// Written in the D programming language.
/** This module contains the $(LREF Complex) type, which is used to represent
complex numbers, along with related mathematical operations and functions.
$(LREF Complex) will eventually
$(DDLINK deprecate, Deprecated Features, replace)
the built-in types `cfloat`, `cdouble`, `creal`, `ifloat`,
`idouble`, and `ireal`.
Macros:
TABLE_SV = <table border="1" cellpadding="4" cellspacing="0">
<caption>Special Values</caption>
$0</table>
PLUSMN = ±
NAN = $(RED NAN)
INFIN = ∞
PI = π
Authors: Lars Tandle Kyllingstad, Don Clugston
Copyright: Copyright (c) 2010, Lars T. Kyllingstad.
License: $(HTTP boost.org/LICENSE_1_0.txt, Boost License 1.0)
Source: $(PHOBOSSRC std/complex.d)
*/
module std.complex;
import std.traits;
/** Helper function that returns a complex number with the specified
real and imaginary parts.
Params:
R = (template parameter) type of real part of complex number
I = (template parameter) type of imaginary part of complex number
re = real part of complex number to be constructed
im = (optional) imaginary part of complex number, 0 if omitted.
Returns:
`Complex` instance with real and imaginary parts set
to the values provided as input. If neither `re` nor
`im` are floating-point numbers, the return type will
be `Complex!double`. Otherwise, the return type is
deduced using $(D std.traits.CommonType!(R, I)).
*/
auto complex(R)(const R re) @safe pure nothrow @nogc
if (is(R : double))
{
static if (isFloatingPoint!R)
return Complex!R(re, 0);
else
return Complex!double(re, 0);
}
/// ditto
auto complex(R, I)(const R re, const I im) @safe pure nothrow @nogc
if (is(R : double) && is(I : double))
{
static if (isFloatingPoint!R || isFloatingPoint!I)
return Complex!(CommonType!(R, I))(re, im);
else
return Complex!double(re, im);
}
///
@safe pure nothrow unittest
{
auto a = complex(1.0);
static assert(is(typeof(a) == Complex!double));
assert(a.re == 1.0);
assert(a.im == 0.0);
auto b = complex(2.0L);
static assert(is(typeof(b) == Complex!real));
assert(b.re == 2.0L);
assert(b.im == 0.0L);
auto c = complex(1.0, 2.0);
static assert(is(typeof(c) == Complex!double));
assert(c.re == 1.0);
assert(c.im == 2.0);
auto d = complex(3.0, 4.0L);
static assert(is(typeof(d) == Complex!real));
assert(d.re == 3.0);
assert(d.im == 4.0L);
auto e = complex(1);
static assert(is(typeof(e) == Complex!double));
assert(e.re == 1);
assert(e.im == 0);
auto f = complex(1L, 2);
static assert(is(typeof(f) == Complex!double));
assert(f.re == 1L);
assert(f.im == 2);
auto g = complex(3, 4.0L);
static assert(is(typeof(g) == Complex!real));
assert(g.re == 3);
assert(g.im == 4.0L);
}
/** A complex number parametrised by a type `T`, which must be either
`float`, `double` or `real`.
*/
struct Complex(T)
if (isFloatingPoint!T)
{
import std.format.spec : FormatSpec;
import std.range.primitives : isOutputRange;
/** The real part of the number. */
T re;
/** The imaginary part of the number. */
T im;
/** Converts the complex number to a string representation.
The second form of this function is usually not called directly;
instead, it is used via $(REF format, std,string), as shown in the examples
below. Supported format characters are 'e', 'f', 'g', 'a', and 's'.
See the $(MREF std, format) and $(REF format, std,string)
documentation for more information.
*/
string toString() const @safe /* TODO: pure nothrow */
{
import std.exception : assumeUnique;
char[] buf;
buf.reserve(100);
auto fmt = FormatSpec!char("%s");
toString((const(char)[] s) { buf ~= s; }, fmt);
static trustedAssumeUnique(T)(T t) @trusted { return assumeUnique(t); }
return trustedAssumeUnique(buf);
}
static if (is(T == double))
///
@safe unittest
{
auto c = complex(1.2, 3.4);
// Vanilla toString formatting:
assert(c.toString() == "1.2+3.4i");
// Formatting with std.string.format specs: the precision and width
// specifiers apply to both the real and imaginary parts of the
// complex number.
import std.format : format;
assert(format("%.2f", c) == "1.20+3.40i");
assert(format("%4.1f", c) == " 1.2+ 3.4i");
}
/// ditto
void toString(Writer, Char)(scope Writer w, scope const ref FormatSpec!Char formatSpec) const
if (isOutputRange!(Writer, const(Char)[]))
{
import std.format.write : formatValue;
import std.math.traits : signbit;
import std.range.primitives : put;
formatValue(w, re, formatSpec);
if (signbit(im) == 0)
put(w, "+");
formatValue(w, im, formatSpec);
put(w, "i");
}
@safe pure nothrow @nogc:
/** Construct a complex number with the specified real and
imaginary parts. In the case where a single argument is passed
that is not complex, the imaginary part of the result will be
zero.
*/
this(R : T)(Complex!R z)
{
re = z.re;
im = z.im;
}
/// ditto
this(Rx : T, Ry : T)(const Rx x, const Ry y)
{
re = x;
im = y;
}
/// ditto
this(R : T)(const R r)
{
re = r;
im = 0;
}
// ASSIGNMENT OPERATORS
// this = complex
ref Complex opAssign(R : T)(Complex!R z)
{
re = z.re;
im = z.im;
return this;
}
// this = numeric
ref Complex opAssign(R : T)(const R r)
{
re = r;
im = 0;
return this;
}
// COMPARISON OPERATORS
// this == complex
bool opEquals(R : T)(Complex!R z) const
{
return re == z.re && im == z.im;
}
// this == numeric
bool opEquals(R : T)(const R r) const
{
return re == r && im == 0;
}
// UNARY OPERATORS
// +complex
Complex opUnary(string op)() const
if (op == "+")
{
return this;
}
// -complex
Complex opUnary(string op)() const
if (op == "-")
{
return Complex(-re, -im);
}
// BINARY OPERATORS
// complex op complex
Complex!(CommonType!(T,R)) opBinary(string op, R)(Complex!R z) const
{
alias C = typeof(return);
auto w = C(this.re, this.im);
return w.opOpAssign!(op)(z);
}
// complex op numeric
Complex!(CommonType!(T,R)) opBinary(string op, R)(const R r) const
if (isNumeric!R)
{
alias C = typeof(return);
auto w = C(this.re, this.im);
return w.opOpAssign!(op)(r);
}
// numeric + complex, numeric * complex
Complex!(CommonType!(T, R)) opBinaryRight(string op, R)(const R r) const
if ((op == "+" || op == "*") && (isNumeric!R))
{
return opBinary!(op)(r);
}
// numeric - complex
Complex!(CommonType!(T, R)) opBinaryRight(string op, R)(const R r) const
if (op == "-" && isNumeric!R)
{
return Complex(r - re, -im);
}
// numeric / complex
