67,/* 52! */
4.274883284060025564298e+69,/* 53! */
2.308436973392413804721e+71,/* 54! */
1.269640335365827592597e+73,/* 55! */
7.109985878048634518540e+74,/* 56! */
4.052691950487721675568e+76,/* 57! */
2.350561331282878571829e+78,/* 58! */
1.386831185456898357379e+80,/* 59! */
8.320987112741390144276e+81,/* 60! */
5.075802138772247988009e+83,/* 61! */
3.146997326038793752565e+85,/* 62! */
1.982608315404440064116e+87,/* 63! */
1.268869321858841641034e+89,/* 64! */
8.247650592082470666723e+90,/* 65! */
5.443449390774430640037e+92,/* 66! */
3.647111091818868528825e+94,/* 67! */
2.480035542436830599601e+96,/* 68! */
1.711224524281413113725e+98,/* 69! */
1.197857166996989179607e+100,/* 70! */
8.504785885678623175212e+101,/* 71! */
6.123445837688608686152e+103,/* 72! */
4.470115461512684340891e+105,/* 73! */
3.307885441519386412260e+107,/* 74! */
2.480914081139539809195e+109,/* 75! */
1.885494701666050254988e+111,/* 76! */
1.451830920282858696341e+113,/* 77! */
1.132428117820629783146e+115,/* 78! */
8.946182130782975286851e+116,/* 79! */
7.156945704626380229481e+118,/* 80! */
5.797126020747367985880e+120,/* 81! */
4.753643337012841748421e+122,/* 82! */
3.945523969720658651190e+124,/* 83! */
3.314240134565353266999e+126,/* 84! */
2.817104114380550276949e+128,/* 85! */
2.422709538367273238177e+130,/* 86! */
2.107757298379527717214e+132,/* 87! */
1.854826422573984391148e+134,/* 88! */
1.650795516090846108122e+136,/* 89! */
1.485715964481761497310e+138,/* 90! */
1.352001527678402962552e+140,/* 91! */
1.243841405464130725548e+142,/* 92! */
1.156772507081641574759e+144,/* 93! */
1.087366156656743080274e+146,/* 94! */
1.032997848823905926260e+148,/* 95! */
9.916779348709496892096e+149,/* 96! */
9.619275968248211985333e+151,/* 97! */
9.426890448883247745626e+153,/* 98! */
9.332621544394415268170e+155,/* 99! */
9.332621544394415268170e+157,/* 100! */
9.425947759838359420852e+159,/* 101! */
9.614466715035126609269e+161,/* 102! */
9.902900716486180407547e+163,/* 103! */
1.029901674514562762385e+166,/* 104! */
1.081396758240290900504e+168,/* 105! */
1.146280563734708354534e+170,/* 106! */
1.226520203196137939352e+172,/* 107! */
1.324641819451828974500e+174,/* 108! */
1.443859583202493582205e+176,/* 109! */
1.588245541522742940425e+178,/* 110! */
1.762952551090244663872e+180,/* 111! */
1.974506857221074023537e+182,/* 112! */
2.231192748659813646597e+184,/* 113! */
2.543559733472187557120e+186,/* 114! */
2.925093693493015690688e+188,/* 115! */
3.393108684451898201198e+190,/* 116! */
3.969937160808720895402e+192,/* 117! */
4.684525849754290656574e+194,/* 118! */
5.574585761207605881323e+196,/* 119! */
6.689502913449127057588e+198,/* 120! */
8.094298525273443739682e+200,/* 121! */
9.875044200833601362412e+202,/* 122! */
1.214630436702532967577e+205,/* 123! */
1.506141741511140879795e+207,/* 124! */
1.882677176888926099744e+209,/* 125! */
2.372173242880046885677e+211,/* 126! */
3.012660018457659544810e+213,/* 127! */
3.856204823625804217357e+215,/* 128! */
4.974504222477287440390e+217,/* 129! */
6.466855489220473672507e+219,/* 130! */
8.471580690878820510985e+221,/* 131! */
1.118248651196004307450e+224,/* 132! */
1.487270706090685728908e+226,/* 133! */
