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This means it might contain formatting issues, incorrect code, conceptual problems, or other severe issues.
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{{task|Arithmetic operations}}
The purpose of this task is to explore working with [https://en.wikipedia.org/wiki/Complex_number complex numbers].
;Task: Given n, find the n-th [[wp:Roots of unity|roots of unity]].
Ada
with Ada.Text_IO; use Ada.Text_IO;
with Ada.Float_Text_IO; use Ada.Float_Text_IO;
with Ada.Numerics.Complex_Types; use Ada.Numerics.Complex_Types;
procedure Roots_Of_Unity is
Root : Complex;
begin
for N in 2..10 loop
Put_Line ("N =" & Integer'Image (N));
for K in 0..N - 1 loop
Root :=
Compose_From_Polar
( Modulus => 1.0,
Argument => Float (K),
Cycle => Float (N)
);
-- Output
Put (" k =" & Integer'Image (K) & ", ");
if Re (Root) < 0.0 then
Put ("-");
else
Put ("+");
end if;
Put (abs Re (Root), Fore => 1, Exp => 0);
if Im (Root) < 0.0 then
Put ("-");
else
Put ("+");
end if;
Put (abs Im (Root), Fore => 1, Exp => 0);
Put_Line ("i");
end loop;
end loop;
end Roots_Of_Unity;
[[Ada]] provides a direct implementation of polar composition of complex numbers ''x e''2π''i y''. The function Compose_From_Polar is used to compose roots. The third argument of the function is the cycle. Instead of the standard cycle 2π, N is used. Sample output:
N = 2
k = 0, +1.00000+0.00000i
k = 1, -1.00000+0.00000i
N = 3
k = 0, +1.00000+0.00000i
k = 1, -0.50000+0.86603i
k = 2, -0.50000-0.86603i
N = 4
k = 0, +1.00000+0.00000i
k = 1, +0.00000+1.00000i
k = 2, -1.00000+0.00000i
k = 3, +0.00000-1.00000i
N = 5
k = 0, +1.00000+0.00000i
k = 1, +0.30902+0.95106i
k = 2, -0.80902+0.58779i
k = 3, -0.80902-0.58779i
k = 4, +0.30902-0.95106i
N = 6
k = 0, +1.00000+0.00000i
k = 1, +0.50000+0.86603i
k = 2, -0.50000+0.86603i
k = 3, -1.00000+0.00000i
k = 4, -0.50000-0.86603i
k = 5, +0.50000-0.86603i
N = 7
k = 0, +1.00000+0.00000i
k = 1, +0.62349+0.78183i
k = 2, -0.22252+0.97493i
k = 3, -0.90097+0.43388i
k = 4, -0.90097-0.43388i
k = 5, -0.22252-0.97493i
k = 6, +0.62349-0.78183i
N = 8
k = 0, +1.00000+0.00000i
k = 1, +0.70711+0.70711i
k = 2, +0.00000+1.00000i
k = 3, -0.70711+0.70711i
k = 4, -1.00000+0.00000i
k = 5, -0.70711-0.70711i
k = 6, +0.00000-1.00000i
k = 7, +0.70711-0.70711i
N = 9
k = 0, +1.00000+0.00000i
k = 1, +0.76604+0.64279i
k = 2, +0.17365+0.98481i
k = 3, -0.50000+0.86603i
k = 4, -0.93969+0.34202i
k = 5, -0.93969-0.34202i
k = 6, -0.50000-0.86603i
k = 7, +0.17365-0.98481i
k = 8, +0.76604-0.64279i
N = 10
k = 0, +1.00000+0.00000i
k = 1, +0.80902+0.58779i
k = 2, +0.30902+0.95106i
k = 3, -0.30902+0.95106i
k = 4, -0.80902+0.58779i
k = 5, -1.00000+0.00000i
k = 6, -0.80902-0.58779i
k = 7, -0.30902-0.95106i
k = 8, +0.30902-0.95106i
k = 9, +0.80902-0.58779i
```
## ALGOL 68
{{works with|ALGOL 68|Revision 1 - no extensions to language used}}
{{works with|ALGOL 68G|Any - tested with release [http://sourceforge.net/projects/algol68/files/algol68g/algol68g-1.18.0/algol68g-1.18.0-9h.tiny.el5.centos.fc11.i386.rpm/download 1.18.0-9h.tiny]}}
{{wont work with|ELLA ALGOL 68|Any (with appropriate job cards) - tested with release [http://sourceforge.net/projects/algol68/files/algol68toc/algol68toc-1.8.8d/algol68toc-1.8-8d.fc9.i386.rpm/download 1.8-8d] - due to extensive use of FORMATted transput}}
```algol68
FORMAT complex fmt=$g(-6,4)"⊥"g(-6,4)$;
FOR root FROM 2 TO 10 DO
printf(($g(4)$,root));
FOR n FROM 0 TO root-1 DO
printf(($xf(complex fmt)$,complex exp( 0 I 2*pi*n/root)))
OD;
printf($l$)
OD
```
Output:
```txt
+2 1.0000⊥0.0000 -1.000⊥0.0000
+3 1.0000⊥0.0000 -.5000⊥0.8660 -.5000⊥-.8660
+4 1.0000⊥0.0000 0.0000⊥1.0000 -1.000⊥0.0000 -.0000⊥-1.000
+5 1.0000⊥0.0000 0.3090⊥0.9511 -.8090⊥0.5878 -.8090⊥-.5878 0.3090⊥-.9511
+6 1.0000⊥0.0000 0.5000⊥0.8660 -.5000⊥0.8660 -1.000⊥0.0000 -.5000⊥-.8660 0.5000⊥-.8660
+7 1.0000⊥0.0000 0.6235⊥0.7818 -.2225⊥0.9749 -.9010⊥0.4339 -.9010⊥-.4339 -.2225⊥-.9749 0.6235⊥-.7818
+8 1.0000⊥0.0000 0.7071⊥0.7071 0.0000⊥1.0000 -.7071⊥0.7071 -1.000⊥0.0000 -.7071⊥-.7071 -.0000⊥-1.000 0.7071⊥-.7071
+9 1.0000⊥0.0000 0.7660⊥0.6428 0.1736⊥0.9848 -.5000⊥0.8660 -.9397⊥0.3420 -.9397⊥-.3420 -.5000⊥-.8660 0.1736⊥-.9848 0.7660⊥-.6428
+10 1.0000⊥0.0000 0.8090⊥0.5878 0.3090⊥0.9511 -.3090⊥0.9511 -.8090⊥0.5878 -1.000⊥0.0000 -.8090⊥-.5878 -.3090⊥-.9511 0.3090⊥-.9511 0.8090⊥-.5878
```
## AutoHotkey
ahk forum: [http://www.autohotkey.com/forum/post-276712.html#276712 discussion]
```AutoHotkey
n := 8, a := 8*atan(1)/n
Loop %n%
i := A_Index-1, t .= cos(a*i) ((s:=sin(a*i))<0 ? " - i*" . -s : " + i*" . s) "`n"
Msgbox % t
```
## AWK
```AWK
# syntax: GAWK -f ROOTS_OF_UNITY.AWK
BEGIN {
pi = 3.1415926
for (n=2; n<=5; n++) {
printf("%d: ",n)
for (root=0; root<=n-1; root++) {
real = cos(2 * pi * root / n)
imag = sin(2 * pi * root / n)
printf("%8.5f %8.5fi",real,imag)
if (root != n-1) { printf(", ") }
}
printf("\n")
}
exit(0)
}
```
{{out}}
```txt
2: 1.00000 0.00000i, -1.00000 0.00000i
3: 1.00000 0.00000i, -0.50000 0.86603i, -0.50000 -0.86603i
4: 1.00000 0.00000i, 0.00000 1.00000i, -1.00000 0.00000i, -0.00000 -1.00000i
5: 1.00000 0.00000i, 0.30902 0.95106i, -0.80902 0.58779i, -0.80902 -0.58779i, 0.30902 -0.95106i
```
## BASIC
{{works with|QuickBasic|4.5}}
{{trans|Java}}
For high n's, this may repeat the root of 1 + 0*i.
