Arithmetic derivative: Difference between revisions

=={{header|Wren}}==

{{libheader|Wren-big}}

{{libheader|Wren-fmt}}

As integer arithmetic in Wren is inaccurate above 2^53 we need to use BigInt here.

<lang ecmascript>import "./big" for BigInt

import "./fmt" for Fmt

var D = Fn.new { |n|

if (n < 0) return -D.call(-n)

if (n < 2) return BigInt.zero

var f = BigInt.primeFactors(n)

var c = f.count

if (c == 1) return BigInt.one

if (c == 2) return f[0] + f[1]

var d = n / f[0]

return D.call(d) * f[0] + d

}

var ad = List.filled(200, 0)

for (n in -99..100) ad[n+99] = D.call(BigInt.new(n))

Fmt.tprint("$4i", ad, 10)

System.print()

for (m in 1..20) {

Fmt.print("D(10^$-2d) / 7 = $i", m, D.call(BigInt.ten.pow(m))/7)

}</lang>

{{out}}

<pre>

-75 -77 -1 -272 -24 -49 -34 -96 -20 -123

-1 -140 -32 -45 -22 -124 -1 -43 -108 -176

-1 -71 -18 -80 -55 -39 -1 -156 -1 -59

-26 -72 -1 -61 -18 -192 -51 -33 -1 -92

-1 -31 -22 -92 -16 -81 -1 -56 -20 -45

-14 -112 -1 -25 -39 -48 -1 -41 -1 -68

-16 -21 -1 -60 -12 -19 -14 -80 -1 -31

-1 -32 -27 -15 -10 -44 -1 -13 -10 -24

-1 -21 -1 -32 -8 -9 -1 -16 -1 -7

-6 -12 -1 -5 -1 -4 -1 -1 0 0

0 1 1 4 1 5 1 12 6 7

1 16 1 9 8 32 1 21 1 24

10 13 1 44 10 15 27 32 1 31

1 80 14 19 12 60 1 21 16 68

1 41 1 48 39 25 1 112 14 45

20 56 1 81 16 92 22 31 1 92

1 33 51 192 18 61 1 72 26 59

1 156 1 39 55 80 18 71 1 176

108 43 1 124 22 45 32 140 1 123

20 96 34 49 24 272 1 77 75 140

D(10^1 ) / 7 = 1

D(10^2 ) / 7 = 20

D(10^3 ) / 7 = 300

D(10^4 ) / 7 = 4000

D(10^5 ) / 7 = 50000

D(10^6 ) / 7 = 600000

D(10^7 ) / 7 = 7000000

D(10^8 ) / 7 = 80000000

D(10^9 ) / 7 = 900000000

D(10^10) / 7 = 10000000000

D(10^11) / 7 = 110000000000

D(10^12) / 7 = 1200000000000

D(10^13) / 7 = 13000000000000

D(10^14) / 7 = 140000000000000

D(10^15) / 7 = 1500000000000000

D(10^16) / 7 = 16000000000000000

D(10^17) / 7 = 170000000000000000

D(10^18) / 7 = 1800000000000000000

D(10^19) / 7 = 19000000000000000000

D(10^20) / 7 = 200000000000000000000

</pre>