1.992942746161518876737e+228,/* 134! */
2.690472707318050483595e+230,/* 135! */
3.659042881952548657690e+232,/* 136! */
5.012888748274991661035e+234,/* 137! */
6.917786472619488492228e+236,/* 138! */
9.615723196941089004197e+238,/* 139! */
1.346201247571752460588e+241,/* 140! */
1.898143759076170969429e+243,/* 141! */
2.695364137888162776589e+245,/* 142! */
3.854370717180072770522e+247,/* 143! */
5.550293832739304789551e+249,/* 144! */
8.047926057471991944849e+251,/* 145! */
1.174997204390910823948e+254,/* 146! */
1.727245890454638911203e+256,/* 147! */
2.556323917872865588581e+258,/* 148! */
3.808922637630569726986e+260,/* 149! */
5.713383956445854590479e+262,/* 150! */
8.627209774233240431623e+264,/* 151! */
1.311335885683452545607e+267,/* 152! */
2.006343905095682394778e+269,/* 153! */
3.089769613847350887959e+271,/* 154! */
4.789142901463393876336e+273,/* 155! */
7.471062926282894447084e+275,/* 156! */
1.172956879426414428192e+278,/* 157! */
1.853271869493734796544e+280,/* 158! */
2.946702272495038326504e+282,/* 159! */
4.714723635992061322407e+284,/* 160! */
7.590705053947218729075e+286,/* 161! */
1.229694218739449434110e+289,/* 162! */
2.004401576545302577600e+291,/* 163! */
3.287218585534296227263e+293,/* 164! */
5.423910666131588774984e+295,/* 165! */
9.003691705778437366474e+297,/* 166! */
1.503616514864999040201e+300,/* 167! */
2.526075744973198387538e+302,/* 168! */
4.269068009004705274939e+304,/* 169! */
7.257415615307998967397e+306/* 170! */
]
)

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@ -0,0 +1,80 @@
// Copyright (c) 2019 Alexander Medvednikov. All rights reserved.
// Use of this source code is governed by an MIT license
// that can be found in the LICENSE file.
// Module created by Ulises Jeremias Cornejo Fandos based on
// the definitions provided in https://scientificc.github.io/cmathl/
module factorial
import math
// factorial calculates the factorial of the provided value.
pub fn factorial(n f64) f64 {
// For a large postive argument (n >= FACTORIALS.len) return max_f64
if n >= FACTORIALS.len {
return math.max_f64
}
// Otherwise return n!.
if n == f64(i64(n)) && n >= 0.0 {
return FACTORIALS[i64(n)]
}
return math.gamma(n + 1.0)
}
// log_factorial calculates the log-factorial of the provided value.
pub fn log_factorial(n f64) f64 {
// For a large postive argument (n < 0) return max_f64
if n < 0 {
return -math.max_f64
}
// If n < N then return ln(n!).
if n != f64(i64(n)) {
return math.log_gamma(n+1)
} else if n < LOG_FACTORIALS.len {
return LOG_FACTORIALS[i64(n)]
}
// Otherwise return asymptotic expansion of ln(n!).
return log_factorial_asymptotic_expansion(int(n))
}
fn log_factorial_asymptotic_expansion(n int) f64 {
m := 6
mut term := []f64
xx := f64((n + 1) * (n + 1))
mut xj := f64(n + 1)
log_factorial := log_sqrt_2pi - xj + (xj - 0.5) * math.log(xj)
mut i := 0
for i = 0; i < m; i++ {
term << B[i] / xj
xj *= xx
}
mut sum := term[m-1]
for i = m - 2; i >= 0; i-- {
if math.abs(sum) <= math.abs(term[i]) {
break
}
sum = term[i]
}
for i >= 0 {
sum += term[i]
i--
}
return log_factorial + sum
}

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@ -0,0 +1,374 @@
// Copyright (c) 2019 Alexander Medvednikov. All rights reserved.
