Class Reference math.h

C mathematics for C++ macros. More...

Member

double	sin(double x)
double	cos(double x)
double	tan(double x)
double	asin(double x)
double	acos(double x)
double	atan(double x)
double	atan2(double y, double x)
double	sinh(double x)
double	cosh(double x)
double	tanh(double x)
double	exp(double x)
double	log(double x)
double	log10(double x)
double	pow(double x, double y)
double	sqrt(double x)
double	hypot(double x, double y)
double	floor(double x)
double	ceil(double x)
double	trunc(double x)
double	round(double x)
double	fabs(double x)
double	fmod(double x, double y)
double	fmin(double x, double y)
double	fmax(double x, double y)
int	isnan(double x)
int	isinf(double x)
int	isfinite(double x)
double	M_E
double	M_LOG2E
double	M_LOG10E
double	M_LN2
double	M_LN10
double	M_PI
double	M_PI_2
double	M_PI_4
double	M_SQRT2
double	M_SQRT1_2

Detailed Description

C mathematics for C++ macros. Load with #include <math.h> or #include <cmath> (same plugin). Available from LayoutEditor 20260918.

This is not the built-in math class. math::sin(x) works without an include. After this include you can also write free sin(x).

Angles are in radians, not degrees. A full circle is 2 * M_PI (about 6.2832). 90° is M_PI / 2. To convert: radians = degrees * M_PI / 180.0.

A double is a floating-point number (can have a decimal point). Integer abs is in stdlib.h. Use fabs here for double.

Example

#include <math.h>

int main(){
    double s = sin(M_PI / 2.0);   // 1.0
    double r = sqrt(4.0);         // 2.0
    cout("sin(pi/2) = ", s, "  sqrt(4) = ", r, "\n");
}

Python: import math (math.sin, math.pi). This include is for C++ macros only.

Member Function Documentation

double math.h::sin(double x)

Sine of an angle. On the unit circle this is the y-coordinate after rotating by x.

Parameters:

x (double) — angle in radians.

Returns: double in the range -1 … 1. sin(0) is 0, sin(M_PI / 2) is 1.

double math.h::cos(double x)

Cosine of an angle. On the unit circle this is the x-coordinate after rotating by x.

Parameters:

x (double) — angle in radians.

Returns: double in the range -1 … 1. cos(0) is 1, cos(M_PI / 2) is 0.

double math.h::tan(double x)

Tangent of an angle: sin(x) / cos(x). Undefined where cosine is zero (90°, 270°, …).

Parameters:

x (double) — angle in radians.

Returns: double. Grows without bound near M_PI / 2.

double math.h::asin(double x)

Inverse sine (arc sine): the angle whose sine is x.

Parameters:

x (double) — must be between -1 and 1 (otherwise the result is not a real number).

Returns: double angle in radians, in the range -π/2 … π/2.

double math.h::acos(double x)

Inverse cosine (arc cosine): the angle whose cosine is x.

Parameters:

x (double) — must be between -1 and 1.

Returns: double angle in radians, in the range 0 … π.

double math.h::atan(double x)

Inverse tangent of a ratio. It cannot tell the quadrant: atan(1) is 45° whether you are in the first or third quadrant. Prefer atan2 if you have both coordinates.

Parameters:

x (double) — the ratio y/x (or any real number).

Returns: double angle in radians, in the range -π/2 … π/2.

double math.h::atan2(double y, double x)

Four-quadrant inverse tangent. Give the y and x coordinates of a point; the function returns the angle of that point from the positive x-axis. Unlike atan, it uses the signs of both values, so it knows the quadrant.

Parameters:

y (double) — vertical coordinate (first argument, as in mathematics).
x (double) — horizontal coordinate.

Returns: double angle in radians, in the range -π … π. atan2(0, 1) is 0; atan2(1, 0) is M_PI / 2.

double math.h::sinh(double x)

Hyperbolic sine: (exp(x) - exp(-x)) / 2.

Parameters:

x (double) — real number (not an angle in the usual geometric sense).

Returns: double.

double math.h::cosh(double x)

Hyperbolic cosine: (exp(x) + exp(-x)) / 2. Always ≥ 1 for real x.

Parameters:

x (double).

Returns: double.

double math.h::tanh(double x)

Hyperbolic tangent: sinh(x) / cosh(x).

Parameters:

x (double).

Returns: double in the range -1 … 1.

double math.h::exp(double x)

Exponential function: e raised to the power x (e ≈ 2.71828, also M_E).

