Math/Complex.bruijn
# ideas by u/DaVinci103
# MIT License, Copyright (c) 2024 Marvin Borner
:import std/Combinator .
:import std/Pair .
:import std/Math/Real R
ι (+0.0+1.0i)
# converts a balanced ternary number to a complex number
number→complex [[0 (R.number→real 1) (+0.0r)]] ⧗ Number → Complex
:test (number→complex (+5)) ((+5.0+0.0i))
# returns real part of a complex number
real fst ⧗ Complex → Real
:test (real (+5.0+2.0i)) ((+5.0r))
# returns imaginary part of a complex number
imag snd ⧗ Complex → Real
:test (imag (+5.0+2.0i)) ((+2.0r))
# approximates complex number by turning it into a pair of rationals
approx &[[[(2 0) : (1 0)]]] ⧗ Complex → Number → (Pair Rational Rational)
:test (approx (+5.0+2.0i) (+2)) ((+5.0q) : (+2.0q))
# returns true if two complex numbers are equal approximately
approx-eq? [[[R.approx-eq? 2 (1 2) (0 2)]]] ⧗ Number → Complex → Complex → Boolean
# TODO: bigger value (higher performance first!)
…≈?… approx-eq? (+1000)
# adds two complex numbers
add &[[&[[(R.add 3 1) : (R.add 2 0)]]]] ⧗ Complex → Complex → Complex
…+… add
# subtracts two complex numbers
sub &[[&[[(R.sub 3 1) : (R.sub 2 0)]]]] ⧗ Complex → Complex → Complex
…+… sub
# multiplies two complex numbers
mul &[[&[[p : q]]]] ⧗ Complex → Complex → Complex
p R.sub (R.mul 3 1) (R.mul 2 0)
q R.add (R.mul 3 0) (R.mul 2 1)
…⋅… mul
# divides two complex numbers
div &[[&[[p : q]]]] ⧗ Complex → Complex → Complex
p R.div (R.add (R.mul 3 1) (R.mul 2 0)) (R.add (R.mul 1 1) (R.mul 0 0))
q R.div (R.sub (R.mul 2 1) (R.mul 1 0)) (R.add (R.mul 1 1) (R.mul 0 0))
…/… div
# negates a complex number
negate &[[(R.negate 1) : (R.negate 0)]] ⧗ Complex → Complex
-‣ negate
# inverts a complex number
invert &[[p : q]] ⧗ Complex → Complex
p R.div 1 (R.add (R.mul 1 1) (R.mul 0 0))
q R.div 0 (R.add (R.mul 1 1) (R.mul 0 0))
~‣ invert
# ---
:import std/List L
# power function: complex^number
pow-n [L.nth-iterate (mul 0) (+1.0+0.0i)] ⧗ Complex → Number → Complex
ln [p : q] ⧗ Complex → Complex
p R.ln (&R.hypot 0)
q &R.atan2 0