// Use of this source code is governed by an MIT license
// that can be found in the LICENSE file.
module factorial
const (
log_sqrt_2pi = 9.18938533204672741780329736e-1
B = [
/* Bernoulli numbers B(2),B(4),B(6),...,B(20). Only B(2),...,B(10) currently
* used.
*/
f64(1.0 / (6.0 * 2.0 * 1.0)),
-1.0 / (30.0 * 4.0 * 3.0),
1.0 / (42.0 * 6.0 * 5.0),
-1.0 / (30.0 * 8.0 * 7.0),
5.0 / (66.0 * 10.0 * 9.0),
-691.0 / (2730.0 * 12.0 * 11.0),
7.0 / (6.0 * 14.0 * 13.0),
-3617.0 / (510.0 * 16.0 * 15.0),
43867.0 / (796.0 * 18.0 * 17.0),
-174611.0 / (330.0 * 20.0 * 19.0)
]
FACTORIALS = [
f64(1.000000000000000000000e+0), /* 0! */
1.000000000000000000000e+0, /* 1! */
2.000000000000000000000e+0, /* 2! */
6.000000000000000000000e+0, /* 3! */
2.400000000000000000000e+1, /* 4! */
1.200000000000000000000e+2, /* 5! */
7.200000000000000000000e+2, /* 6! */
5.040000000000000000000e+3, /* 7! */
4.032000000000000000000e+4, /* 8! */
3.628800000000000000000e+5, /* 9! */
3.628800000000000000000e+6, /* 10! */
3.991680000000000000000e+7, /* 11! */
4.790016000000000000000e+8, /* 12! */
6.227020800000000000000e+9, /* 13! */
8.717829120000000000000e+10, /* 14! */
1.307674368000000000000e+12, /* 15! */
2.092278988800000000000e+13, /* 16! */
3.556874280960000000000e+14, /* 17! */
6.402373705728000000000e+15, /* 18! */
1.216451004088320000000e+17, /* 19! */
2.432902008176640000000e+18, /* 20! */
5.109094217170944000000e+19, /* 21! */
1.124000727777607680000e+21, /* 22! */
2.585201673888497664000e+22, /* 23! */
6.204484017332394393600e+23, /* 24! */
1.551121004333098598400e+25, /* 25! */
4.032914611266056355840e+26, /* 26! */
1.088886945041835216077e+28, /* 27! */
3.048883446117138605015e+29, /* 28! */
8.841761993739701954544e+30, /* 29! */
2.652528598121910586363e+32, /* 30! */
8.222838654177922817726e+33, /* 31! */
2.631308369336935301672e+35, /* 32! */
8.683317618811886495518e+36, /* 33! */
2.952327990396041408476e+38, /* 34! */
1.033314796638614492967e+40, /* 35! */
3.719933267899012174680e+41, /* 36! */
1.376375309122634504632e+43, /* 37! */
5.230226174666011117600e+44, /* 38! */
2.039788208119744335864e+46, /* 39! */
8.159152832478977343456e+47, /* 40! */
3.345252661316380710817e+49, /* 41! */
1.405006117752879898543e+51, /* 42! */
6.041526306337383563736e+52, /* 43! */
2.658271574788448768044e+54, /* 44! */
1.196222208654801945620e+56, /* 45! */
5.502622159812088949850e+57, /* 46! */
2.586232415111681806430e+59, /* 47! */
1.241391559253607267086e+61, /* 48! */
6.082818640342675608723e+62, /* 49! */
3.041409320171337804361e+64, /* 50! */
1.551118753287382280224e+66, /* 51! */
8.065817517094387857166e+67, /* 52! */
4.274883284060025564298e+69, /* 53! */
2.308436973392413804721e+71, /* 54! */
1.269640335365827592597e+73, /* 55! */
7.109985878048634518540e+74, /* 56! */
4.052691950487721675568e+76, /* 57! */
2.350561331282878571829e+78, /* 58! */
1.386831185456898357379e+80, /* 59! */
8.320987112741390144276e+81, /* 60! */
5.075802138772247988009e+83, /* 61! */
3.146997326038793752565e+85, /* 62! */
