std.complex

pure nothrow @nogc @safe auto complex(R)(const R re)
if (is(R : double));

pure nothrow @nogc @safe auto complex(R, I)(const R re, const I im)
if (is(R : double) && is(I : double));

Helper function that returns a complex number with the specified real and imaginary parts.

Parameters:

R	(template parameter) type of real part of complex number
I	(template parameter) type of imaginary part of complex number
R re	real part of complex number to be constructed
I 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 std.traits.CommonType!(R, I).

Examples:

auto a = complex(1.0);
static assert(is(typeof(a) == Complex!double));
writeln(a.re); // 1.0
writeln(a.im); // 0.0

auto b = complex(2.0L);
static assert(is(typeof(b) == Complex!real));
writeln(b.re); // 2.0L
writeln(b.im); // 0.0L

auto c = complex(1.0, 2.0);
static assert(is(typeof(c) == Complex!double));
writeln(c.re); // 1.0
writeln(c.im); // 2.0

auto d = complex(3.0, 4.0L);
static assert(is(typeof(d) == Complex!real));
writeln(d.re); // 3.0
writeln(d.im); // 4.0L

auto e = complex(1);
static assert(is(typeof(e) == Complex!double));
writeln(e.re); // 1
writeln(e.im); // 0

auto f = complex(1L, 2);
static assert(is(typeof(f) == Complex!double));
writeln(f.re); // 1L
writeln(f.im); // 2

auto g = complex(3, 4.0L);
static assert(is(typeof(g) == Complex!real));
writeln(g.re); // 3
writeln(g.im); // 4.0L

struct Complex(T) if (isFloatingPoint!T);

A complex number parametrised by a type T, which must be either float, double or real.

T re;

The real part of the number.

T im;

The imaginary part of the number.

const @safe string toString();

const void toString(Writer, Char)(scope Writer w, ref scope const FormatSpec!Char formatSpec)
if (isOutputRange!(Writer, const(Char)[]));

Converts the complex number to a string representation.

The second form of this function is usually not called directly; instead, it is used via std.string.format, as shown in the examples below. Supported format characters are 'e', 'f', 'g', 'a', and 's'.

See the std.format and std.string.format documentation for more information.

Examples:

auto c = complex(1.2, 3.4);

// Vanilla toString formatting:
writeln(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;
writeln(format("%.2f", c)); // "1.20+3.40i"
writeln(format("%4.1f", c)); // " 1.2+ 3.4i"

this(R : T)(Complex!R z);

this(Rx : T, Ry : T)(const Rx x, const Ry y);

this(R : T)(const R r);

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.

pure nothrow @nogc @safe T abs(T)(Complex!T z);

Parameters:

Complex!T z

A complex number.

Returns:

The absolute value (or modulus) of z.

Examples:

static import std.math;
writeln(abs(complex(1.0))); // 1.0
writeln(abs(complex(0.0, 1.0))); // 1.0
writeln(abs(complex(1.0L, -2.0L))); // std.math.sqrt(5.0L)

pure nothrow @nogc @safe T sqAbs(T)(Complex!T z);

pure nothrow @nogc @safe T sqAbs(T)(const T x)
if (isFloatingPoint!T);

Parameters:

Complex!T z	A complex number.
T x	A real number.

Returns:

The squared modulus of z. For genericity, if called on a real number, returns its square.

Examples:

import std.math;
writeln(sqAbs(complex(0.0))); // 0.0
writeln(sqAbs(complex(1.0))); // 1.0
writeln(sqAbs(complex(0.0, 1.0))); // 1.0
assert(approxEqual(sqAbs(complex(1.0L, -2.0L)), 5.0L));
assert(approxEqual(sqAbs(complex(-3.0L, 1.0L)), 10.0L));
assert(approxEqual(sqAbs(complex(1.0f,-1.0f)), 2.0f));

pure nothrow @nogc @safe T arg(T)(Complex!T z);

Parameters:

Complex!T z

A complex number.

Returns:

The argument (or phase) of z.

Examples:

import std.math;
writeln(arg(complex(1.0))); // 0.0
writeln(arg(complex(0.0L, 1.0L))); // PI_2
writeln(arg(complex(1.0L, 1.0L))); // PI_4

pure nothrow @nogc @safe Complex!T conj(T)(Complex!T z);

Parameters:

Complex!T z

A complex number.

Returns:

The complex conjugate of z.

Examples:

writeln(conj(complex(1.0))); // complex(1.0)
writeln(conj(complex(1.0, 2.0))); // complex(1.0, -2.0)

pure nothrow @nogc @safe Complex!(CommonType!(T, U)) fromPolar(T, U)(const T modulus, const U argument);

Constructs a complex number given its absolute value and argument.

Parameters:

T modulus	The modulus
U argument	The argument

Returns:

The complex number with the given modulus and argument.

Examples:

import std.math;
auto z = fromPolar(std.math.sqrt(2.0), PI_4);
assert(approxEqual(z.re, 1.0L, real.epsilon));
assert(approxEqual(z.im, 1.0L, real.epsilon));

pure nothrow @nogc @safe Complex!T sin(T)(Complex!T z);

pure nothrow @nogc @safe Complex!T cos(T)(Complex!T z);

Trigonometric functions on complex numbers.

Parameters:

Complex!T z

A complex number.

Returns:

The sine and cosine of z, respectively.

Examples:

static import std.math;
writeln(sin(complex(0.0))); // 0.0
writeln(sin(complex(2.0L, 0))); // std.math.sin(2.0L)

Examples:

import std.complex;
writeln(cos(complex(0.0))); // 1.0

pure nothrow @nogc @trusted Complex!real expi(real y);

Parameters:

real 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.

Examples:

import std.math : cos, sin;
writeln(expi(0.0L)); // 1.0L
writeln(expi(1.3e5L)); // complex(cos(1.3e5L), sin(1.3e5L))

pure nothrow @nogc @safe Complex!real coshisinh(real y);

Parameters:

real 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.

Examples:

import std.math : cosh, sinh;
writeln(coshisinh(3.0L)); // complex(cosh(3.0L), sinh(3.0L))

pure nothrow @nogc @safe Complex!T sqrt(T)(Complex!T z);

Parameters:

Complex!T z

A complex number.

Returns:

The square root of z.

Examples:

static import std.math;
writeln(sqrt(complex(0.0))); // 0.0
writeln(sqrt(complex(1.0L, 0))); // std.math.sqrt(1.0L)
writeln(sqrt(complex(-1.0L, 0))); // complex(0, 1.0L)
writeln(sqrt(complex(-8.0, -6.0))); // complex(1.0, -3.0)