Parameters:

x (double) — the exponent.

Returns: double. exp(0) is 1, exp(1) is e.

double math.h::log(double x)

Natural logarithm (base e). Inverse of exp.

Parameters:

x (double) — must be greater than 0.

Returns: double. log(M_E) is 1, log(1) is 0.

double math.h::log10(double x)

Logarithm base 10. Useful for decades (orders of magnitude).

Parameters:

x (double) — must be greater than 0.

Returns: double. log10(100) is 2, log10(1e-3) is -3.

double math.h::pow(double x, double y)

Power: x raised to y (x^y).

Parameters:

x (double) — base.
y (double) — exponent.

Returns: double. pow(2, 10) is 1024, pow(9, 0.5) is 3. Negative bases with non-integer exponents can be invalid.

double math.h::sqrt(double x)

Square root of x.

Parameters:

x (double) — must be ≥ 0.

Returns: double ≥ 0. sqrt(0) is 0, sqrt(4) is 2.

double math.h::hypot(double x, double y)

Length of the hypotenuse of a right triangle with legs x and y: √(x² + y²). Safer than sqrt(x*x + y*y) for very large values (less overflow).

Parameters:

x (double) — first side.
y (double) — second side.

Returns: double ≥ 0. hypot(3, 4) is 5.

double math.h::floor(double x)

Largest integer that is not greater than x (rounds toward −∞).

Parameters:

x (double).

Returns: double (still a floating type, but the value is whole). floor(2.9) is 2, floor(-2.1) is -3.

double math.h::ceil(double x)

Smallest integer that is not smaller than x (rounds toward +∞).

Parameters:

x (double).

Returns: double. ceil(2.1) is 3, ceil(-2.9) is -2.

double math.h::trunc(double x)

Drops the fractional part (rounds toward 0).

Parameters:

x (double).

Returns: double. trunc(2.9) is 2, trunc(-2.9) is -2.

double math.h::round(double x)

Nearest integer. Halfway cases (2.5, -2.5) follow the C library on your platform (usually away from 0 or to even — do not rely on a specific halfway rule).

Parameters:

x (double).

Returns: double. round(2.2) is 2, round(2.8) is 3.

double math.h::fabs(double x)

Absolute value of a floating-point number (always ≥ 0).

Parameters:

x (double).

Returns: double. fabs(-3.5) is 3.5, fabs(3.5) is 3.5.

double math.h::fmod(double x, double y)

Floating-point remainder of x / y: the value r such that x = n*y + r with the same sign as x and |r| < |y|.

Parameters:

x (double) — dividend.
y (double) — divisor (must not be 0).

Returns: double. fmod(7.5, 2.0) is 1.5.

double math.h::fmin(double x, double y)

The smaller of two numbers.

Parameters:

x (double), y (double).

Returns: double — whichever is smaller.

double math.h::fmax(double x, double y)

The larger of two numbers.

Parameters:

x (double), y (double).

Returns: double — whichever is larger.

int math.h::isnan(double x)

Tests whether x is NaN (“not a number”, for example 0.0/0.0).

Parameters:

x (double).

Returns: non-zero (true) if x is NaN, otherwise 0.

int math.h::isinf(double x)

Tests whether x is infinite (+∞ or −∞).

Parameters:

x (double).

Returns: non-zero if infinite, otherwise 0.

int math.h::isfinite(double x)

Tests whether x is a normal finite number (not NaN and not infinite).

Parameters:

x (double).

Returns: non-zero if finite, otherwise 0.

double math.h::M_E

Returns: the named constant. e, base of natural logarithms Approximate value: 2.71828.

double math.h::M_LOG2E

Returns: the named constant. log₂(e) Approximate value: 1.44270.

double math.h::M_LOG10E

Returns: the named constant. log₁₀(e) Approximate value: 0.43429.

double math.h::M_LN2

Returns: the named constant. ln(2) Approximate value: 0.69315.

double math.h::M_LN10

Returns: the named constant. ln(10) Approximate value: 2.30259.

double math.h::M_PI

Returns: the named constant. π Approximate value: 3.14159.

double math.h::M_PI_2

Returns: the named constant. π/2 Approximate value: 1.57080.

double math.h::M_PI_4

Returns: the named constant. π/4 Approximate value: 0.78540.

double math.h::M_SQRT2

Returns: the named constant. √2 Approximate value: 1.41421.

double math.h::M_SQRT1_2

Returns: the named constant. 1/√2 Approximate value: 0.70711.