1.982608315404440064116e+87, /* 63! */
1.268869321858841641034e+89, /* 64! */
8.247650592082470666723e+90, /* 65! */
5.443449390774430640037e+92, /* 66! */
3.647111091818868528825e+94, /* 67! */
2.480035542436830599601e+96, /* 68! */
1.711224524281413113725e+98, /* 69! */
1.197857166996989179607e+100, /* 70! */
8.504785885678623175212e+101, /* 71! */
6.123445837688608686152e+103, /* 72! */
4.470115461512684340891e+105, /* 73! */
3.307885441519386412260e+107, /* 74! */
2.480914081139539809195e+109, /* 75! */
1.885494701666050254988e+111, /* 76! */
1.451830920282858696341e+113, /* 77! */
1.132428117820629783146e+115, /* 78! */
8.946182130782975286851e+116, /* 79! */
7.156945704626380229481e+118, /* 80! */
5.797126020747367985880e+120, /* 81! */
4.753643337012841748421e+122, /* 82! */
3.945523969720658651190e+124, /* 83! */
3.314240134565353266999e+126, /* 84! */
2.817104114380550276949e+128, /* 85! */
2.422709538367273238177e+130, /* 86! */
2.107757298379527717214e+132, /* 87! */
1.854826422573984391148e+134, /* 88! */
1.650795516090846108122e+136, /* 89! */
1.485715964481761497310e+138, /* 90! */
1.352001527678402962552e+140, /* 91! */
1.243841405464130725548e+142, /* 92! */
1.156772507081641574759e+144, /* 93! */
1.087366156656743080274e+146, /* 94! */
1.032997848823905926260e+148, /* 95! */
9.916779348709496892096e+149, /* 96! */
9.619275968248211985333e+151, /* 97! */
9.426890448883247745626e+153, /* 98! */
9.332621544394415268170e+155, /* 99! */
9.332621544394415268170e+157, /* 100! */
9.425947759838359420852e+159, /* 101! */
9.614466715035126609269e+161, /* 102! */
9.902900716486180407547e+163, /* 103! */
1.029901674514562762385e+166, /* 104! */
1.081396758240290900504e+168, /* 105! */
1.146280563734708354534e+170, /* 106! */
1.226520203196137939352e+172, /* 107! */
1.324641819451828974500e+174, /* 108! */
1.443859583202493582205e+176, /* 109! */
1.588245541522742940425e+178, /* 110! */
1.762952551090244663872e+180, /* 111! */
1.974506857221074023537e+182, /* 112! */
2.231192748659813646597e+184, /* 113! */
2.543559733472187557120e+186, /* 114! */
2.925093693493015690688e+188, /* 115! */
3.393108684451898201198e+190, /* 116! */
3.969937160808720895402e+192, /* 117! */
4.684525849754290656574e+194, /* 118! */
5.574585761207605881323e+196, /* 119! */
6.689502913449127057588e+198, /* 120! */
8.094298525273443739682e+200, /* 121! */
9.875044200833601362412e+202, /* 122! */
1.214630436702532967577e+205, /* 123! */
1.506141741511140879795e+207, /* 124! */
1.882677176888926099744e+209, /* 125! */
2.372173242880046885677e+211, /* 126! */
3.012660018457659544810e+213, /* 127! */
3.856204823625804217357e+215, /* 128! */
4.974504222477287440390e+217, /* 129! */
6.466855489220473672507e+219, /* 130! */
8.471580690878820510985e+221, /* 131! */
1.118248651196004307450e+224, /* 132! */
1.487270706090685728908e+226, /* 133! */
1.992942746161518876737e+228, /* 134! */
2.690472707318050483595e+230, /* 135! */
3.659042881952548657690e+232, /* 136! */
5.012888748274991661035e+234, /* 137! */