Complex!(CommonType!(T, R)) opBinaryRight(string op, R)(const R r) const
if (op == "/" && isNumeric!R)
{
version (FastMath)
{
// Compute norm(this)
immutable norm = re * re + im * im;
// Compute r * conj(this)
immutable prod_re = r * re;
immutable prod_im = r * -im;
// Divide the product by the norm
typeof(return) w = void;
w.re = prod_re / norm;
w.im = prod_im / norm;
return w;
}
else
{
import core.math : fabs;
typeof(return) w = void;
if (fabs(re) < fabs(im))
{
immutable ratio = re/im;
immutable rdivd = r/(re*ratio + im);
w.re = rdivd*ratio;
w.im = -rdivd;
}
else
{
immutable ratio = im/re;
immutable rdivd = r/(re + im*ratio);
w.re = rdivd;
w.im = -rdivd*ratio;
}
return w;
}
}
// numeric ^^ complex
Complex!(CommonType!(T, R)) opBinaryRight(string op, R)(const R lhs) const
if (op == "^^" && isNumeric!R)
{
import core.math : cos, sin;
import std.math.exponential : exp, log;
import std.math.constants : PI;
Unqual!(CommonType!(T, R)) ab = void, ar = void;
if (lhs >= 0)
{
// r = lhs
// theta = 0
ab = lhs ^^ this.re;
ar = log(lhs) * this.im;
}
else
{
// r = -lhs
// theta = PI
ab = (-lhs) ^^ this.re * exp(-PI * this.im);
ar = PI * this.re + log(-lhs) * this.im;
}
return typeof(return)(ab * cos(ar), ab * sin(ar));
}
// OP-ASSIGN OPERATORS
// complex += complex, complex -= complex
ref Complex opOpAssign(string op, C)(const C z)
if ((op == "+" || op == "-") && is(C R == Complex!R))
{
mixin ("re "~op~"= z.re;");
mixin ("im "~op~"= z.im;");
return this;
}
// complex *= complex
ref Complex opOpAssign(string op, C)(const C z)
if (op == "*" && is(C R == Complex!R))
{
auto temp = re*z.re - im*z.im;
im = im*z.re + re*z.im;
re = temp;
return this;
}
// complex /= complex
ref Complex opOpAssign(string op, C)(const C z)
if (op == "/" && is(C R == Complex!R))
{
version (FastMath)
{
// Compute norm(z)
immutable norm = z.re * z.re + z.im * z.im;
// Compute this * conj(z)
immutable prod_re = re * z.re - im * -z.im;
immutable prod_im = im * z.re + re * -z.im;
// Divide the product by the norm
re = prod_re / norm;
im = prod_im / norm;
return this;
}
else
{
import core.math : fabs;
if (fabs(z.re) < fabs(z.im))
{
immutable ratio = z.re/z.im;
immutable denom = z.re*ratio + z.im;
immutable temp = (re*ratio + im)/denom;
im = (im*ratio - re)/denom;
re = temp;
}
else
{
immutable ratio = z.im/z.re;
immutable denom = z.re + z.im*ratio;
immutable temp = (re + im*ratio)/denom;
im = (im - re*ratio)/denom;
re = temp;
}
return this;
}
}
// complex ^^= complex
ref Complex opOpAssign(string op, C)(const C z)
if (op == "^^" && is(C R == Complex!R))
{
import core.math : cos, sin;
import std.math.exponential : exp, log;
immutable r = abs(this);
immutable t = arg(this);
immutable ab = r^^z.re * exp(-t*z.im);
immutable ar = t*z.re + log(r)*z.im;
re = ab*cos(ar);
im = ab*sin(ar);
return this;
}
// complex += numeric, complex -= numeric
ref Complex opOpAssign(string op, U : T)(const U a)
if (op == "+" || op == "-")
{
mixin ("re "~op~"= a;");
return this;
}
// complex *= numeric, complex /= numeric
ref Complex opOpAssign(string op, U : T)(const U a)
if (op == "*" || op == "/")
{
mixin ("re "~op~"= a;");
mixin ("im "~op~"= a;");
return this;
}
// complex ^^= real
ref Complex opOpAssign(string op, R)(const R r)
if (op == "^^" && isFloatingPoint!R)
{
import core.math : cos, sin;
immutable ab = abs(this)^^r;
immutable ar = arg(this)*r;
re = ab*cos(ar);
im = ab*sin(ar);
return this;
}
// complex ^^= int
ref Complex opOpAssign(string op, U)(const U i)
if (op == "^^" && isIntegral!U)
{
switch (i)
{
case 0:
re = 1.0;
im = 0.0;
break;
case 1:
// identity; do nothing
break;
case 2:
this *= this;
break;
case 3:
auto z = this;
this *= z;
this *= z;
break;
default:
this ^^= cast(real) i;
}
return this;
}
/** Returns a complex number instance that correponds in size and in ABI
to the associated C compiler's `_Complex` type.
*/
auto toNative()
{
import core.stdc.config : c_complex_float, c_complex_double, c_complex_real;
static if (is(T == float))
return c_complex_float(re, im);
else static if (is(T == double))
return c_complex_double(re, im);
else
return c_complex_real(re, im);
}
}
@safe pure nothrow unittest
{
import std.complex;
static import core.math;
import std.math;
enum EPS = double.epsilon;
auto c1 = complex(1.0, 1.0);
// Check unary operations.
auto c2 = Complex!double(0.5, 2.0);
assert(c2 == +c2);
assert((-c2).re == -(c2.re));
assert((-c2).im == -(c2.im));
assert(c2 == -(-c2));
// Check complex-complex operations.
auto cpc = c1 + c2;
assert(cpc.re == c1.re + c2.re);
assert(cpc.im == c1.im + c2.im);
auto cmc = c1 - c2;
assert(cmc.re == c1.re - c2.re);
assert(cmc.im == c1.im - c2.im);
auto ctc = c1 * c2;
assert(isClose(abs(ctc), abs(c1)*abs(c2), EPS));
assert(isClose(arg(ctc), arg(c1)+arg(c2), EPS));
auto cdc = c1 / c2;
assert(isClose(abs(cdc), abs(c1)/abs(c2), EPS));
assert(isClose(arg(cdc), arg(c1)-arg(c2), EPS));
auto cec = c1^^c2;
assert(isClose(cec.re, 0.1152413197994, 1e-12));
assert(isClose(cec.im, 0.2187079045274, 1e-12));
// Check complex-real operations.
double a = 123.456;
auto cpr = c1 + a;
assert(cpr.re == c1.re + a);
assert(cpr.im == c1.im);
auto cmr = c1 - a;
assert(cmr.re == c1.re - a);
assert(cmr.im == c1.im);
auto ctr = c1 * a;
assert(ctr.re == c1.re*a);
assert(ctr.im == c1.im*a);
auto cdr = c1 / a;
assert(isClose(abs(cdr), abs(c1)/a, EPS));
assert(isClose(arg(cdr), arg(c1), EPS));
auto cer = c1^^3.0;
assert(isClose(abs(cer), abs(c1)^^3, EPS));
assert(isClose(arg(cer), arg(c1)*3, EPS));
auto rpc = a + c1;
assert(rpc == cpr);
auto rmc = a - c1;
assert(rmc.re == a-c1.re);
assert(rmc.im == -c1.im);
auto rtc = a * c1;
assert(rtc == ctr);
auto rdc = a / c1;
assert(isClose(abs(rdc), a/abs(c1), EPS));
assert(isClose(arg(rdc), -arg(c1), EPS));
rdc = a / c2;
assert(isClose(abs(rdc), a/abs(c2), EPS));
assert(isClose(arg(rdc), -arg(c2), EPS));
auto rec1a = 1.0 ^^ c1;
assert(rec1a.re == 1.0);
assert(rec1a.im == 0.0);
auto rec2a = 1.0 ^^ c2;
assert(rec2a.re == 1.0);
assert(rec2a.im == 0.0);
auto rec1b = (-1.0) ^^ c1;
assert(isClose(abs(rec1b), std.math.exp(-PI * c1.im), EPS));
auto arg1b = arg(rec1b);
/* The argument _should_ be PI, but floating-point rounding error
* means that in fact the imaginary part is very slightly negative.