```qbasic
CLS
PI = 3.1415926#
n = 5 'this can be changed for any desired n
angle = 0 'start at angle 0
DO
real = COS(angle) 'real axis is the x axis
IF (ABS(real) < 10 ^ -5) THEN real = 0 'get rid of annoying sci notation
imag = SIN(angle) 'imaginary axis is the y axis
IF (ABS(imag) < 10 ^ -5) THEN imag = 0 'get rid of annoying sci notation
PRINT real; "+"; imag; "i" 'answer on every line
angle = angle + (2 * PI) / n
'all the way around the circle at even intervals
LOOP WHILE angle < 2 * PI
```
## BBC BASIC
```bbcbasic
@% = &20408
FOR n% = 2 TO 5
PRINT STR$(n%) ": " ;
FOR root% = 0 TO n%-1
real = COS(2*PI * root% / n%)
imag = SIN(2*PI * root% / n%)
PRINT real imag "i" ;
IF root% <> n%-1 PRINT "," ;
NEXT
PRINT
NEXT n%
```
'''Output:'''
```txt
2: 1.0000 0.0000i, -1.0000 0.0000i
3: 1.0000 0.0000i, -0.5000 0.8660i, -0.5000 -0.8660i
4: 1.0000 0.0000i, 0.0000 1.0000i, -1.0000 0.0000i, -0.0000 -1.0000i
5: 1.0000 0.0000i, 0.3090 0.9511i, -0.8090 0.5878i, -0.8090 -0.5878i, 0.3090 -0.9511i
```
## C
```c
#include
#include
int main()
{
double a, c, s, PI2 = atan2(1, 1) * 8;
int n, i;
for (n = 1; n < 10; n++) for (i = 0; i < n; i++) {
c = s = 0;
if (!i ) c = 1;
else if(n == 4 * i) s = 1;
else if(n == 2 * i) c = -1;
else if(3 * n == 4 * i) s = -1;
else
a = i * PI2 / n, c = cos(a), s = sin(a);
if (c) printf("%.2g", c);
printf(s == 1 ? "i" : s == -1 ? "-i" : s ? "%+.2gi" : "", s);
printf(i == n - 1 ?"\n":", ");
}
return 0;
}
```
## C#
```c#
using System;
using System.Collections.Generic;
using System.Linq;
using System.Numerics;
class Program
{
static IEnumerable RootsOfUnity(int degree)
{
return Enumerable
.Range(0, degree)
.Select(element => Complex.FromPolarCoordinates(1, 2 * Math.PI * element / degree));
}
static void Main()
{
var degree = 3;
foreach (var root in RootsOfUnity(degree))
{
Console.WriteLine(root);
}
}
}
```
Output:
```txt
(1, 0)
(-0,5, 0,866025403784439)
(-0,5, -0,866025403784438)
```
## C++
```cpp
#include
#include
#include
double const pi = 4 * std::atan(1);
int main()
{
for (int n = 2; n <= 10; ++n)
{
std::cout << n << ": ";
for (int k = 0; k < n; ++k)
std::cout << std::polar(1, 2*pi*k/n) << " ";
std::cout << std::endl;
}
}
```
## CoffeeScript
Most of the effort here is in formatting the results, and the output is still a bit clumsy.
```coffeescript
# Find the n nth-roots of 1
nth_roots_of_unity = (n) ->
(complex_unit_vector(2*Math.PI*i/n) for i in [1..n])
complex_unit_vector = (rad) ->
new Complex(Math.cos(rad), Math.sin(rad))
class Complex
constructor: (@real, @imag) ->
toString: ->
round_z = (n) ->
if Math.abs(n) < 0.00005 then 0 else n
fmt = (n) -> n.toFixed(3)
real = round_z @real
imag = round_z @imag
s = ''
if real and imag
"#{fmt real}+#{fmt imag}i"
else if real or !imag
"#{fmt real}"
else
"#{fmt imag}i"
do ->
for n in [2..5]
console.log "---1 to the 1/#{n}"
for root in nth_roots_of_unity n
console.log root.toString()
```
output
```txt
> coffee nth_roots.coffee
---1 to the 1/2
-1.000
1.000
---1 to the 1/3
-0.500+0.866i
-0.500+-0.866i
1.000
---1 to the 1/4
1.000i
-1.000
-1.000i
1.000
---1 to the 1/5
0.309+0.951i
-0.809+0.588i
-0.809+-0.588i
0.309+-0.951i
1.000
```
## Common Lisp
```lisp
(defun roots-of-unity (n)
(loop for i below n
collect (cis (* pi (/ (* 2 i) n)))))
```
The expression is slightly more complicated than necessary in order to preserve exact rational arithmetic until multiplying by pi. The author of this example is not a floating point expert and not sure whether this is actually useful; if not, the simpler expression is (cis (/ (* 2 pi i) n)).
## Crystal
{{trans|Ruby}}
```ruby
require "complex"
def roots_of_unity(n)
(0...n).map { |k| (2 * Math::PI * k / n).i.exp }
end
p roots_of_unity(3)
```
Or alternative
```ruby
def roots_of_unity(n)
(0...n).map { |k| Complex.new(Math.cos(2 * Math::PI * k / n), Math.sin(2 * Math::PI * k / n)) }
end
```
{{out}}
```txt
[(1+0.0i), (-0.4999999999999998+0.8660254037844387i), (-0.5000000000000004-0.8660254037844384i)]
```
## D
Using std.complex:
```d
import std.stdio, std.range, std.algorithm, std.complex;
import std.math: PI;
auto nthRoots(in int n) pure nothrow {
return n.iota.map!(k => expi(PI * 2 * (k + 1) / n));
}
void main() {
foreach (immutable i; 1 .. 6)
writefln("#%d: [%(%5.2f, %)]", i, i.nthRoots);
}
```
{{out}}
```txt
#1: [ 1.00+ 0.00i]
#2: [-1.00+-0.00i, 1.00+ 0.00i]
#3: [-0.50+ 0.87i, -0.50+-0.87i, 1.00+ 0.00i]
#4: [-0.00+ 1.00i, -1.00+-0.00i, 0.00+-1.00i, 1.00+ 0.00i]
#5: [ 0.31+ 0.95i, -0.81+ 0.59i, -0.81+-0.59i, 0.31+-0.95i, 1.00+ 0.00i]
```
## EchoLisp
```scheme
(define (roots-1 n)
(define theta (// (* 2 PI) n))
(for/list ((i n))
(polar 1. (* theta i))))
(roots-1 2)
→ (1+0i -1+0i)
(roots-1 3)
→ (1+0i -0.4999999999999998+0.8660254037844388i -0.5000000000000004-0.8660254037844384i)
(roots-1 4)
→ (1+0i 0+i -1+0i 0-i)
```
## ERRE
PROGRAM UNITY_ROOTS
!
! for rosettacode.org
!
BEGIN
PRINT(CHR$(12);) !CLS
N=5 ! this can be changed for any desired n
ANGLE=0 ! start at ANGLE 0
REPEAT
REAL=COS(ANGLE) ! real axis is the x axis
IF (ABS(REAL)<10^-5) THEN REAL=0 END IF ! get rid of annoying sci notation
IMAG=SIN(ANGLE) ! imaginary axis is the y axis
IF (ABS(IMAG)<10^-5) THEN IMAG=0 END IF ! get rid of annoying sci notation
PRINT(REAL;"+";IMAG;"i") ! answer on every line
ANGLE+=(2*π)/N
! all the way around the circle at even intervals
UNTIL ANGLE>=2*π
END PROGRAM
```
Note: Adapted from Qbasic version. π is the predefined constant Greek Pi.
## Forth
Complex numbers are not a native type in Forth, so we calculate the roots by hand.
```forth
: f0. ( f -- )
fdup 0e 0.001e f~ if fdrop 0e then f. ;
: .roots ( n -- )
dup 1 do
pi i 2* 0 d>f f* dup 0 d>f f/ ( F: radians )
fsincos cr ." real " f0. ." imag " f0.
loop drop ;
3 set-precision
5 .roots
```
{{libheader|Forth Scientific Library}}
On the other hand, complex numbers are implemented by the FSL.
{{works with|gforth|0.7.9_20170308}}
{{trans|C++}}
```forth
require fsl-util.fs
require fsl/complex.fs
: abs= 1E-12 F~ ;
: clamp-to-0 FDUP 0E0 abs= IF FDROP 0E0 THEN ;
: zclamp-to-0
clamp-to-0 FSWAP
clamp-to-0 FSWAP ;
: .roots
1+ 2 DO
I . ." : "
I 0 DO
1E0 2E0 PI F* I S>F F* J S>F F/ polar> zclamp-to-0 z. SPACE
LOOP
CR
LOOP ;
3 SET-PRECISION
5 .roots
```
## Fortran
### Sin/Cos + Scalar Loop
{{works with|Fortran|ISO Fortran 90 and later}}
```fortran
PROGRAM Roots
COMPLEX :: root
INTEGER :: i, n
REAL :: angle, pi
pi = 4.0 * ATAN(1.0)
DO n = 2, 7
angle = 0.0
WRITE(*,"(I1,A)", ADVANCE="NO") n,": "
DO i = 1, n
root = CMPLX(COS(angle), SIN(angle))
WRITE(*,"(SP,2F7.4,A)", ADVANCE="NO") root, "j "
angle = angle + (2.0*pi / REAL(n))
END DO
WRITE(*,*)
END DO
END PROGRAM Roots
```
Output
2: +1.0000+0.0000j -1.0000+0.0000j
3: +1.0000+0.0000j -0.5000+0.8660j -0.5000-0.8660j
4: +1.0000+0.0000j +0.0000+1.0000j -1.0000+0.0000j +0.0000-1.0000j
5: +1.0000+0.0000j +0.3090+0.9511j -0.8090+0.5878j -0.8090-0.5878j +0.3090-0.9511j
6: +1.0000+0.0000j +0.5000+0.8660j -0.5000+0.8660j -1.0000+0.0000j -0.5000-0.8660j +0.5000-0.8660j
7: +1.0000+0.0000j +0.6235+0.7818j -0.2225+0.9749j -0.9010+0.4339j -0.9010-0.4339j -0.2225-0.9749j +0.6235-0.7818j
===Exp + Array-valued Statement===
{{works with|Fortran|ISO Fortran 90 and later}}
```fortran
program unity
real, parameter :: pi = 3.141592653589793
complex, parameter :: i = (0, 1)
complex, dimension(0:7-1) :: unit_circle
integer :: n, j
do n = 2, 7
!!!! KEY STEP, does all the calculations in one statement !!!!
unit_circle(0:n-1) = exp(2*i*pi/n * (/ (j, j=0, n-1) /) )
write(*,"(i1,a)", advance="no") n, ": "
write(*,"(sp,2f7.4,a)", advance="no") (unit_circle(j), "j ", j = 0, n-1)
write(*,*)
end do
end program unity
```
## FunL
FunL has built-in support for complex numbers. i is predefined to represent the imaginary unit.