6.917786472619488492228e+236, /* 138! */
9.615723196941089004197e+238, /* 139! */
1.346201247571752460588e+241, /* 140! */
1.898143759076170969429e+243, /* 141! */
2.695364137888162776589e+245, /* 142! */
3.854370717180072770522e+247, /* 143! */
5.550293832739304789551e+249, /* 144! */
8.047926057471991944849e+251, /* 145! */
1.174997204390910823948e+254, /* 146! */
1.727245890454638911203e+256, /* 147! */
2.556323917872865588581e+258, /* 148! */
3.808922637630569726986e+260, /* 149! */
5.713383956445854590479e+262, /* 150! */
8.627209774233240431623e+264, /* 151! */
1.311335885683452545607e+267, /* 152! */
2.006343905095682394778e+269, /* 153! */
3.089769613847350887959e+271, /* 154! */
4.789142901463393876336e+273, /* 155! */
7.471062926282894447084e+275, /* 156! */
1.172956879426414428192e+278, /* 157! */
1.853271869493734796544e+280, /* 158! */
2.946702272495038326504e+282, /* 159! */
4.714723635992061322407e+284, /* 160! */
7.590705053947218729075e+286, /* 161! */
1.229694218739449434110e+289, /* 162! */
2.004401576545302577600e+291, /* 163! */
3.287218585534296227263e+293, /* 164! */
5.423910666131588774984e+295, /* 165! */
9.003691705778437366474e+297, /* 166! */
1.503616514864999040201e+300, /* 167! */
2.526075744973198387538e+302, /* 168! */
4.269068009004705274939e+304, /* 169! */
7.257415615307998967397e+306 /* 170! */
]
LOG_FACTORIALS = [
f64(0.000000000000000000000e+0), /* 0! */
0.000000000000000000000e+0, /* 1! */
6.931471805599453094172e-1, /* 2! */
1.791759469228055000812e+0, /* 3! */
3.178053830347945619647e+0, /* 4! */
4.787491742782045994248e+0, /* 5! */
6.579251212010100995060e+0, /* 6! */
8.525161361065414300166e+0, /* 7! */
1.060460290274525022842e+1, /* 8! */
1.280182748008146961121e+1, /* 9! */
1.510441257307551529523e+1, /* 10! */
1.750230784587388583929e+1, /* 11! */
1.998721449566188614952e+1, /* 12! */
2.255216385312342288557e+1, /* 13! */
2.519122118273868150009e+1, /* 14! */
2.789927138384089156609e+1, /* 15! */
3.067186010608067280376e+1, /* 16! */
3.350507345013688888401e+1, /* 17! */
3.639544520803305357622e+1, /* 18! */
3.933988418719949403622e+1, /* 19! */
4.233561646075348502966e+1, /* 20! */
4.538013889847690802616e+1, /* 21! */
4.847118135183522387964e+1, /* 22! */
5.160667556776437357045e+1, /* 23! */
5.478472939811231919009e+1, /* 24! */
5.800360522298051993929e+1, /* 25! */
6.126170176100200198477e+1, /* 26! */
6.455753862700633105895e+1, /* 27! */
6.788974313718153498289e+1, /* 28! */
7.125703896716800901007e+1, /* 29! */
7.465823634883016438549e+1, /* 30! */
7.809222355331531063142e+1, /* 31! */
8.155795945611503717850e+1, /* 32! */
8.505446701758151741396e+1, /* 33! */
8.858082754219767880363e+1, /* 34! */
9.213617560368709248333e+1, /* 35! */
9.571969454214320248496e+1, /* 36! */
9.933061245478742692933e+1, /* 37! */
1.029681986145138126988e+2, /* 38! */
1.066317602606434591262e+2, /* 39! */
1.103206397147573954291e+2, /* 40! */
1.140342117814617032329e+2, /* 41! */
1.177718813997450715388e+2, /* 42! */
1.215330815154386339623e+2, /* 43! */