*/
assert(isClose(arg1b, PI, EPS) || isClose(arg1b, -PI, EPS));
auto rec2b = (-1.0) ^^ c2;
assert(isClose(abs(rec2b), std.math.exp(-2 * PI), EPS));
assert(isClose(arg(rec2b), PI_2, EPS));
auto rec3a = 0.79 ^^ complex(6.8, 5.7);
auto rec3b = complex(0.79, 0.0) ^^ complex(6.8, 5.7);
assert(isClose(rec3a.re, rec3b.re, 1e-14));
assert(isClose(rec3a.im, rec3b.im, 1e-14));
auto rec4a = (-0.79) ^^ complex(6.8, 5.7);
auto rec4b = complex(-0.79, 0.0) ^^ complex(6.8, 5.7);
assert(isClose(rec4a.re, rec4b.re, 1e-14));
assert(isClose(rec4a.im, rec4b.im, 1e-14));
auto rer = a ^^ complex(2.0, 0.0);
auto rcheck = a ^^ 2.0;
static assert(is(typeof(rcheck) == double));
assert(feqrel(rer.re, rcheck) == double.mant_dig);
assert(isIdentical(rer.re, rcheck));
assert(rer.im == 0.0);
auto rer2 = (-a) ^^ complex(2.0, 0.0);
rcheck = (-a) ^^ 2.0;
assert(feqrel(rer2.re, rcheck) == double.mant_dig);
assert(isIdentical(rer2.re, rcheck));
assert(isClose(rer2.im, 0.0, 0.0, 1e-10));
auto rer3 = (-a) ^^ complex(-2.0, 0.0);
rcheck = (-a) ^^ (-2.0);
assert(feqrel(rer3.re, rcheck) == double.mant_dig);
assert(isIdentical(rer3.re, rcheck));
assert(isClose(rer3.im, 0.0, 0.0, EPS));
auto rer4 = a ^^ complex(-2.0, 0.0);
rcheck = a ^^ (-2.0);
assert(feqrel(rer4.re, rcheck) == double.mant_dig);
assert(isIdentical(rer4.re, rcheck));
assert(rer4.im == 0.0);
// Check Complex-int operations.
foreach (i; 0 .. 6)
{
auto cei = c1^^i;
assert(isClose(abs(cei), abs(c1)^^i, 1e-14));
// Use cos() here to deal with arguments that go outside
// the (-pi,pi] interval (only an issue for i>3).
assert(isClose(core.math.cos(arg(cei)), core.math.cos(arg(c1)*i), 1e-14));
}
// Check operations between different complex types.
auto cf = Complex!float(1.0, 1.0);
auto cr = Complex!real(1.0, 1.0);
auto c1pcf = c1 + cf;
auto c1pcr = c1 + cr;
static assert(is(typeof(c1pcf) == Complex!double));
static assert(is(typeof(c1pcr) == Complex!real));
assert(c1pcf.re == c1pcr.re);
assert(c1pcf.im == c1pcr.im);
auto c1c = c1;
auto c2c = c2;
c1c /= c1;
assert(isClose(c1c.re, 1.0, EPS));
assert(isClose(c1c.im, 0.0, 0.0, EPS));
c1c = c1;
c1c /= c2;
assert(isClose(c1c.re, 0.5882352941177, 1e-12));
assert(isClose(c1c.im, -0.3529411764706, 1e-12));
c2c /= c1;
assert(isClose(c2c.re, 1.25, EPS));
assert(isClose(c2c.im, 0.75, EPS));
c2c = c2;
c2c /= c2;
assert(isClose(c2c.re, 1.0, EPS));
assert(isClose(c2c.im, 0.0, 0.0, EPS));
}
@safe pure nothrow unittest
{
// Initialization
Complex!double a = 1;
assert(a.re == 1 && a.im == 0);
Complex!double b = 1.0;
assert(b.re == 1.0 && b.im == 0);
Complex!double c = Complex!real(1.0, 2);
assert(c.re == 1.0 && c.im == 2);
}
@safe pure nothrow unittest
{
// Assignments and comparisons
Complex!double z;
z = 1;
assert(z == 1);
assert(z.re == 1.0 && z.im == 0.0);
z = 2.0;
assert(z == 2.0);
assert(z.re == 2.0 && z.im == 0.0);
z = 1.0L;
assert(z == 1.0L);
assert(z.re == 1.0 && z.im == 0.0);
auto w = Complex!real(1.0, 1.0);
z = w;
assert(z == w);
assert(z.re == 1.0 && z.im == 1.0);
auto c = Complex!float(2.0, 2.0);
z = c;
assert(z == c);
assert(z.re == 2.0 && z.im == 2.0);
}
/* Makes Complex!(Complex!T) fold to Complex!T.
The rationale for this is that just like the real line is a
subspace of the complex plane, the complex plane is a subspace
of itself. Example of usage:
---
Complex!T addI(T)(T x)
{
return x + Complex!T(0.0, 1.0);
}
---
The above will work if T is both real and complex.
*/
template Complex(T)
if (is(T R == Complex!R))
{
alias Complex = T;
}
@safe pure nothrow unittest
{
static assert(is(Complex!(Complex!real) == Complex!real));
Complex!T addI(T)(T x)
{
return x + Complex!T(0.0, 1.0);
}
auto z1 = addI(1.0);
assert(z1.re == 1.0 && z1.im == 1.0);
enum one = Complex!double(1.0, 0.0);
auto z2 = addI(one);
assert(z1 == z2);
}
/**
Params: z = A complex number.
Returns: The absolute value (or modulus) of `z`.
*/
T abs(T)(Complex!T z) @safe pure nothrow @nogc
{
import std.math.algebraic : hypot;
return hypot(z.re, z.im);
}
///
@safe pure nothrow unittest
{
static import core.math;
assert(abs(complex(1.0)) == 1.0);
assert(abs(complex(0.0, 1.0)) == 1.0);
assert(abs(complex(1.0L, -2.0L)) == core.math.sqrt(5.0L));
}
@safe pure nothrow @nogc unittest
{
static import core.math;
assert(abs(complex(0.0L, -3.2L)) == 3.2L);
assert(abs(complex(0.0L, 71.6L)) == 71.6L);
assert(abs(complex(-1.0L, 1.0L)) == core.math.sqrt(2.0L));
}
@safe pure nothrow @nogc unittest
{
import std.meta : AliasSeq;
static foreach (T; AliasSeq!(float, double, real))
{{
static import std.math;
Complex!T a = complex(T(-12), T(3));
T b = std.math.hypot(a.re, a.im);
assert(std.math.isClose(abs(a), b));
assert(std.math.isClose(abs(-a), b));
}}
}
/++
Params:
z = A complex number.
x = A real number.
Returns: The squared modulus of `z`.
For genericity, if called on a real number, returns its square.