```funl
import math.{exp, Pi}
def rootsOfUnity( n ) = {exp( 2Pi i k/n ) | k <- 0:n}
println( rootsOfUnity(3) )
```
{{out}}
```txt
{1.0, -0.4999999999999998+0.8660254037844387i, -0.5000000000000004-0.8660254037844385i}
```
## FutureBasic
```futurebasic
include "ConsoleWindow"
dim as long n, root
dim as double real, imag
for n = 2 to 7
print n;":" ;
for root = 0 to n-1
real = cos( 2 * pi * root / n)
imag = sin( 2 * pi * root / n)
print using "-##.#####"; real;using "-##.#####"; imag; "i";
if root <> n-1 then print ",";
next
print
next
```
Output:
```txt
2: 1.00000 0.00000i, -1.00000 0.00000i
3: 1.00000 0.00000i, -0.50000 0.86603i, -0.50000 -0.86603i
4: 1.00000 0.00000i, 0.00000 1.00000i, -1.00000 0.00000i, -0.00000 -1.00000i
5: 1.00000 0.00000i, 0.30902 0.95106i, -0.80902 0.58779i, -0.80902 -0.58779i, 0.30902 -0.95106i
6: 1.00000 0.00000i, 0.50000 0.86603i, -0.50000 0.86603i, -1.00000 0.00000i, -0.50000 -0.86603i, 0.50000 -0.86603i
7: 1.00000 0.00000i, 0.62349 0.78183i, -0.22252 0.97493i, -0.90097 0.43388i, -0.90097 -0.43388i, -0.22252 -0.97493i, 0.62349 -0.78183i
```
## GAP
```gap
roots := n -> List([0 .. n-1], k -> E(n)^k);
r:=roots(7);
# [ 1, E(7), E(7)^2, E(7)^3, E(7)^4, E(7)^5, E(7)^6 ]
List(r, x -> x^7);
# [ 1, 1, 1, 1, 1, 1, 1 ]
```
## Go
```go
package main
import (
"fmt"
"math"
"math/cmplx"
)
func main() {
for n := 2; n <= 5; n++ {
fmt.Printf("%d roots of 1:\n", n)
for _, r := range roots(n) {
fmt.Printf(" %18.15f\n", r)
}
}
}
func roots(n int) []complex128 {
r := make([]complex128, n)
for i := 0; i < n; i++ {
r[i] = cmplx.Rect(1, 2*math.Pi*float64(i)/float64(n))
}
return r
}
```
Output:
```txt
2 roots of 1:
( 1.000000000000000+0.000000000000000i)
(-1.000000000000000+0.000000000000000i)
3 roots of 1:
( 1.000000000000000+0.000000000000000i)
(-0.500000000000000+0.866025403784439i)
(-0.500000000000000-0.866025403784438i)
4 roots of 1:
( 1.000000000000000+0.000000000000000i)
( 0.000000000000000+1.000000000000000i)
(-1.000000000000000+0.000000000000000i)
(-0.000000000000000-1.000000000000000i)
5 roots of 1:
( 1.000000000000000+0.000000000000000i)
( 0.309016994374948+0.951056516295154i)
(-0.809016994374947+0.587785252292473i)
(-0.809016994374947-0.587785252292473i)
( 0.309016994374947-0.951056516295154i)
```
## Groovy
Because the Groovy language does not provide a built-in facility for complex arithmetic, this example relies on the Complex class defined in the [[Complex_numbers#Groovy|Complex numbers]] example.
```groovy
/** The following closure creates a list of n evenly-spaced points around the unit circle,
* useful in FFT calculations, among other things */
def rootsOfUnity = { n ->
(0..
println "rootsOfUnity(${n}):"
def rou = rootsOfUnity(n)
rou.each { println it }
assert rou[0] == 1
def actual = n > 1 ? rou[Math.floor(n/2) as int] : rou[0]
def expected = n > 1 ? (n%2 == 0) ? -1 : ~rou[Math.ceil(n/2) as int] : rou[0]
def message = n > 1 ? (n%2 == 0) ? 'middle-most root should be -1' : 'two middle-most roots should be conjugates' : ''
assert (actual - expected).abs() < tol : message
assert rou.every { (it.rho - 1) < tol } : 'all roots should have magnitude 1'
println()
}
```
Output:
rootsOfUnity(1):
1.0
rootsOfUnity(2):
1.0
-1.0 + 1.2246467991473532E-16i
rootsOfUnity(3):
1.0
-0.4999999998186198 + 0.8660254038891585i
-0.5000000003627604 - 0.8660254035749988i
rootsOfUnity(4):
1.0
6.123233995736766E-17 + i
-1.0 + 1.2246467991473532E-16i
-1.8369701987210297E-16 - i
rootsOfUnity(5):
1.0
0.30901699437494745 + 0.9510565162951535i
-0.8090169943749473 + 0.5877852522924732i
-0.8090169943749475 - 0.587785252292473i
0.30901699437494723 - 0.9510565162951536i
rootsOfUnity(6):
1.0
0.4999999998186201 + 0.8660254038891584i
-0.5000000003627598 + 0.8660254035749991i
-1.0 - 6.283181638240517E-10i
-0.4999999992744804 - 0.8660254042033175i
0.5000000009068993 - 0.8660254032608401i
rootsOfUnity(16):
1.0
0.9238795325112867 + 0.3826834323650898i
0.7071067811865476 + 0.7071067811865475i
0.38268343236508984 + 0.9238795325112867i
6.123233995736766E-17 + i
-0.3826834323650897 + 0.9238795325112867i
-0.7071067811865475 + 0.7071067811865476i
-0.9238795325112867 + 0.3826834323650899i
-1.0 + 1.2246467991473532E-16i
-0.9238795325112868 - 0.38268343236508967i
-0.7071067811865477 - 0.7071067811865475i
-0.38268343236509034 - 0.9238795325112865i
-1.8369701987210297E-16 - i
0.38268343236509 - 0.9238795325112866i
0.7071067811865474 - 0.7071067811865477i
0.9238795325112865 - 0.3826834323650904i
```
## Haskell
```haskell
import Data.Complex (Complex, cis)
rootsOfUnity :: (Enum a, Floating a) => a -> [Complex a]
rootsOfUnity n =
[ cis (2 * pi * k / n)
| k <- [0 .. n - 1] ]
main :: IO ()
main = mapM_ print $ rootsOfUnity 3
```
{{Out}}
```haskell
1.0 :+ 0.0
(-0.4999999999999998) :+ 0.8660254037844388
(-0.5000000000000004) :+ (-0.8660254037844384)
```
=={{header|Icon}} and {{header|Unicon}}==
```icon
procedure main()
roots(10)
end
procedure roots(n)
every n := 2 to 10 do
every writes(n | (str_rep((0 to (n-1)) * 2 * &pi / n)) | "\n")
end
procedure str_rep(k)
return " " || cos(k) || "+" || sin(k) || "i"
end
```
Notes:
* The [[:Category:Icon_Programming_Library|The Icon Programming Library]] implements a complex type but not a polar type
## IDL
For some example n:
```idl
n = 5
print, exp( dcomplex( 0, 2*!dpi/n) ) ^ ( 1 + indgen(n) )
```
Outputs:
```idl
( 0.30901699, 0.95105652)( -0.80901699, 0.58778525)( -0.80901699, -0.58778525)( 0.30901699, -0.95105652)( 1.0000000, -1.1102230e-16)
```
## J
```j
rou=: [: ^ 0j2p1 * i. % ]
rou 4
1 0j1 _1 0j_1
rou 5
1 0.309017j0.951057 _0.809017j0.587785 _0.809017j_0.587785 0.309017j_0.951057
```
The computation can also be written as a loop, shown here for comparison only.
```j
rou1=: 3 : 0
z=. 0 $ r=. ^ o. 0j2 % y [ e=. 1
for. i.y do.
z=. z,e
e=. e*r
end.
z
)
```
## Java
Java doesn't have a nice way of dealing with complex numbers, so the real and imaginary parts are calculated separately based on the angle and printed together. There are also checks in this implementation to get rid of extremely small values (< 1.0E-3 where scientific notation sets in for Doubles). Instead, they are simply represented as 0. To remove those checks (for very high n's), remove both if statements.