1.253172711493568951252e+2, /* 44! */
1.291239336391272148826e+2, /* 45! */
1.329525750356163098828e+2, /* 46! */
1.368027226373263684696e+2, /* 47! */
1.406739236482342593987e+2, /* 48! */
1.445657439463448860089e+2, /* 49! */
1.484777669517730320675e+2, /* 50! */
1.524095925844973578392e+2, /* 51! */
1.563608363030787851941e+2, /* 52! */
1.603311282166309070282e+2, /* 53! */
1.643201122631951814118e+2, /* 54! */
1.683274454484276523305e+2, /* 55! */
1.723527971391628015638e+2, /* 56! */
1.763958484069973517152e+2, /* 57! */
1.804562914175437710518e+2, /* 58! */
1.845338288614494905025e+2, /* 59! */
1.886281734236715911873e+2, /* 60! */
1.927390472878449024360e+2, /* 61! */
1.968661816728899939914e+2, /* 62! */
2.010093163992815266793e+2, /* 63! */
2.051681994826411985358e+2, /* 64! */
2.093425867525368356464e+2, /* 65! */
2.135322414945632611913e+2, /* 66! */
2.177369341139542272510e+2, /* 67! */
2.219564418191303339501e+2, /* 68! */
2.261905483237275933323e+2, /* 69! */
2.304390435657769523214e+2, /* 70! */
2.347017234428182677427e+2, /* 71! */
2.389783895618343230538e+2, /* 72! */
2.432688490029827141829e+2, /* 73! */
2.475729140961868839366e+2, /* 74! */
2.518904022097231943772e+2, /* 75! */
2.562211355500095254561e+2, /* 76! */
2.605649409718632093053e+2, /* 77! */
2.649216497985528010421e+2, /* 78! */
2.692910976510198225363e+2, /* 79! */
2.736731242856937041486e+2, /* 80! */
2.780675734403661429141e+2, /* 81! */
2.824742926876303960274e+2, /* 82! */
2.868931332954269939509e+2, /* 83! */
2.913239500942703075662e+2, /* 84! */
2.957666013507606240211e+2, /* 85! */
3.002209486470141317540e+2, /* 86! */
3.046868567656687154726e+2, /* 87! */
3.091641935801469219449e+2, /* 88! */
3.136528299498790617832e+2, /* 89! */
3.181526396202093268500e+2, /* 90! */
3.226634991267261768912e+2, /* 91! */
3.271852877037752172008e+2, /* 92! */
3.317178871969284731381e+2, /* 93! */
3.362611819791984770344e+2, /* 94! */
3.408150588707990178690e+2, /* 95! */
3.453794070622668541074e+2, /* 96! */
3.499541180407702369296e+2, /* 97! */
3.545390855194408088492e+2, /* 98! */
3.591342053695753987760e+2, /* 99! */
3.637393755555634901441e+2, /* 100! */
3.683544960724047495950e+2, /* 101! */
3.729794688856890206760e+2, /* 102! */
3.776141978739186564468e+2, /* 103! */
3.822585887730600291111e+2, /* 104! */
3.869125491232175524822e+2, /* 105! */
3.915759882173296196258e+2, /* 106! */
3.962488170517915257991e+2, /* 107! */
4.009309482789157454921e+2, /* 108! */
4.056222961611448891925e+2, /* 109! */
4.103227765269373054205e+2, /* 110! */
4.150323067282496395563e+2, /* 111! */
4.197508055995447340991e+2, /* 112! */
4.244781934182570746677e+2, /* 113! */
4.292143918666515701285e+2, /* 114! */
4.339593239950148201939e+2, /* 115! */
4.387129141861211848399e+2, /* 116! */
4.434750881209189409588e+2, /* 117! */
4.482457727453846057188e+2, /* 118! */
4.530248962384961351041e+2, /* 119! */
4.578123879812781810984e+2, /* 120! */
4.626081785268749221865e+2, /* 121! */
4.674121995716081787447e+2, /* 122! */