+/
T sqAbs(T)(Complex!T z) @safe pure nothrow @nogc
{
return z.re*z.re + z.im*z.im;
}
///
@safe pure nothrow unittest
{
import std.math.operations : isClose;
assert(sqAbs(complex(0.0)) == 0.0);
assert(sqAbs(complex(1.0)) == 1.0);
assert(sqAbs(complex(0.0, 1.0)) == 1.0);
assert(isClose(sqAbs(complex(1.0L, -2.0L)), 5.0L));
assert(isClose(sqAbs(complex(-3.0L, 1.0L)), 10.0L));
assert(isClose(sqAbs(complex(1.0f,-1.0f)), 2.0f));
}
/// ditto
T sqAbs(T)(const T x) @safe pure nothrow @nogc
if (isFloatingPoint!T)
{
return x*x;
}
@safe pure nothrow unittest
{
import std.math.operations : isClose;
assert(sqAbs(0.0) == 0.0);
assert(sqAbs(-1.0) == 1.0);
assert(isClose(sqAbs(-3.0L), 9.0L));
assert(isClose(sqAbs(-5.0f), 25.0f));
}
/**
Params: z = A complex number.
Returns: The argument (or phase) of `z`.
*/
T arg(T)(Complex!T z) @safe pure nothrow @nogc
{
import std.math.trigonometry : atan2;
return atan2(z.im, z.re);
}
///
@safe pure nothrow unittest
{
import std.math.constants : PI_2, PI_4;
assert(arg(complex(1.0)) == 0.0);
assert(arg(complex(0.0L, 1.0L)) == PI_2);
assert(arg(complex(1.0L, 1.0L)) == PI_4);
}
/**
* Extracts the norm of a complex number.
* Params:
* z = A complex number
* Returns:
* The squared magnitude of `z`.
*/
T norm(T)(Complex!T z) @safe pure nothrow @nogc
{
return z.re * z.re + z.im * z.im;
}
///
@safe pure nothrow @nogc unittest
{
import std.math.operations : isClose;
import std.math.constants : PI;
assert(norm(complex(3.0, 4.0)) == 25.0);
assert(norm(fromPolar(5.0, 0.0)) == 25.0);
assert(isClose(norm(fromPolar(5.0L, PI / 6)), 25.0L));
assert(isClose(norm(fromPolar(5.0L, 13 * PI / 6)), 25.0L));
}
/**
Params: z = A complex number.
Returns: The complex conjugate of `z`.
*/
Complex!T conj(T)(Complex!T z) @safe pure nothrow @nogc
{
return Complex!T(z.re, -z.im);
}
///
@safe pure nothrow unittest
{
assert(conj(complex(1.0)) == complex(1.0));
assert(conj(complex(1.0, 2.0)) == complex(1.0, -2.0));
}
@safe pure nothrow @nogc unittest
{
import std.meta : AliasSeq;
static foreach (T; AliasSeq!(float, double, real))
{{
auto c = Complex!T(7, 3L);
assert(conj(c) == Complex!T(7, -3L));
auto z = Complex!T(0, -3.2L);
assert(conj(z) == -z);
}}
}
/**
* Returns the projection of `z` onto the Riemann sphere.
* Params:
* z = A complex number
* Returns:
* The projection of `z` onto the Riemann sphere.
*/
Complex!T proj(T)(Complex!T z)
{
static import std.math;
if (std.math.isInfinity(z.re) || std.math.isInfinity(z.im))
return Complex!T(T.infinity, std.math.copysign(0.0, z.im));
return z;
}
///
@safe pure nothrow unittest
{
assert(proj(complex(1.0)) == complex(1.0));
assert(proj(complex(double.infinity, 5.0)) == complex(double.infinity, 0.0));
assert(proj(complex(5.0, -double.infinity)) == complex(double.infinity, -0.0));
}
/**
Constructs a complex number given its absolute value and argument.
Params:
modulus = The modulus
argument = The argument
Returns: The complex number with the given modulus and argument.
*/
Complex!(CommonType!(T, U)) fromPolar(T, U)(const T modulus, const U argument)
@safe pure nothrow @nogc
{
import core.math : sin, cos;
return Complex!(CommonType!(T,U))
(modulus*cos(argument), modulus*sin(argument));
}
///
@safe pure nothrow unittest
{
import core.math;
import std.math.operations : isClose;
import std.math.algebraic : sqrt;
import std.math.constants : PI_4;
auto z = fromPolar(core.math.sqrt(2.0L), PI_4);
assert(isClose(z.re, 1.0L));
assert(isClose(z.im, 1.0L));
}
version (StdUnittest)
{
// Helper function for comparing two Complex numbers.
int ceqrel(T)(const Complex!T x, const Complex!T y) @safe pure nothrow @nogc
{
import std.math.operations : feqrel;
const r = feqrel(x.re, y.re);
const i = feqrel(x.im, y.im);
return r < i ? r : i;
}
}
/**
Trigonometric functions on complex numbers.
Params: z = A complex number.
Returns: The sine, cosine and tangent of `z`, respectively.
*/
Complex!T sin(T)(Complex!T z) @safe pure nothrow @nogc
{
auto cs = expi(z.re);
auto csh = coshisinh(z.im);
return typeof(return)(cs.im * csh.re, cs.re * csh.im);
}
///
@safe pure nothrow unittest
{
static import core.math;
assert(sin(complex(0.0)) == 0.0);
assert(sin(complex(2.0, 0)) == core.math.sin(2.0));
}
@safe pure nothrow unittest
{
static import core.math;
assert(ceqrel(sin(complex(2.0L, 0)), complex(core.math.sin(2.0L))) >= real.mant_dig - 1);
}
/// ditto
Complex!T cos(T)(Complex!T z) @safe pure nothrow @nogc
{
auto cs = expi(z.re);
auto csh = coshisinh(z.im);
return typeof(return)(cs.re * csh.re, - cs.im * csh.im);
}
///
@safe pure nothrow unittest
{
static import core.math;
static import std.math;
assert(cos(complex(0.0)) == 1.0);
assert(cos(complex(1.3, 0.0)) == core.math.cos(1.3));
assert(cos(complex(0.0, 5.2)) == std.math.cosh(5.2));
}
@safe pure nothrow unittest
{
static import core.math;
static import std.math;
assert(ceqrel(cos(complex(0, 5.2L)), complex(std.math.cosh(5.2L), 0.0L)) >= real.mant_dig - 1);
assert(ceqrel(cos(complex(1.3L)), complex(core.math.cos(1.3L))) >= real.mant_dig - 1);
}
/// ditto
Complex!T tan(T)(Complex!T z) @safe pure nothrow @nogc
{
return sin(z) / cos(z);
}
///
@safe pure nothrow @nogc unittest
{
static import std.math;
int ceqrel(T)(const Complex!T x, const Complex!T y) @safe pure nothrow @nogc
{
import std.math.operations : feqrel;
const r = feqrel(x.re, y.re);
const i = feqrel(x.im, y.im);
return r < i ? r : i;
}
assert(ceqrel(tan(complex(1.0, 0.0)), complex(std.math.tan(1.0), 0.0)) >= double.mant_dig - 2);
assert(ceqrel(tan(complex(0.0, 1.0)), complex(0.0, std.math.tanh(1.0))) >= double.mant_dig - 2);
}
/**
Inverse trigonometric functions on complex numbers.
Params: z = A complex number.
Returns: The arcsine, arccosine and arctangent of `z`, respectively.