```java
import java.util.Locale;
public class Test {
public static void main(String[] a) {
for (int n = 2; n < 6; n++)
unity(n);
}
public static void unity(int n) {
System.out.printf("%n%d: ", n);
//all the way around the circle at even intervals
for (double angle = 0; angle < 2 * Math.PI; angle += (2 * Math.PI) / n) {
double real = Math.cos(angle); //real axis is the x axis
if (Math.abs(real) < 1.0E-3)
real = 0.0; //get rid of annoying sci notation
double imag = Math.sin(angle); //imaginary axis is the y axis
if (Math.abs(imag) < 1.0E-3)
imag = 0.0;
System.out.printf(Locale.US, "(%9f,%9f) ", real, imag);
}
}
}
```
```txt
2: ( 1.000000, 0.000000) (-1.000000, 0.000000)
3: ( 1.000000, 0.000000) (-0.500000, 0.866025) (-0.500000,-0.866025)
4: ( 1.000000, 0.000000) ( 0.000000, 1.000000) (-1.000000, 0.000000) ( 0.000000,-1.000000)
5: ( 1.000000, 0.000000) ( 0.309017, 0.951057) (-0.809017, 0.587785) (-0.809017,-0.587785) ( 0.309017,-0.951057)
```
## JavaScript
```javascript
function Root(angle) {
with (Math) { this.r = cos(angle); this.i = sin(angle) }
}
Root.prototype.toFixed = function(p) {
return this.r.toFixed(p) + (this.i >= 0 ? '+' : '') + this.i.toFixed(p) + 'i'
}
function roots(n) {
var rs = [], teta = 2*Math.PI/n
for (var angle=0, i=0; i r.toString()
r == 0.0 -> i.toString() + 'i'
else -> "$r + ${i}i"
}
}
fun unity_roots(n: Number) = (1..n.toInt() - 1).map {
val a = it * 2 * PI / n.toDouble()
var r = cos(a); if (abs(r) < 1e-6) r = 0.0
var i = sin(a); if (abs(i) < 1e-6) i = 0.0
Complex(r, i)
}
fun main(args: Array) {
(1..4).forEach { println(listOf(1) + unity_roots(it)) }
println(listOf(1) + unity_roots(5.0))
}
```
{{out}}
```txt
[1]
[1, -1.0]
[1, -0.4999999999999998 + 0.8660254037844387i, -0.5000000000000004 + -0.8660254037844385i]
[1, 1.0i, -1.0, -1.0i]
[1, 0.30901699437494745 + 0.9510565162951535i, -0.8090169943749473 + 0.5877852522924732i, -0.8090169943749475 + -0.587785252292473i, 0.30901699437494723 + -0.9510565162951536i]
```
## Liberty BASIC
```lb
WindowWidth =400
WindowHeight =400
'nomainwin
open "N'th Roots of One" for graphics_nsb_nf as #w
#w "trapclose [quit]"
for n =1 To 10
angle =0
#w "font arial 16 bold"
print n; "th roots."
#w "cls"
#w "size 1 ; goto 200 200 ; down ; color lightgray ; circle 150 ; size 10 ; set 200 200 ; size 2"
#w "up ; goto 200 0 ; down ; goto 200 400 ; up ; goto 0 200 ; down ; goto 400 200"
#w "up ; goto 40 20 ; down ; color black"
#w "font arial 6"
#w "\"; n; " roots of 1."
for i = 1 To n
x = cos( Radian( angle))
y = sin( Radian( angle))
print using( "##", i); ": ( " + using( "##.######", x);_
" +i *" +using( "##.######", y); ") or e^( i *"; i -1; " *2 *Pi/ "; n; ")"
#w "color "; 255 *i /n; " 0 "; 256 -255 *i /n
#w "up ; goto 200 200"
#w "down ; goto "; 200 +150 *x; " "; 200 -150 *y
#w "up ; goto "; 200 +165 *x; " "; 200 -165 *y
#w "\"; str$( i)
#w "up"
angle =angle +360 /n
next i
timer 500, [on]
wait
[on]
timer 0
next n
wait
[quit]
close #w
end
function Radian( theta)
Radian =theta *3.1415926535 /180
end function
```
## Lua
Complex numbers from the Lua implementation on the complex numbers page.
```lua
--defines addition, subtraction, negation, multiplication, division, conjugation, norms, and a conversion to strgs.
complex = setmetatable({
__add = function(u, v) return complex(u.real + v.real, u.imag + v.imag) end,
__sub = function(u, v) return complex(u.real - v.real, u.imag - v.imag) end,
__mul = function(u, v) return complex(u.real * v.real - u.imag * v.imag, u.real * v.imag + u.imag * v.real) end,
__div = function(u, v) return u * complex(v.real / v.norm, -v.imag / v.norm) end,
__unm = function(u) return complex(-u.real, -u.imag) end,
__concat = function(u, v)
if type(u) == "table" then return u.real .. " + " .. u.imag .. "i" .. v
elseif type(u) == "string" or type(u) == "number" then return u .. v.real .. " + " .. v.imag .. "i"
end end,
__index = function(u, index)
local operations = {
norm = function(u) return u.real ^ 2 + u.imag ^ 2 end,
conj = function(u) return complex(u.real, -u.imag) end,
}
return operations[index] and operations[index](u)
end,
__newindex = function() error() end
}, {
__call = function(z, realpart, imagpart) return setmetatable({real = realpart, imag = imagpart}, complex) end
} )
n = io.read() + 0
val = complex(math.cos(2*math.pi / n), math.sin(2*math.pi / n))
root = complex(1, 0)
for i = 1, n do
root = root * val
print(root .. "")
end
```
## Maple
```Maple
RootsOfUnity := proc( n )
solve(z^n = 1, z);
end proc:
```
```Maple
for i from 2 to 6 do
printf( "%d: %a\n", i, [ RootsOfUnity(i) ] );
end do;
```
Output:
```Maple
2: [1, -1]
3: [1, -1/2-1/2*I*3^(1/2), -1/2+1/2*I*3^(1/2)]
4: [1, -1, I, -I]
5: [1, 1/4*5^(1/2)-1/4+1/4*I*2^(1/2)*(5+5^(1/2))^(1/2), -1/4*5^(1/2)-1/4+1/4*I*2^(1/2)*(5-5^(1/2))^(1/2), -1/4*5^(1/2)-1/4-1/4*I*2^(1/2)*(5-5^(1/2))^(1/2), 1/4*5^(1/2)-1/4-1/4*I*2^(1/2)*(5+5^(1/2))^(1/2)]
6: [1, -1, 1/2*(-2-2*I*3^(1/2))^(1/2), -1/2*(-2-2*I*3^(1/2))^(1/2), 1/2*(-2+2*I*3^(1/2))^(1/2), -1/2*(-2+2*I*3^(1/2))^(1/2)]
```
## Mathematica
Setting this up in Mathematica is easy, because it already handles complex numbers:
```Mathematica
RootsUnity[nthroot_Integer?Positive] := Table[Exp[2 Pi I i/nthroot], {i, 0, nthroot - 1}]
```
Note that Mathematica will keep the expression as exact as possible. Simplifications can be made to more known (trigonometric) functions by using the function ExpToTrig. If only a numerical approximation is necessary the function N will transform the exact result to a numerical approximation. Examples (exact not simplified, exact simplified, approximated):
```txt
RootsUnity[2]
RootsUnity[3]
RootsUnity[4]
RootsUnity[5]
RootsUnity[2]//ExpToTrig
RootsUnity[3]//ExpToTrig
RootsUnity[4]//ExpToTrig
RootsUnity[5]//ExpToTrig
RootsUnity[2]//N
RootsUnity[3]//N
RootsUnity[4]//N
RootsUnity[5]//N
```
gives back:
## MATLAB
```MATLAB
function z = rootsOfUnity(n)
assert(n >= 1,'n >= 1');
z = roots([1 zeros(1,n-1) -1]);
end
```
Sample Output:
```MATLAB>>
rootsOfUnity(3)
ans =
-0.500000000000000 + 0.866025403784439i
-0.500000000000000 - 0.866025403784439i
1.000000000000000
```
## Maxima
```maxima
solve(1 = x^n, x)
```
Demonstration:
```maxima
for n:1 thru 5 do display(solve(1 = x^n, x));
```
Output:
```maxima
solve(1 = x, x) = [x = 1]
solve(1 = x^2, x) = [x = -1, x = 1]
solve(1 = x^3, x) = [x = (sqrt(3)*%i-1)/2, x = -(sqrt(3)*%i+1)/2, x = 1]
solve(1 = x^4, x) = [x = %i, x = -1, x = -%i, x = 1]
solve(1 = x^5, x) = [x = %e^((2*%i*%pi)/5), x = %e^((4*%i*%pi)/5), x = %e^(-(4*%i*%pi)/5), x = %e^(-(2*%i*%pi)/5), x = 1]
```
## MiniScript
```MiniScript
complexRoots = function(n)
result = []
for i in range(0, n-1)
real = cos(2*pi * i/n)
if abs(real) < 1e-6 then real = 0
imag = sin(2*pi * i/n)
if abs(imag) < 1e-6 then imag = 0
result.push real + " " + "+" * (imag>=0) + imag + "i"
end for
return result
end function
for i in range(2,5)
print i + ": " + complexRoots(i).join(", ")
end for
```
{{out}}
```txt
2: 1 +0i, -1 +0i
3: 1 +0i, -0.5 +0.866025i, -0.5 -0.866025i
4: 1 +0i, 0 +1i, -1 +0i, 0 -1i