4.722243839269805962399e+2, /* 123! */
4.770446654925856331047e+2, /* 124! */
4.818729792298879342285e+2, /* 125! */
4.867092611368394122258e+2, /* 126! */
4.915534482232980034989e+2, /* 127! */
4.964054784872176206648e+2, /* 128! */
5.012652908915792927797e+2, /* 129! */
5.061328253420348751997e+2, /* 130! */
5.110080226652360267439e+2, /* 131! */
5.158908245878223975982e+2, /* 132! */
5.207811737160441513633e+2, /* 133! */
5.256790135159950627324e+2, /* 134! */
5.305842882944334921812e+2, /* 135! */
5.354969431801695441897e+2, /* 136! */
5.404169241059976691050e+2, /* 137! */
5.453441777911548737966e+2, /* 138! */
5.502786517242855655538e+2, /* 139! */
5.552202941468948698523e+2, /* 140! */
5.601690540372730381305e+2, /* 141! */
5.651248810948742988613e+2, /* 142! */
5.700877257251342061414e+2, /* 143! */
5.750575390247102067619e+2, /* 144! */
5.800342727671307811636e+2, /* 145! */
5.850178793888391176022e+2, /* 146! */
5.900083119756178539038e+2, /* 147! */
5.950055242493819689670e+2, /* 148! */
6.000094705553274281080e+2, /* 149! */
6.050201058494236838580e+2, /* 150! */
6.100373856862386081868e+2, /* 151! */
6.150612662070848845750e+2, /* 152! */
6.200917041284773200381e+2, /* 153! */
6.251286567308909491967e+2, /* 154! */
6.301720818478101958172e+2, /* 155! */
6.352219378550597328635e+2, /* 156! */
6.402781836604080409209e+2, /* 157! */
6.453407786934350077245e+2, /* 158! */
6.504096828956552392500e+2, /* 159! */
6.554848567108890661717e+2, /* 160! */
6.605662610758735291676e+2, /* 161! */
6.656538574111059132426e+2, /* 162! */
6.707476076119126755767e+2, /* 163! */
6.758474740397368739994e+2, /* 164! */
6.809534195136374546094e+2, /* 165! */
6.860654073019939978423e+2, /* 166! */
6.911834011144107529496e+2, /* 167! */
6.963073650938140118743e+2, /* 168! */
7.014372638087370853465e+2, /* 169! */
7.065730622457873471107e+2, /* 170! */
7.117147258022900069535e+2, /* 171! */
]
)

View File

@ -0,0 +1,14 @@
import math
import math.factorial as fact
fn test_factorial() {
assert fact.factorial(12) == 479001600
assert fact.factorial(5) == 120
assert fact.factorial(0) == 1
}
fn test_log_factorial() {
assert fact.log_factorial(12) == math.log(479001600)
assert fact.log_factorial(5) == math.log(120)
assert fact.log_factorial(0) == math.log(1)
}

View File

@ -181,19 +181,6 @@ pub fn exp2(a f64) f64 {
return C.exp2(a)
}
// factorial calculates the factorial of the provided value.
pub fn factorial(n f64) f64 {
// For a large postive argument (n >= factorials.len) return max_f64
if n >= factorials.len {
return max_f64
}
// Otherwise return n!.
if n == f64(i64(n)) && n >= 0.0 {
return factorials[i64(n)]
}
return gamma(n + 1.0)
}
// floor returns the nearest f64 lower or equal of the provided value.
pub fn floor(a f64) f64 {
return C.floor(a)

View File

@ -27,12 +27,6 @@ fn test_digits() {
assert negative_digits[2] == -1
}
fn test_factorial() {
assert factorial(12) == 479001600
assert factorial(5) == 120
assert factorial(0) == 1
}
fn test_erf() {
assert erf(0) == 0
assert erf(1.5) + erf(-1.5) == 0