*/
Complex!T asin(T)(Complex!T z) @safe pure nothrow @nogc
{
auto ash = asinh(Complex!T(-z.im, z.re));
return Complex!T(ash.im, -ash.re);
}
///
@safe pure nothrow unittest
{
import std.math.operations : isClose;
import std.math.constants : PI;
assert(asin(complex(0.0)) == 0.0);
assert(isClose(asin(complex(0.5L)), PI / 6));
}
@safe pure nothrow unittest
{
import std.math.operations : isClose;
import std.math.constants : PI;
version (DigitalMars) {} else // Disabled because of issue 21376
assert(isClose(asin(complex(0.5f)), float(PI) / 6));
}
/// ditto
Complex!T acos(T)(Complex!T z) @safe pure nothrow @nogc
{
static import std.math;
auto as = asin(z);
return Complex!T(T(std.math.PI_2) - as.re, as.im);
}
///
@safe pure nothrow unittest
{
import std.math.operations : isClose;
import std.math.constants : PI;
import std.math.trigonometry : std_math_acos = acos;
assert(acos(complex(0.0)) == std_math_acos(0.0));
assert(isClose(acos(complex(0.5L)), PI / 3));
}
@safe pure nothrow unittest
{
import std.math.operations : isClose;
import std.math.constants : PI;
version (DigitalMars) {} else // Disabled because of issue 21376
assert(isClose(acos(complex(0.5f)), float(PI) / 3));
}
/// ditto
Complex!T atan(T)(Complex!T z) @safe pure nothrow @nogc
{
static import std.math;
const T re2 = z.re * z.re;
const T x = 1 - re2 - z.im * z.im;
T num = z.im + 1;
T den = z.im - 1;
num = re2 + num * num;
den = re2 + den * den;
return Complex!T(T(0.5) * std.math.atan2(2 * z.re, x),
T(0.25) * std.math.log(num / den));
}
///
@safe pure nothrow @nogc unittest
{
import std.math.operations : isClose;
import std.math.constants : PI;
assert(atan(complex(0.0)) == 0.0);
assert(isClose(atan(sqrt(complex(3.0L))), PI / 3));
assert(isClose(atan(sqrt(complex(3.0f))), float(PI) / 3));
}
/**
Hyperbolic trigonometric functions on complex numbers.
Params: z = A complex number.
Returns: The hyperbolic sine, cosine and tangent of `z`, respectively.
*/
Complex!T sinh(T)(Complex!T z) @safe pure nothrow @nogc
{
static import core.math, std.math;
return Complex!T(std.math.sinh(z.re) * core.math.cos(z.im),
std.math.cosh(z.re) * core.math.sin(z.im));
}
///
@safe pure nothrow unittest
{
static import std.math;
assert(sinh(complex(0.0)) == 0.0);
assert(sinh(complex(1.0L)) == std.math.sinh(1.0L));
assert(sinh(complex(1.0f)) == std.math.sinh(1.0f));
}
/// ditto
Complex!T cosh(T)(Complex!T z) @safe pure nothrow @nogc
{
static import core.math, std.math;
return Complex!T(std.math.cosh(z.re) * core.math.cos(z.im),
std.math.sinh(z.re) * core.math.sin(z.im));
}
///
@safe pure nothrow unittest
{
static import std.math;
assert(cosh(complex(0.0)) == 1.0);
assert(cosh(complex(1.0L)) == std.math.cosh(1.0L));
assert(cosh(complex(1.0f)) == std.math.cosh(1.0f));
}
/// ditto
Complex!T tanh(T)(Complex!T z) @safe pure nothrow @nogc
{
return sinh(z) / cosh(z);
}
///
@safe pure nothrow @nogc unittest
{
import std.math.operations : isClose;
import std.math.trigonometry : std_math_tanh = tanh;
assert(tanh(complex(0.0)) == 0.0);
assert(isClose(tanh(complex(1.0L)), std_math_tanh(1.0L)));
assert(isClose(tanh(complex(1.0f)), std_math_tanh(1.0f)));
}
/**
Inverse hyperbolic trigonometric functions on complex numbers.
Params: z = A complex number.
Returns: The hyperbolic arcsine, arccosine and arctangent of `z`, respectively.
*/
Complex!T asinh(T)(Complex!T z) @safe pure nothrow @nogc
{
auto t = Complex!T((z.re - z.im) * (z.re + z.im) + 1, 2 * z.re * z.im);
return log(sqrt(t) + z);
}
///
@safe pure nothrow unittest
{
import std.math.operations : isClose;
import std.math.trigonometry : std_math_asinh = asinh;
assert(asinh(complex(0.0)) == 0.0);
assert(isClose(asinh(complex(1.0L)), std_math_asinh(1.0L)));
assert(isClose(asinh(complex(1.0f)), std_math_asinh(1.0f)));
}
/// ditto
Complex!T acosh(T)(Complex!T z) @safe pure nothrow @nogc
{
return 2 * log(sqrt(T(0.5) * (z + 1)) + sqrt(T(0.5) * (z - 1)));
}
///
@safe pure nothrow unittest
{
import std.math.operations : isClose;
import std.math.trigonometry : std_math_acosh = acosh;
assert(acosh(complex(1.0)) == 0.0);
assert(isClose(acosh(complex(3.0L)), std_math_acosh(3.0L)));
assert(isClose(acosh(complex(3.0f)), std_math_acosh(3.0f)));
}
/// ditto
Complex!T atanh(T)(Complex!T z) @safe pure nothrow @nogc
{
static import std.math;
const T im2 = z.im * z.im;
const T x = 1 - im2 - z.re * z.re;
T num = 1 + z.re;
T den = 1 - z.re;
num = im2 + num * num;
den = im2 + den * den;
return Complex!T(T(0.25) * (std.math.log(num) - std.math.log(den)),
T(0.5) * std.math.atan2(2 * z.im, x));
}
///
@safe pure nothrow @nogc unittest
{
import std.math.operations : isClose;
import std.math.trigonometry : std_math_atanh = atanh;
assert(atanh(complex(0.0)) == 0.0);
assert(isClose(atanh(complex(0.5L)), std_math_atanh(0.5L)));
assert(isClose(atanh(complex(0.5f)), std_math_atanh(0.5f)));
}
/**
Params: y = A real number.
Returns: The value of cos(y) + i sin(y).
Note:
`expi` is included here for convenience and for easy migration of code.
*/
Complex!real expi(real y) @trusted pure nothrow @nogc
{
import core.math : cos, sin;
return Complex!real(cos(y), sin(y));
}
///
@safe pure nothrow unittest
{
import core.math : cos, sin;
assert(expi(0.0L) == 1.0L);
assert(expi(1.3e5L) == complex(cos(1.3e5L), sin(1.3e5L)));
}
/**
Params: y = A real number.
Returns: The value of cosh(y) + i sinh(y)
Note:
`coshisinh` is included here for convenience and for easy migration of code.
*/
Complex!real coshisinh(real y) @safe pure nothrow @nogc
{
static import core.math;
static import std.math;
if (core.math.fabs(y) <= 0.5)
return Complex!real(std.math.cosh(y), std.math.sinh(y));
else
{
auto z = std.math.exp(y);
auto zi = 0.5 / z;
z = 0.5 * z;
return Complex!real(z + zi, z - zi);
}
}
///
@safe pure nothrow @nogc unittest
{
import std.math.trigonometry : cosh, sinh;
assert(coshisinh(3.0L) == complex(cosh(3.0L), sinh(3.0L)));
}
/**
Params: z = A complex number.
Returns: The square root of `z`.