5: 1 +0i, 0.309017 +0.951057i, -0.809017 +0.587785i, -0.809017 -0.587785i, 0.309017 -0.951057i
```
=={{header|MK-61/52}}==
П0 0 П1 ИП1 sin ИП1 cos С/П 2 пи
* ИП0 / ИП1 + П1 БП 03
```
## Nim
{{trans|Python}}
```nim
import complex, math
proc rect(r, phi: float): Complex = (r * cos(phi), sin(phi))
proc croots(n): seq[Complex] =
result = @[]
if n <= 0: return
for k in 0 .. < n:
result.add rect(1, 2 * k.float * Pi / n.float)
for nr in 2..10:
echo nr, " ", croots(nr)
```
Output:
```txt
2 @[(1.0, 0.0), (-1.0, 1.224646799147353e-16)]
3 @[(1.0, 0.0), (-0.4999999999999998, 0.8660254037844387), (-0.5000000000000004, -0.8660254037844384)]
4 @[(1.0, 0.0), (6.123233995736766e-17, 1.0), (-1.0, 1.224646799147353e-16), (-1.83697019872103e-16, -1.0)]
5 @[(1.0, 0.0), (0.3090169943749475, 0.9510565162951535), (-0.8090169943749473, 0.5877852522924732), (-0.8090169943749476, -0.587785252292473), (0.3090169943749472, -0.9510565162951536)]
6 @[(1.0, 0.0), (0.5000000000000001, 0.8660254037844386), (-0.4999999999999998, 0.8660254037844387), (-1.0, 1.224646799147353e-16), (-0.5000000000000004, -0.8660254037844384), (0.5000000000000001, -0.8660254037844386)]
7 @[(1.0, 0.0), (0.6234898018587336, 0.7818314824680298), (-0.2225209339563143, 0.9749279121818236), (-0.900968867902419, 0.4338837391175582), (-0.9009688679024191, -0.433883739117558), (-0.2225209339563146, -0.9749279121818236), (0.6234898018587334, -0.7818314824680299)]
8 @[(1.0, 0.0), (0.7071067811865476, 0.7071067811865475), (6.123233995736766e-17, 1.0), (-0.7071067811865475, 0.7071067811865476), (-1.0, 1.224646799147353e-16), (-0.7071067811865477, -0.7071067811865475), (-1.83697019872103e-16, -1.0), (0.7071067811865474, -0.7071067811865477)]
9 @[(1.0, 0.0), (0.766044443118978, 0.6427876096865393), (0.1736481776669304, 0.984807753012208), (-0.4999999999999998, 0.8660254037844387), (-0.9396926207859083, 0.3420201433256689), (-0.9396926207859084, -0.3420201433256687), (-0.5000000000000004, -0.8660254037844384), (0.17364817766693, -0.9848077530122081), (0.7660444431189778, -0.6427876096865396)]
10 @[(1.0, 0.0), (0.8090169943749475, 0.5877852522924731), (0.3090169943749475, 0.9510565162951535), (-0.3090169943749473, 0.9510565162951536), (-0.8090169943749473, 0.5877852522924732), (-1.0, 1.224646799147353e-16), (-0.8090169943749476, -0.587785252292473), (-0.3090169943749476, -0.9510565162951535), (0.3090169943749472, -0.9510565162951536), (0.8090169943749473, -0.5877852522924734)]
```
## OCaml
```ocaml
open Complex
let pi = 4. *. atan 1.
let () =
for n = 1 to 10 do
Printf.printf "%2d " n;
for k = 1 to n do
let ret = polar 1. (2. *. pi *. float_of_int k /. float_of_int n) in
Printf.printf "(%f + %f i)" ret.re ret.im
done;
print_newline ()
done
```
## Octave
```octave
for j = 2 : 10
printf("*** %d\n", j);
for n = 1 : j
disp(exp(2i*pi*n/j));
endfor
disp("");
endfor
```
## OoRexx
{{trans|REXX}}
```oorexx
/*REXX program computes the K roots of unity (which include complex roots).*/
parse Version v
Say v
parse arg n frac . /*get optional arguments from the C.L. */
if n=='' then n=1 /*Not specified? Then use the default.*/
if frac='' then frac=5 /* " " " " " " */
start=abs(n) /*assume only one K is wanted. */
if n<0 then start=1 /*Negative? Then use a range of K's. */
/*display unity roots for a range, or */
do k=start to abs(n) /* just for one K. */
say right(k 'roots of unity',40,"-") /*display a pretty separator with title*/
do angle=0 by 360/k for k /*compute the angle for each root. */
rp=adjust(rxCalcCos(angle,,'D')) /*compute real part via COS function.*/
if left(rp,1)\=='-' then rp=" "rp /*not negative? Then pad with a blank.*/
ip=adjust(rxCalcSin(angle,,'D')) /*compute imaginary part via SIN funct.*/
if left(ip,1)\=='-' then ip="+"ip /*Not negative? Then pad with + char.*/
if ip=0 then say rp /*Only real part? Ignore imaginary part*/
else say left(rp,frac+4)ip'i' /*show the real & imaginary part*/
end /*angle*/
end /*k*/
exit /*stick a fork in it, we're all done. */
/*----------------------------------------------------------------------------*/
adjust: parse arg x; near0='1e-' || (digits()-digits()%10) /*compute small #*/
if abs(x)rexx nrootoo 5
REXX-ooRexx_4.2.0(MT)_64-bit 6.04 22 Feb 2014
------------------------5 roots of unity
1
0.30902 +0.95106i
-0.80902 +0.58779i
-0.80902 -0.58779i
0.30902 -0.95106i
```
## PARI/GP
```parigp
vector(n,k,exp(2*Pi*I*k/n))
```
sqrtn() can give the first n'th root, from which the others by multiplying or powering.
```parigp
nth_roots(n) = my(z);sqrtn(1,n,&z); vector(n,i, z^i);
```
Both the above give floating point complex numbers even when a root could be exact, like -1 or fourth root I.
quadgen() can be used for an exact 6th root. (Quads cannot be mixed with ordinary complex numbers, and they always print as w.)
```parigp
sixth_root = quadgen(-3); /* 6th root of unity, exact */
vector(6,n, sixth_root^n) /* all the 6'th roots */
```
## Pascal
{{trans|Fortran}}
```pascal
Program Roots;
var
root: record // poor man's complex type.
r: real;
i: real;
end;
i, n: integer;
angle: real;
begin
for n := 2 to 7 do
begin
angle := 0.0;
write(n, ': ');
for i := 1 to n do
begin
root.r := cos(angle);
root.i := sin(angle);
write(root.r:8:5, root.i:8:5, 'i ');
angle := angle + (2.0 * pi / n);
end;
writeln;
end;
end.
```
Output:
```txt
2: 1.00000 0.00000i -1.00000 0.00000i
3: 1.00000 0.00000i -0.50000 0.86603i -0.50000-0.86603i
4: 1.00000 0.00000i 0.00000 1.00000i -1.00000 0.00000i -0.00000-1.00000i
5: 1.00000 0.00000i 0.30902 0.95106i -0.80902 0.58779i -0.80902-0.58779i 0.30902-0.95106i
6: 1.00000 0.00000i 0.50000 0.86603i -0.50000 0.86603i -1.00000-0.00000i -0.50000-0.86603i 0.50000-0.86603i
7: 1.00000 0.00000i 0.62349 0.78183i -0.22252 0.97493i -0.90097 0.43388i -0.90097-0.43388i -0.22252-0.97493i 0.62349-0.78183i
```
## Perl
{{works with|Perl|5.6.0}}
{{libheader|Math::Complex}}
The root() function returns a list of the N many N'th roots of any complex Z, in this case 1.
```perl
use Math::Complex;
foreach my $n (2 .. 10) {
printf "%2d", $n;
my @roots = root(1,$n);
foreach my $root (@roots) {
$root->display_format(style => 'cartesian', format => '%.3f');
print " $root";
}
print "\n";
}
```
Output:
```txt
2 1.000 -1.000+0.000i
3 1.000 -0.500+0.866i -0.500-0.866i
4 1.000 0.000+1.000i -1.000+0.000i -0.000-1.000i
5 1.000 0.309+0.951i -0.809+0.588i -0.809-0.588i 0.309-0.951i
6 1.000 0.500+0.866i -0.500+0.866i -1.000+0.000i -0.500-0.866i 0.500-0.866i
7 1.000 0.623+0.782i -0.223+0.975i -0.901+0.434i -0.901-0.434i -0.223-0.975i 0.623-0.782i
8 1.000 0.707+0.707i 0.000+1.000i -0.707+0.707i -1.000+0.000i -0.707-0.707i -0.000-1.000i 0.707-0.707i
9 1.000 0.766+0.643i 0.174+0.985i -0.500+0.866i -0.940+0.342i -0.940-0.342i -0.500-0.866i 0.174-0.985i 0.766-0.643i
10 1.000 0.809+0.588i 0.309+0.951i -0.309+0.951i -0.809+0.588i -1.000+0.000i -0.809-0.588i -0.309-0.951i 0.309-0.951i 0.809-0.588i
```
## Perl 6
Perl 6 has a built-in function cis which returns a unitary complex number given its phase. Perl 6 also defines the tau = 2*pi constant. Thus the k-th n-root of unity can simply be written cis(k*τ/n).