*/
Complex!T sqrt(T)(Complex!T z) @safe pure nothrow @nogc
{
static import core.math;
typeof(return) c;
real x,y,w,r;
if (z == 0)
{
c = typeof(return)(0, 0);
}
else
{
real z_re = z.re;
real z_im = z.im;
x = core.math.fabs(z_re);
y = core.math.fabs(z_im);
if (x >= y)
{
r = y / x;
w = core.math.sqrt(x)
* core.math.sqrt(0.5 * (1 + core.math.sqrt(1 + r * r)));
}
else
{
r = x / y;
w = core.math.sqrt(y)
* core.math.sqrt(0.5 * (r + core.math.sqrt(1 + r * r)));
}
if (z_re >= 0)
{
c = typeof(return)(w, z_im / (w + w));
}
else
{
if (z_im < 0)
w = -w;
c = typeof(return)(z_im / (w + w), w);
}
}
return c;
}
///
@safe pure nothrow unittest
{
static import core.math;
assert(sqrt(complex(0.0)) == 0.0);
assert(sqrt(complex(1.0L, 0)) == core.math.sqrt(1.0L));
assert(sqrt(complex(-1.0L, 0)) == complex(0, 1.0L));
assert(sqrt(complex(-8.0, -6.0)) == complex(1.0, -3.0));
}
@safe pure nothrow unittest
{
import std.math.operations : isClose;
auto c1 = complex(1.0, 1.0);
auto c2 = Complex!double(0.5, 2.0);
auto c1s = sqrt(c1);
assert(isClose(c1s.re, 1.09868411347));
assert(isClose(c1s.im, 0.455089860562));
auto c2s = sqrt(c2);
assert(isClose(c2s.re, 1.13171392428));
assert(isClose(c2s.im, 0.883615530876));
}
// support %f formatting of complex numbers
// https://issues.dlang.org/show_bug.cgi?id=10881
@safe unittest
{
import std.format : format;
auto x = complex(1.2, 3.4);
assert(format("%.2f", x) == "1.20+3.40i");
auto y = complex(1.2, -3.4);
assert(format("%.2f", y) == "1.20-3.40i");
}
@safe unittest
{
// Test wide string formatting
import std.format.write : formattedWrite;
wstring wformat(T)(string format, Complex!T c)
{
import std.array : appender;
auto w = appender!wstring();
auto n = formattedWrite(w, format, c);
return w.data;
}
auto x = complex(1.2, 3.4);
assert(wformat("%.2f", x) == "1.20+3.40i"w);
}
@safe unittest
{
// Test ease of use (vanilla toString() should be supported)
assert(complex(1.2, 3.4).toString() == "1.2+3.4i");
}
@safe pure nothrow @nogc unittest
{
auto c = complex(3.0L, 4.0L);
c = sqrt(c);
assert(c.re == 2.0L);
assert(c.im == 1.0L);
}
/**
* Calculates e$(SUPERSCRIPT x).
* Params:
* x = A complex number
* Returns:
* The complex base e exponential of `x`
*
* $(TABLE_SV
* $(TR $(TH x) $(TH exp(x)))
* $(TR $(TD ($(PLUSMN)0, +0)) $(TD (1, +0)))
* $(TR $(TD (any, +$(INFIN))) $(TD ($(NAN), $(NAN))))
* $(TR $(TD (any, $(NAN)) $(TD ($(NAN), $(NAN)))))
* $(TR $(TD (+$(INFIN), +0)) $(TD (+$(INFIN), +0)))
* $(TR $(TD (-$(INFIN), any)) $(TD ($(PLUSMN)0, cis(x.im))))
* $(TR $(TD (+$(INFIN), any)) $(TD ($(PLUSMN)$(INFIN), cis(x.im))))
* $(TR $(TD (-$(INFIN), +$(INFIN))) $(TD ($(PLUSMN)0, $(PLUSMN)0)))
* $(TR $(TD (+$(INFIN), +$(INFIN))) $(TD ($(PLUSMN)$(INFIN), $(NAN))))
* $(TR $(TD (-$(INFIN), $(NAN))) $(TD ($(PLUSMN)0, $(PLUSMN)0)))
* $(TR $(TD (+$(INFIN), $(NAN))) $(TD ($(PLUSMN)$(INFIN), $(NAN))))
* $(TR $(TD ($(NAN), +0)) $(TD ($(NAN), +0)))
* $(TR $(TD ($(NAN), any)) $(TD ($(NAN), $(NAN))))
* $(TR $(TD ($(NAN), $(NAN))) $(TD ($(NAN), $(NAN))))
* )
*/
Complex!T exp(T)(Complex!T x) @trusted pure nothrow @nogc // TODO: @safe
{
static import std.math;
// Handle special cases explicitly here, as fromPolar will otherwise
// cause them to return Complex!T(NaN, NaN), or with the wrong sign.
if (std.math.isInfinity(x.re))
{
if (std.math.isNaN(x.im))
{
if (std.math.signbit(x.re))
return Complex!T(0, std.math.copysign(0, x.im));
else
return x;
}
if (std.math.isInfinity(x.im))
{
if (std.math.signbit(x.re))
return Complex!T(0, std.math.copysign(0, x.im));
else
return Complex!T(T.infinity, -T.nan);
}
if (x.im == 0.0)
{
if (std.math.signbit(x.re))
return Complex!T(0.0);
else
return Complex!T(T.infinity);
}
}
if (std.math.isNaN(x.re))
{
if (std.math.isNaN(x.im) || std.math.isInfinity(x.im))
return Complex!T(T.nan, T.nan);
if (x.im == 0.0)
return x;
}
if (x.re == 0.0)
{
if (std.math.isNaN(x.im) || std.math.isInfinity(x.im))
return Complex!T(T.nan, T.nan);
if (x.im == 0.0)
return Complex!T(1.0, 0.0);
}
return fromPolar!(T, T)(std.math.exp(x.re), x.im);
}
///
@safe pure nothrow @nogc unittest
{
import std.math.operations : isClose;
import std.math.constants : PI;
assert(exp(complex(0.0, 0.0)) == complex(1.0, 0.0));
auto a = complex(2.0, 1.0);
assert(exp(conj(a)) == conj(exp(a)));
auto b = exp(complex(0.0L, 1.0L) * PI);
assert(isClose(b, -1.0L, 0.0, 1e-15));
}
@safe pure nothrow @nogc unittest
{
import std.math.traits : isNaN, isInfinity;
auto a = exp(complex(0.0, double.infinity));
assert(a.re.isNaN && a.im.isNaN);
auto b = exp(complex(0.0, double.infinity));
assert(b.re.isNaN && b.im.isNaN);
auto c = exp(complex(0.0, double.nan));
assert(c.re.isNaN && c.im.isNaN);
auto d = exp(complex(+double.infinity, 0.0));
assert(d == complex(double.infinity, 0.0));
auto e = exp(complex(-double.infinity, 0.0));
assert(e == complex(0.0));
auto f = exp(complex(-double.infinity, 1.0));
assert(f == complex(0.0));
auto g = exp(complex(+double.infinity, 1.0));
assert(g == complex(double.infinity, double.infinity));
auto h = exp(complex(-double.infinity, +double.infinity));
assert(h == complex(0.0));
auto i = exp(complex(+double.infinity, +double.infinity));
assert(i.re.isInfinity && i.im.isNaN);
auto j = exp(complex(-double.infinity, double.nan));
assert(j == complex(0.0));
auto k = exp(complex(+double.infinity, double.nan));
assert(k.re.isInfinity && k.im.isNaN);
auto l = exp(complex(double.nan, 0));
assert(l.re.isNaN && l.im == 0.0);
auto m = exp(complex(double.nan, 1));
assert(m.re.isNaN && m.im.isNaN);
auto n = exp(complex(double.nan, double.nan));
assert(n.re.isNaN && n.im.isNaN);
}
@safe pure nothrow @nogc unittest
{
import std.math.constants : PI;
import std.math.operations : isClose;
auto a = exp(complex(0.0, -PI));
assert(isClose(a, -1.0, 0.0, 1e-15));
auto b = exp(complex(0.0, -2.0 * PI / 3.0));
assert(isClose(b, complex(-0.5L, -0.866025403784438646763L)));
auto c = exp(complex(0.0, PI / 3.0));
assert(isClose(c, complex(0.5L, 0.866025403784438646763L)));
auto d = exp(complex(0.0, 2.0 * PI / 3.0));
assert(isClose(d, complex(-0.5L, 0.866025403784438646763L)));
auto e = exp(complex(0.0, PI));
assert(isClose(e, -1.0, 0.0, 1e-15));
}
/**
* Calculate the natural logarithm of x.