```perl6
constant n = 10;
for ^n -> \k {
say cis(k*τ/n);
}
```
{{out}}
```txt
1+0i
0.809016994374947+0.587785252292473i
0.309016994374947+0.951056516295154i
-0.309016994374947+0.951056516295154i
-0.809016994374947+0.587785252292473i
-1+1.22464679914735e-16i
-0.809016994374948-0.587785252292473i
-0.309016994374948-0.951056516295154i
0.309016994374947-0.951056516295154i
0.809016994374947-0.587785252292473i
```
## Phix
{{trans|AWK}}
```Phix
for n=2 to 10 do
printf(1,"%2d:",n)
for root=0 to n-1 do
atom real = cos(2*PI*root/n)
atom imag = sin(2*PI*root/n)
printf(1,"%s %6.3f %6.3fi",{iff(root?",":""),real,imag})
end for
printf(1,"\n")
end for
```
2: 1.000 0.000i, -1.000 0.000i
3: 1.000 0.000i, -0.500 0.866i, -0.500 -0.866i
4: 1.000 0.000i, 0.000 1.000i, -1.000 0.000i, -0.000 -1.000i
5: 1.000 0.000i, 0.309 0.951i, -0.809 0.588i, -0.809 -0.588i, 0.309 -0.951i
6: 1.000 0.000i, 0.500 0.866i, -0.500 0.866i, -1.000 0.000i, -0.500 -0.866i, 0.500 -0.866i
7: 1.000 0.000i, 0.623 0.782i, -0.223 0.975i, -0.901 0.434i, -0.901 -0.434i, -0.223 -0.975i, 0.623 -0.782i
8: 1.000 0.000i, 0.707 0.707i, 0.000 1.000i, -0.707 0.707i, -1.000 0.000i, -0.707 -0.707i, -0.000 -1.000i, 0.707 -0.707i
9: 1.000 0.000i, 0.766 0.643i, 0.174 0.985i, -0.500 0.866i, -0.940 0.342i, -0.940 -0.342i, -0.500 -0.866i, 0.174 -0.985i, 0.766 -0.643i
10: 1.000 0.000i, 0.809 0.588i, 0.309 0.951i, -0.309 0.951i, -0.809 0.588i, -1.000 0.000i, -0.809 -0.588i, -0.309 -0.951i, 0.309 -0.951i, 0.809 -0.588i
```
## PL/I
```PL/I
complex_roots:
procedure (N);
declare N fixed binary nonassignable;
declare x float, c fixed decimal (10,8) complex;
declare twopi float initial ((4*asin(1.0)));
do x = 0 to twopi by twopi/N;
c = complex(cos(x), sin(x));
put skip list (c);
end;
end complex_roots;
1.00000000+0.00000000I
0.80901700+0.58778524I
0.30901697+0.95105654I
-0.30901703+0.95105648I
-0.80901706+0.58778518I
-1.00000000-0.00000008I
-0.80901694-0.58778536I
-0.30901709-0.95105648I
0.30901712-0.95105648I
0.80901724-0.58778494I
```
## PicoLisp
{{trans|C}}
```PicoLisp
(load "@lib/math.l")
(for N (range 2 10)
(let Angle 0.0
(prin N ": ")
(for I N
(let Ipart (sin Angle)
(prin
(round (cos Angle) 4)
(if (lt0 Ipart) "-" "+")
"j"
(round (abs Ipart) 4)
" " ) )
(inc 'Angle (*/ 2 pi N)) )
(prinl) ) )
```
## PureBasic
```Purebasic
OpenConsole()
For n = 2 To 10
angle = 0
PrintN(Str(n))
For i = 1 To n
x.f = Cos(Radian(angle))
y.f = Sin(Radian(angle))
PrintN( Str(i) + ": " + StrF(x, 6) + " / " + StrF(y, 6))
angle = angle + (360 / n)
Next
Next
Input()
```
## Python
{{works with|Python|3.7}}
```python
import cmath
class Complex(complex):
def __repr__(self):
rp = '%7.5f' % self.real if not self.pureImag() else ''
ip = '%7.5fj' % self.imag if not self.pureReal() else ''
conj = '' if (
self.pureImag() or self.pureReal() or self.imag < 0.0
) else '+'
return '0.0' if (
self.pureImag() and self.pureReal()
) else rp + conj + ip
def pureImag(self):
return abs(self.real) < 0.000005
def pureReal(self):
return abs(self.imag) < 0.000005
def croots(n):
if n <= 0:
return None
return (Complex(cmath.rect(1, 2 * k * cmath.pi / n)) for k in range(n))
# in pre-Python 2.6:
# return (Complex(cmath.exp(2j*k*cmath.pi/n)) for k in range(n))
for nr in range(2, 11):
print(nr, list(croots(nr)))
```
{{Out}}
```txt
2 [1.00000, -1.00000]
3 [1.00000, -0.50000+0.86603j, -0.50000-0.86603j]
4 [1.00000, 1.00000j, -1.00000, -1.00000j]
5 [1.00000, 0.30902+0.95106j, -0.80902+0.58779j, -0.80902-0.58779j, 0.30902-0.95106j]
6 [1.00000, 0.50000+0.86603j, -0.50000+0.86603j, -1.00000, -0.50000-0.86603j, 0.50000-0.86603j]
7 [1.00000, 0.62349+0.78183j, -0.22252+0.97493j, -0.90097+0.43388j, -0.90097-0.43388j, -0.22252-0.97493j, 0.62349-0.78183j]
8 [1.00000, 0.70711+0.70711j, 1.00000j, -0.70711+0.70711j, -1.00000, -0.70711-0.70711j, -1.00000j, 0.70711-0.70711j]
9 [1.00000, 0.76604+0.64279j, 0.17365+0.98481j, -0.50000+0.86603j, -0.93969+0.34202j, -0.93969-0.34202j, -0.50000-0.86603j, 0.17365-0.98481j, 0.76604-0.64279j]
10 [1.00000, 0.80902+0.58779j, 0.30902+0.95106j, -0.30902+0.95106j, -0.80902+0.58779j, -1.00000, -0.80902-0.58779j, -0.30902-0.95106j, 0.30902-0.95106j, 0.80902-0.58779j]
```
## R
```R
for(j in 2:10) {
r <- sprintf("%d: ", j)
for(n in 1:j) {
r <- paste(r, format(exp(2i*pi*n/j), digits=4), ifelse(n (for ([r (roots-of-unity 3)]) (displayln r))
1
-0.4999999999999998+0.8660254037844388i
-0.5000000000000004-0.8660254037844384i
```
## REXX
REXX doesn't have complex arithmetic, so the (real) values of '''cos''' and '''sin''' of multiples of 2 pi radians (divided by K) are used.
Also, REXX doesn't have the '''pi''' constant defined, nor a '''sin''' or '''cos''' function, so they are included below within the REXX program.
Note: this REXX version only ''displays'' '''5''' significant digits past the decimal point, but this can be overridden by specifying the 2nd argument when invoking the REXX program.
(See the value of the REXX variable '''frac''', 4th line).
```rexx
/*REXX program computes the K roots of unity (which usually includes complex roots).*/
parse arg n frac . /*get optional arguments from the C.L. */
if n=='' | n=="," then n= 1 /*Not specified? Then use the default.*/
if frac='' | frac=="," then frac= 5 /* " " " " " " */
start= abs(n) /*assume only one K is wanted. */
if n<0 then start= 1 /*Negative? Then use a range of K's. */
numeric digits length( pi() ) - 1 /*use number of decimal digits in pi. */
pi2= pi + pi /*obtain the value of pi doubled. */
/*display unity roots for a range, or */
do #=start to abs(n) /* just for one K. */
say right(# 'roots of unity', 40, "─") ' (showing' frac "fractional decimal digits)"
do angle=0 by pi2/# for # /*compute the angle for each root. */
rp= adjust( cos(angle) ) /*compute real part via COS function.*/
if left(rp, 1) \== '-' then rp=" "rp /*not negative? Then pad with a blank.*/
ip= adjust( sin(angle) ) /*compute imaginary part via SIN funct.*/
if left(ip, 1) \== '-' then ip="+"ip /*Not negative? Then pad with + char.*/
if ip=0 then say rp /*Only real part? Ignore imaginary part*/
else say left(rp, frac+4)ip'i' /*display the real and imaginary part. */
end /*angle*/
end /*#*/
exit /*stick a fork in it, we're all done. */
/*──────────────────────────────────────────────────────────────────────────────────────*/
pi: pi=3.141592653589793238462643383279502884197169399375105820974944592307816; return pi
r2r: return arg(1) // ( pi() * 2 ) /*reduce #radians: -2pi──► +2pi radians*/
/*──────────────────────────────────────────────────────────────────────────────────────*/
adjust: parse arg x; near0= '1e-' || (digits() - digits() % 10) /*compute a tiny number.*/
if abs(x) < near0 then x= 0 /*if it's near zero, then assume zero.*/
return format(x, , frac) / 1 /*fraction digits past decimal point. */
/*──────────────────────────────────────────────────────────────────────────────────────*/
cos: procedure; parse arg x; x= r2r(x); a= abs(x); numeric fuzz min(9, digits()-9)
if a=pi/3 then return .5; if a=pi/2|a=pi*2 then return 0
if a=pi then return -1; if a=pi*2/3 then return -.5; z=1; _=1; $x= x * x
do k=2 by 2 until p=z; p=z; _= - _*$x / (k*(k-1)); z= z+ _; end; return z
/*──────────────────────────────────────────────────────────────────────────────────────*/
sin: procedure; parse arg x; x= r2r(x); numeric fuzz min(5, digits()-3)
if abs(x)=pi then return 0; z= x; _=x; $x= x * x
do k=2 by 2 until p=z; p=z; _= - _*$x / (k*(k+1)); z= z+ _; end; return z
```
{{out|output|text= when using the input of: 5 }}
```txt
────────────────────────5 roots of unity (showing 5 fractional decimal digits)
1
0.30902 +0.95106i
-0.80902 +0.58779i
-0.80902 -0.58779i
0.30902 -0.95106i
```
{{out|output|text= when using the input of: 10 36 }}
```txt
───────────────────────10 roots of unity (showing 36 fractional decimal digits)
1
0.809016994374947424102293417182819059 +0.587785252292473129168705954639072769i
0.309016994374947424102293417182819059 +0.951056516295153572116439333379382143i
-0.309016994374947424102293417182819059 +0.951056516295153572116439333379382143i
-0.809016994374947424102293417182819059 +0.587785252292473129168705954639072769i
-1
-0.809016994374947424102293417182819059 -0.587785252292473129168705954639072769i
-0.309016994374947424102293417182819059 -0.951056516295153572116439333379382143i
0.309016994374947424102293417182819059 -0.951056516295153572116439333379382143i
0.809016994374947424102293417182819059 -0.587785252292473129168705954639072769i
```
{{out|output|text= when using the input of: -12 }}
(Shown at five-sixths size.)