* The branch cut is along the negative axis.
* Params:
* x = A complex number
* Returns:
* The complex natural logarithm of `x`
*
* $(TABLE_SV
* $(TR $(TH x) $(TH log(x)))
* $(TR $(TD (-0, +0)) $(TD (-$(INFIN), $(PI))))
* $(TR $(TD (+0, +0)) $(TD (-$(INFIN), +0)))
* $(TR $(TD (any, +$(INFIN))) $(TD (+$(INFIN), $(PI)/2)))
* $(TR $(TD (any, $(NAN))) $(TD ($(NAN), $(NAN))))
* $(TR $(TD (-$(INFIN), any)) $(TD (+$(INFIN), $(PI))))
* $(TR $(TD (+$(INFIN), any)) $(TD (+$(INFIN), +0)))
* $(TR $(TD (-$(INFIN), +$(INFIN))) $(TD (+$(INFIN), 3$(PI)/4)))
* $(TR $(TD (+$(INFIN), +$(INFIN))) $(TD (+$(INFIN), $(PI)/4)))
* $(TR $(TD ($(PLUSMN)$(INFIN), $(NAN))) $(TD (+$(INFIN), $(NAN))))
* $(TR $(TD ($(NAN), any)) $(TD ($(NAN), $(NAN))))
* $(TR $(TD ($(NAN), +$(INFIN))) $(TD (+$(INFIN), $(NAN))))
* $(TR $(TD ($(NAN), $(NAN))) $(TD ($(NAN), $(NAN))))
* )
*/
Complex!T log(T)(Complex!T x) @safe pure nothrow @nogc
{
static import std.math;
// Handle special cases explicitly here for better accuracy.
// The order here is important, so that the correct path is chosen.
if (std.math.isNaN(x.re))
{
if (std.math.isInfinity(x.im))
return Complex!T(T.infinity, T.nan);
else
return Complex!T(T.nan, T.nan);
}
if (std.math.isInfinity(x.re))
{
if (std.math.isNaN(x.im))
return Complex!T(T.infinity, T.nan);
else if (std.math.isInfinity(x.im))
{
if (std.math.signbit(x.re))
return Complex!T(T.infinity, std.math.copysign(3.0 * std.math.PI_4, x.im));
else
return Complex!T(T.infinity, std.math.copysign(std.math.PI_4, x.im));
}
else
{
if (std.math.signbit(x.re))
return Complex!T(T.infinity, std.math.copysign(std.math.PI, x.im));
else
return Complex!T(T.infinity, std.math.copysign(0.0, x.im));
}
}
if (std.math.isNaN(x.im))
return Complex!T(T.nan, T.nan);
if (std.math.isInfinity(x.im))
return Complex!T(T.infinity, std.math.copysign(std.math.PI_2, x.im));
if (x.re == 0.0 && x.im == 0.0)
{
if (std.math.signbit(x.re))
return Complex!T(-T.infinity, std.math.copysign(std.math.PI, x.im));
else
return Complex!T(-T.infinity, std.math.copysign(0.0, x.im));
}
return Complex!T(std.math.log(abs(x)), arg(x));
}
///
@safe pure nothrow @nogc unittest
{
import core.math : sqrt;
import std.math.constants : PI;
import std.math.operations : isClose;
auto a = complex(2.0, 1.0);
assert(log(conj(a)) == conj(log(a)));
auto b = 2.0 * log10(complex(0.0, 1.0));
auto c = 4.0 * log10(complex(sqrt(2.0) / 2, sqrt(2.0) / 2));
assert(isClose(b, c, 0.0, 1e-15));
assert(log(complex(-1.0L, 0.0L)) == complex(0.0L, PI));
assert(log(complex(-1.0L, -0.0L)) == complex(0.0L, -PI));
}
@safe pure nothrow @nogc unittest
{
import std.math.traits : isNaN, isInfinity;
import std.math.constants : PI, PI_2, PI_4;
auto a = log(complex(-0.0L, 0.0L));
assert(a == complex(-real.infinity, PI));
auto b = log(complex(0.0L, 0.0L));
assert(b == complex(-real.infinity, +0.0L));
auto c = log(complex(1.0L, real.infinity));
assert(c == complex(real.infinity, PI_2));
auto d = log(complex(1.0L, real.nan));
assert(d.re.isNaN && d.im.isNaN);
auto e = log(complex(-real.infinity, 1.0L));
assert(e == complex(real.infinity, PI));
auto f = log(complex(real.infinity, 1.0L));
assert(f == complex(real.infinity, 0.0L));
auto g = log(complex(-real.infinity, real.infinity));
assert(g == complex(real.infinity, 3.0 * PI_4));
auto h = log(complex(real.infinity, real.infinity));
assert(h == complex(real.infinity, PI_4));
auto i = log(complex(real.infinity, real.nan));
assert(i.re.isInfinity && i.im.isNaN);
auto j = log(complex(real.nan, 1.0L));
assert(j.re.isNaN && j.im.isNaN);
auto k = log(complex(real.nan, real.infinity));
assert(k.re.isInfinity && k.im.isNaN);
auto l = log(complex(real.nan, real.nan));
assert(l.re.isNaN && l.im.isNaN);
}
@safe pure nothrow @nogc unittest
{
import std.math.constants : PI;
import std.math.operations : isClose;
auto a = log(fromPolar(1.0, PI / 6.0));
assert(isClose(a, complex(0.0L, 0.523598775598298873077L), 0.0, 1e-15));
auto b = log(fromPolar(1.0, PI / 3.0));
assert(isClose(b, complex(0.0L, 1.04719755119659774615L), 0.0, 1e-15));
auto c = log(fromPolar(1.0, PI / 2.0));
assert(isClose(c, complex(0.0L, 1.57079632679489661923L), 0.0, 1e-15));
auto d = log(fromPolar(1.0, 2.0 * PI / 3.0));
assert(isClose(d, complex(0.0L, 2.09439510239319549230L), 0.0, 1e-15));
auto e = log(fromPolar(1.0, 5.0 * PI / 6.0));
assert(isClose(e, complex(0.0L, 2.61799387799149436538L), 0.0, 1e-15));
auto f = log(complex(-1.0L, 0.0L));
assert(isClose(f, complex(0.0L, PI), 0.0, 1e-15));
}
/**
* Calculate the base-10 logarithm of x.