────────────────────────1 roots of unity (showing 5 fractional decimal digits)
1
────────────────────────2 roots of unity (showing 5 fractional decimal digits)
1
-1
────────────────────────3 roots of unity (showing 5 fractional decimal digits)
1
-0.5 +0.86603i
-0.5 -0.86603i
────────────────────────4 roots of unity (showing 5 fractional decimal digits)
1
0 +1i
-1
0 -1i
────────────────────────5 roots of unity (showing 5 fractional decimal digits)
1
0.30902 +0.95106i
-0.80902 +0.58779i
-0.80902 -0.58779i
0.30902 -0.95106i
────────────────────────6 roots of unity (showing 5 fractional decimal digits)
1
0.5 +0.86603i
-0.5 +0.86603i
-1
-0.5 -0.86603i
0.5 -0.86603i
────────────────────────7 roots of unity (showing 5 fractional decimal digits)
1
0.62349 +0.78183i
-0.22252 +0.97493i
-0.90097 +0.43388i
-0.90097 -0.43388i
-0.22252 -0.97493i
0.62349 -0.78183i
────────────────────────8 roots of unity (showing 5 fractional decimal digits)
1
0.70711 +0.70711i
0 +1i
-0.70711 +0.70711i
-1
-0.70711 -0.70711i
0 -1i
0.70711 -0.70711i
────────────────────────9 roots of unity (showing 5 fractional decimal digits)
1
0.76604 +0.64279i
0.17365 +0.98481i
-0.5 +0.86603i
-0.93969 +0.34202i
-0.93969 -0.34202i
-0.5 -0.86603i
0.17365 -0.98481i
0.76604 -0.64279i
───────────────────────10 roots of unity (showing 5 fractional decimal digits)
1
0.80902 +0.58779i
0.30902 +0.95106i
-0.30902 +0.95106i
-0.80902 +0.58779i
-1
-0.80902 -0.58779i
-0.30902 -0.95106i
0.30902 -0.95106i
0.80902 -0.58779i
───────────────────────11 roots of unity (showing 5 fractional decimal digits)
1
0.84125 +0.54064i
0.41542 +0.90963i
-0.14231 +0.98982i
-0.65486 +0.75575i
-0.95949 +0.28173i
-0.95949 -0.28173i
-0.65486 -0.75575i
-0.14231 -0.98982i
0.41542 -0.90963i
0.84125 -0.54064i
───────────────────────12 roots of unity (showing 5 fractional decimal digits)
1
0.86603 +0.5i
0.5 +0.86603i
0 +1i
-0.5 +0.86603i
-0.86603 +0.5i
-1
-0.86603 -0.5i
-0.5 -0.86603i
0 -1i
0.5 -0.86603i
0.86603 -0.5i
```
## Ring
```ring
decimals(4)
for n = 2 to 5
see string(n) + " : "
for root = 0 to n-1
real = cos(2*3.14 * root / n)
imag = sin(2*3.14 * root / n)
see "" + real + " " + imag + "i"
if root != n-1 see ", " ok
next
see nl
next
```
## RLaB
RLaB can find the n-roots of unity by solving the polynomial equation
:
It uses the solver ''polyroots''. Interested user is recommended to check the rlabplus manual for details on the solver and the parameters that tune the solver performance.
```RLaB
// specify polynomial
>> n = 10;
>> a = zeros(1,n+1); a[1] = 1; a[n+1] = -1;
>> polyroots(a)
radius roots success
>> polyroots(a).roots
-0.309016994 + 0.951056516i
-0.809016994 + 0.587785252i
-1 + 5.95570041e-23i
-0.809016994 - 0.587785252i
-0.309016994 - 0.951056516i
0.309016994 - 0.951056516i
0.809016994 - 0.587785252i
1 + 0i
0.809016994 + 0.587785252i
0.309016994 + 0.951056516i
```
## Ruby
```ruby
def roots_of_unity(n)
(0...n).map {|k| Complex.polar(1, 2 * Math::PI * k / n)}
end
p roots_of_unity(3)
```
{{out}}
```txt
[(1+0.0i), (-0.4999999999999998+0.8660254037844387i), (-0.5000000000000004-0.8660254037844384i)]
```
## Run BASIC
```runbasic
PI = 3.1415926535
FOR n = 2 TO 5
PRINT n;":" ;
FOR root = 0 TO n-1
real = COS(2*PI * root / n)
imag = SIN(2*PI * root / n)
PRINT using("-##.#####",real);using("-##.#####",imag);"i";
IF root <> n-1 then PRINT "," ;
NEXT
PRINT
NEXT
```
Output:
```txt
2: 1.00000 0.00000i, -1.00000 0.00000i
3: 1.00000 0.00000i, -0.50000 0.86603i, -0.50000 -0.86603i
4: 1.00000 0.00000i, 0.00000 1.00000i, -1.00000 0.00000i, 0.00000 -1.00000i
5: 1.00000 0.00000i, 0.30902 0.95106i, -0.80902 0.58779i, -0.80902 -0.58779i, 0.30902 -0.95106i
```
## Rust
Here we demonstrate initialization from polar complex coordinate, radius 1, e^πi/n, and raising the resulting complex number to the power 2k for k in 0..n-1, which generates approximate roots (see the Mathematica answer for a nice display of exact vs approximate). This code will require adding the num crate to one's rust project, typically in Cargo.toml [dependencies] \n num="0.2.0";
```C
use num::Complex;
fn main() {
let n = 8;
let z = Complex::from_polar(&1.0,&(1.0*std::f64::consts::PI/n as f64));
for k in 0..=n-1 {
println!("e^{:2}πi/{} ≈ {:>14.3}",2*k,n,z.powf(2.0*k as f64));
}
}
```
```txt
e^ 0πi/8 ≈ 1.000+0.000i
e^ 2πi/8 ≈ 0.707+0.707i
e^ 4πi/8 ≈ 0.000+1.000i
e^ 6πi/8 ≈ -0.707+0.707i
e^ 8πi/8 ≈ -1.000+0.000i
e^10πi/8 ≈ -0.707-0.707i
e^12πi/8 ≈ -0.000-1.000i
e^14πi/8 ≈ 0.707-0.707i
```
## Scala
Using [[Arithmetic/Complex#Scala|Complex]] class from task Arithmetic/Complex.
```scala
def rootsOfUnity(n:Int)=for(k <- 0 until n) yield Complex.fromPolar(1.0, 2*math.Pi*k/n)
```
Usage:
```txt
rootsOfUnity(3) foreach println
1.0+0.0i
-0.4999999999999998+0.8660254037844387i
-0.5000000000000004-0.8660254037844385i
```
## Seed7
```seed7
$ include "seed7_05.s7i";
include "float.s7i";
include "complex.s7i";
const proc: main is func
local
var integer: n is 0;
var integer: k is 0;
begin
for n range 2 to 10 do
write(n lpad 2 <& ": ");
for k range 0 to pred(n) do
write(polar(1.0, 2.0 * PI * flt(k) / flt(n)) digits 4 lpad 15 <& " ");
end for;
writeln;
end for;
end func;
```
Output:
```seed7
2: 1.0000+0.0000i -1.0000+0.0000i
3: 1.0000+0.0000i -0.5000+0.8660i -0.5000-0.8660i
4: 1.0000+0.0000i 0.0000+1.0000i -1.0000+0.0000i 0.0000-1.0000i
5: 1.0000+0.0000i 0.3090+0.9511i -0.8090+0.5878i -0.8090-0.5878i 0.3090-0.9511i
6: 1.0000+0.0000i 0.5000+0.8660i -0.5000+0.8660i -1.0000+0.0000i -0.5000-0.8660i 0.5000-0.8660i
7: 1.0000+0.0000i 0.6235+0.7818i -0.2225+0.9749i -0.9010+0.4339i -0.9010-0.4339i -0.2225-0.9749i 0.6235-0.7818i
8: 1.0000+0.0000i 0.7071+0.7071i 0.0000+1.0000i -0.7071+0.7071i -1.0000+0.0000i -0.7071-0.7071i 0.0000-1.0000i 0.7071-0.7071i
9: 1.0000+0.0000i 0.7660+0.6428i 0.1736+0.9848i -0.5000+0.8660i -0.9397+0.3420i -0.9397-0.3420i -0.5000-0.8660i 0.1736-0.9848i 0.7660-0.6428i
10: 1.0000+0.0000i 0.8090+0.5878i 0.3090+0.9511i -0.3090+0.9511i -0.8090+0.5878i -1.0000+0.0000i -0.8090-0.5878i -0.3090-0.9511i 0.3090-0.9511i 0.8090-0.5878i
```
## Scheme
```scheme
(define pi (* 4 (atan 1)))
(do ((n 2 (+ n 1)))
((> n 10))
(display n)
(do ((k 0 (+ k 1)))
((>= k n))
(display " ")
(display (make-polar 1 (* 2 pi (/ k n)))))
(newline))
```
## Sidef
{{trans|Perl 6}}
```ruby
func roots_of_unity(n) {
n.of { |j|
exp(2i * Num.pi / n * j)
}
}
roots_of_unity(5).each { |c|
printf("%+.5f%+.5fi\n", c.reals)
}
```
{{out}}
```txt
+1.00000+0.00000i
+0.30902+0.95106i
-0.80902+0.58779i
-0.80902-0.58779i
+0.30902-0.95106i
```
## Sparkling
```sparkling
function unity_roots(n) {
// nth-root(1) = cos(2 * k * pi / n) + i * sin(2 * k * pi / n)
return map(range(n), function(idx, k) {
return {
"re": cos(2 * k * M_PI / n),
"im": sin(2 * k * M_PI / n)
};
});
}
// pirnt 6th roots of unity
foreach(unity_roots(6), function(k, v) {
printf("%.3f%+.3fi\n", v.re, v.im);
});
```
## Stata
```stata
n=7
exp(2i*pi()/n*(0::n-1))
1
+-----------------------------+
1 | 1 |
2 | .623489802 + .781831482i |
3 | -.222520934 + .974927912i |
4 | -.900968868 + .433883739i |
5 | -.900968868 - .433883739i |
6 | -.222520934 - .974927912i |
7 | .623489802 - .781831482i |
+-----------------------------+
```
## Tcl
```Tcl
package require Tcl 8.5
namespace import tcl::mathfunc::*
set pi 3.14159265
for {set n 2} {$n <= 10} {incr n} {
set angle 0.0
set row $n:
for {set i 1} {$i <= $n} {incr i} {
lappend row [format %5.4f%+5.4fi [cos $angle] [sin $angle]]
set angle [expr {$angle + 2*$pi/$n}]
}
puts $row
}
```
=={{header|TI-89 BASIC}}==
```ti89b
cZeros(x^n - 1, x)
```
For n=3 in exact mode, the results are
```ti89b
{-1/2+√(3)/2*i, -1/2-√(3)/2*i, 1}
```
## Ursala
The roots function takes a number n to the nth root of -1, squares it, and iteratively makes a list of its first n powers (oblivious to roundoff error). Complex functions cpow and mul are used, which are called from the host system's standard C library.
```Ursala
#import std
#import nat
#import flo
roots = ~&htxPC+ c..mul:-0^*DlSiiDlStK9\iota c..mul@iiX+ c..cpow/-1.+ div/1.+ float
#cast %jLL
tests = roots* <1,2,3,4,5,6>
```
The output is a list of lists of complex numbers.
```txt
<
<1.000e+00-2.449e-16j>,
<
1.000e+00-2.449e-16j,
-1.000e+00+1.225e-16j>,
<
1.000e+00-8.327e-16j,
-5.000e-01+8.660e-01j,
-5.000e-01-8.660e-01j>,
<
1.000e+00-8.882e-16j,
2.220e-16+1.000e+00j,
-1.000e+00+4.441e-16j,
-6.661e-16-1.000e+00j>,
<
1.000e+00-5.551e-17j,
3.090e-01+9.511e-01j,
-8.090e-01+5.878e-01j,
-8.090e-01-5.878e-01j,
3.090e-01-9.511e-01j>,
<
1.000e+00-1.221e-15j,
5.000e-01+8.660e-01j,
-5.000e-01+8.660e-01j,
-1.000e+00+6.106e-16j,
-5.000e-01-8.660e-01j,
5.000e-01-8.660e-01j>>
```
## VBA
```vb
Public Sub roots_of_unity()
For n = 2 To 9
Debug.Print n; "th roots of 1:"
For r00t = 0 To n - 1
Debug.Print " Root "; r00t & ": "; WorksheetFunction.Complex(Cos(2 * WorksheetFunction.Pi() * r00t / n), _
Sin(2 * WorksheetFunction.Pi() * r00t / n))
Next r00t
Debug.Print
Next n
End Sub
```
{{out}}
```txt
2 th roots of 1:
Root 0: 1
Root 1: -1+1.22460635382238E-16i
3 th roots of 1:
Root 0: 1
Root 1: -0.5+0.866025403784439i
Root 2: -0.5-0.866025403784438i
4 th roots of 1:
Root 0: 1
Root 1: 6.12303176911189E-17+i
Root 2: -1+1.22460635382238E-16i
Root 3: -1.83690953073357E-16-i
5 th roots of 1:
Root 0: 1
Root 1: 0.309016994374947+0.951056516295154i
Root 2: -0.809016994374947+0.587785252292473i
Root 3: -0.809016994374948-0.587785252292473i
Root 4: 0.309016994374947-0.951056516295154i
6 th roots of 1:
Root 0: 1
Root 1: 0.5+0.866025403784439i
Root 2: -0.5+0.866025403784439i
Root 3: -1+1.22460635382238E-16i
Root 4: -0.5-0.866025403784438i
Root 5: 0.5-0.866025403784439i
7 th roots of 1:
Root 0: 1
Root 1: 0.623489801858734+0.78183148246803i
Root 2: -0.222520933956314+0.974927912181824i
Root 3: -0.900968867902419+0.433883739117558i
Root 4: -0.900968867902419-0.433883739117558i
Root 5: -0.222520933956315-0.974927912181824i
Root 6: 0.623489801858733-0.78183148246803i
8 th roots of 1:
Root 0: 1
Root 1: 0.707106781186548+0.707106781186547i
Root 2: 6.12303176911189E-17+i
Root 3: -0.707106781186547+0.707106781186548i
Root 4: -1+1.22460635382238E-16i
Root 5: -0.707106781186548-0.707106781186547i
Root 6: -1.83690953073357E-16-i
Root 7: 0.707106781186547-0.707106781186548i
9 th roots of 1:
Root 0: 1
Root 1: 0.766044443118978+0.642787609686539i
Root 2: 0.17364817766693+0.984807753012208i
Root 3: -0.5+0.866025403784439i
Root 4: -0.939692620785908+0.342020143325669i
Root 5: -0.939692620785908-0.342020143325669i
Root 6: -0.5-0.866025403784438i
Root 7: 0.17364817766693-0.984807753012208i
Root 8: 0.766044443118978-0.64278760968654i
```
## zkl
{{trans|C}}
```zkl
PI2:=(0.0).pi*2;
foreach n,i in ([1..9],n){
c:=s:=0;
if(not i) c = 1;
else if(n==4*i) s = 1;
else if(n==2*i) c = -1;
else if(3*n==4*i) s = -1;
else a,c,s:=PI2*i/n,a.cos(),a.sin();
if(c) print("%.2g".fmt(c));
print( (s==1 and "i") or (s==-1 and "-i" or (s and "%+.2gi" or"")).fmt(s));
print( (i==n-1) and "\n" or ", ");
}
```
{{out}}
```txt
1
1, -1
1, -0.5+0.87i, -0.5-0.87i
1, i, -1, -i
1, 0.31+0.95i, -0.81+0.59i, -0.81-0.59i, 0.31-0.95i
1, 0.5+0.87i, -0.5+0.87i, -1, -0.5-0.87i, 0.5-0.87i
1, 0.62+0.78i, -0.22+0.97i, -0.9+0.43i, -0.9-0.43i, -0.22-0.97i, 0.62-0.78i
1, 0.71+0.71i, i, -0.71+0.71i, -1, -0.71-0.71i, -i, 0.71-0.71i
1, 0.77+0.64i, 0.17+0.98i, -0.5+0.87i, -0.94+0.34i, -0.94-0.34i, -0.5-0.87i, 0.17-0.98i, 0.77-0.64i
```