* Params:
* x = A complex number
* Returns:
* The complex base 10 logarithm of `x`
*/
Complex!T log10(T)(Complex!T x) @safe pure nothrow @nogc
{
import std.math.constants : LN10;
return log(x) / Complex!T(LN10);
}
///
@safe pure nothrow @nogc unittest
{
import core.math : sqrt;
import std.math.constants : LN10, PI;
import std.math.operations : isClose;
auto a = complex(2.0, 1.0);
assert(log10(a) == log(a) / log(complex(10.0)));
auto b = log10(complex(0.0, 1.0)) * 2.0;
auto c = log10(complex(sqrt(2.0) / 2, sqrt(2.0) / 2)) * 4.0;
assert(isClose(b, c, 0.0, 1e-15));
}
@safe pure nothrow @nogc unittest
{
import std.math.constants : LN10, PI;
import std.math.operations : isClose;
auto a = log10(fromPolar(1.0, PI / 6.0));
assert(isClose(a, complex(0.0L, 0.227396058973640224580L), 0.0, 1e-15));
auto b = log10(fromPolar(1.0, PI / 3.0));
assert(isClose(b, complex(0.0L, 0.454792117947280449161L), 0.0, 1e-15));
auto c = log10(fromPolar(1.0, PI / 2.0));
assert(isClose(c, complex(0.0L, 0.682188176920920673742L), 0.0, 1e-15));
auto d = log10(fromPolar(1.0, 2.0 * PI / 3.0));
assert(isClose(d, complex(0.0L, 0.909584235894560898323L), 0.0, 1e-15));
auto e = log10(fromPolar(1.0, 5.0 * PI / 6.0));
assert(isClose(e, complex(0.0L, 1.13698029486820112290L), 0.0, 1e-15));
auto f = log10(complex(-1.0L, 0.0L));
assert(isClose(f, complex(0.0L, 1.36437635384184134748L), 0.0, 1e-15));
assert(ceqrel(log10(complex(-100.0L, 0.0L)), complex(2.0L, PI / LN10)) >= real.mant_dig - 1);
assert(ceqrel(log10(complex(-100.0L, -0.0L)), complex(2.0L, -PI / LN10)) >= real.mant_dig - 1);
}
/**
* Calculates x$(SUPERSCRIPT n).
* The branch cut is on the negative axis.
* Params:
* x = base
* n = exponent
* Returns:
* `x` raised to the power of `n`
*/
Complex!T pow(T, Int)(Complex!T x, const Int n) @safe pure nothrow @nogc
if (isIntegral!Int)
{
alias UInt = Unsigned!(Unqual!Int);
UInt m = (n < 0) ? -cast(UInt) n : n;
Complex!T y = (m % 2) ? x : Complex!T(1);
while (m >>= 1)
{
x *= x;
if (m % 2)
y *= x;
}
return (n < 0) ? Complex!T(1) / y : y;
}
///
@safe pure nothrow @nogc unittest
{
import std.math.operations : isClose;
auto a = complex(1.0, 2.0);
assert(pow(a, 2) == a * a);
assert(pow(a, 3) == a * a * a);
assert(pow(a, -2) == 1.0 / (a * a));
assert(isClose(pow(a, -3), 1.0 / (a * a * a)));
}
/// ditto
Complex!T pow(T)(Complex!T x, const T n) @trusted pure nothrow @nogc
{
static import std.math;
if (x == 0.0)
return Complex!T(0.0);
if (x.im == 0 && x.re > 0.0)
return Complex!T(std.math.pow(x.re, n));
Complex!T t = log(x);
return fromPolar!(T, T)(std.math.exp(n * t.re), n * t.im);
}
///
@safe pure nothrow @nogc unittest
{
import std.math.operations : isClose;
assert(pow(complex(0.0), 2.0) == complex(0.0));
assert(pow(complex(5.0), 2.0) == complex(25.0));
auto a = pow(complex(-1.0, 0.0), 0.5);
assert(isClose(a, complex(0.0, +1.0), 0.0, 1e-16));
auto b = pow(complex(-1.0, -0.0), 0.5);
assert(isClose(b, complex(0.0, -1.0), 0.0, 1e-16));
}
/// ditto
Complex!T pow(T)(Complex!T x, Complex!T y) @trusted pure nothrow @nogc
{
return (x == 0) ? Complex!T(0) : exp(y * log(x));
}
///
@safe pure nothrow @nogc unittest
{
import std.math.operations : isClose;
import std.math.exponential : exp;
import std.math.constants : PI;
auto a = complex(0.0);
auto b = complex(2.0);
assert(pow(a, b) == complex(0.0));
auto c = complex(0.0L, 1.0L);
assert(isClose(pow(c, c), exp((-PI) / 2)));
}
/// ditto
Complex!T pow(T)(const T x, Complex!T n) @trusted pure nothrow @nogc
{
static import std.math;
return (x > 0.0)
? fromPolar!(T, T)(std.math.pow(x, n.re), n.im * std.math.log(x))
: pow(Complex!T(x), n);
}
///
@safe pure nothrow @nogc unittest
{
import std.math.operations : isClose;
assert(pow(2.0, complex(0.0)) == complex(1.0));
assert(pow(2.0, complex(5.0)) == complex(32.0));
auto a = pow(-2.0, complex(-1.0));
assert(isClose(a, complex(-0.5), 0.0, 1e-16));
auto b = pow(-0.5, complex(-1.0));
assert(isClose(b, complex(-2.0), 0.0, 1e-15));
}
@safe pure nothrow @nogc unittest
{
import std.math.constants : PI;
import std.math.operations : isClose;
auto a = pow(complex(3.0, 4.0), 2);
assert(isClose(a, complex(-7.0, 24.0)));
auto b = pow(complex(3.0, 4.0), PI);
assert(ceqrel(b, complex(-152.91512205297134, 35.547499631917738)) >= double.mant_dig - 3);
auto c = pow(complex(3.0, 4.0), complex(-2.0, 1.0));
assert(ceqrel(c, complex(0.015351734187477306, -0.0038407695456661503)) >= double.mant_dig - 3);
auto d = pow(PI, complex(2.0, -1.0));
assert(ceqrel(d, complex(4.0790296880118296, -8.9872469554541869)) >= double.mant_dig - 1);
auto e = complex(2.0);
assert(ceqrel(pow(e, 3), exp(3 * log(e))) >= double.mant_dig - 1);
}
@safe pure nothrow @nogc unittest
{
import std.meta : AliasSeq;
import std.math : RealFormat, floatTraits;
static foreach (T; AliasSeq!(float, double, real))
{{
static if (floatTraits!T.realFormat == RealFormat.ibmExtended)
{
/* For IBM real, epsilon is too small (since 1.0 plus any double is
representable) to be able to expect results within epsilon * 100. */
}
else
{
T eps = T.epsilon * 100;
T a = -1.0;
T b = 0.5;
Complex!T ref1 = pow(complex(a), complex(b));
Complex!T res1 = pow(a, complex(b));
Complex!T res2 = pow(complex(a), b);
assert(abs(ref1 - res1) < eps);
assert(abs(ref1 - res2) < eps);
assert(abs(res1 - res2) < eps);
T c = -3.2;
T d = 1.4;
Complex!T ref2 = pow(complex(a), complex(b));
Complex!T res3 = pow(a, complex(b));
Complex!T res4 = pow(complex(a), b);
assert(abs(ref2 - res3) < eps);
assert(abs(ref2 - res4) < eps);
assert(abs(res3 - res4) < eps);
}
}}
}
@safe pure nothrow @nogc unittest
{
import std.meta : AliasSeq;
static foreach (T; AliasSeq!(float, double, real))
{{
auto c = Complex!T(123, 456);
auto n = c.toNative();
assert(c.re == n.re && c.im == n.im);
}}
}