标准库头文件 <cmath>
来自 cppreference.com
这个头文件最初在 C 标准库中,名为 <math.h>.
这个头文件是 数值 库的一部分。
类型 | ||
float_t (C++11) |
至少与 float 一样宽的最高效浮点类型 (typedef) | |
double_t (C++11) |
至少与 double 一样宽的最高效浮点类型 (typedef) | |
宏 | ||
(C++11)(C++11) |
分别表示 float、double 和 long double 的溢出值 (宏常量) | |
(C++11) |
计算结果为正无穷大,或者保证会使 float 溢出的值 (宏常量) | |
(C++11) |
计算结果为类型为 float 的静默 NaN (宏常量) | |
(C++11)(C++11)(C++11) |
定义通用数学函数使用的错误处理机制 (宏常量) | |
分类 | ||
(C++11)(C++11)(C++11)(C++11)(C++11) |
表示浮点类别 (宏常量) | |
函数 | ||
基本运算 | ||
(C++11)(C++11) |
浮点值的绝对值 (|x|) (函数) | |
(C++11)(C++11) |
浮点除法运算的余数 (函数) | |
(C++11)(C++11)(C++11) |
除法运算的有符号余数 (函数) | |
(C++11)(C++11)(C++11) |
有符号余数以及除法运算的最后三位 (函数) | |
(C++11)(C++11)(C++11) |
融合乘加运算 (函数) | |
(C++11)(C++11)(C++11) |
两个浮点值中较大的一个 (函数) | |
(C++11)(C++11)(C++11) |
两个浮点值中较小的一个 (函数) | |
(C++11)(C++11)(C++11) |
两个浮点值的正差 (max(0, x-y)) (函数) | |
(C++11)(C++11)(C++11) |
非数字 (NaN) (函数) | |
线性插值 | ||
(C++20) |
线性插值函数 (函数) | |
指数函数 | ||
(C++11)(C++11) |
返回 e 的给定次幂 (ex) (函数) | |
(C++11)(C++11)(C++11) |
返回 2 的给定次幂 (2x) (函数) | |
(C++11)(C++11)(C++11) |
返回 e 的给定次幂减 1 (ex-1) (函数) | |
(C++11)(C++11) |
计算自然对数 (以 e 为底) (ln(x)) (函数) | |
(C++11)(C++11) |
计算常用对数 (以 10 为底) (log10(x)) (函数) | |
(C++11)(C++11)(C++11) |
给定数字的以 2 为底的对数 (log2(x)) (函数) | |
(C++11)(C++11)(C++11) |
给定数字加 1 的自然对数 (以 e 为底) (ln(1+x)) (函数) | |
幂函数 | ||
(C++11)(C++11) |
将一个数字提升到给定次幂 (xy) (函数) | |
(C++11)(C++11) |
计算平方根 (√x) (函数) | |
(C++11)(C++11)(C++11) |
计算立方根 (3√x) (函数) | |
(C++11)(C++11)(C++11) |
计算两个或三个(自 C++17 起)给定数字的平方和的平方根 (√x2 +y2 ), (√x2 +y2 +z2 )(自 C++17 起) (函数) | |
三角函数 | ||
(C++11)(C++11) |
计算正弦 (sin(x)) (函数) | |
(C++11)(C++11) |
计算余弦 (cos(x)) (函数) | |
(C++11)(C++11) |
计算正切 (tan(x)) (函数) | |
(C++11)(C++11) |
计算反正弦 (arcsin(x)) (函数) | |
(C++11)(C++11) |
计算反余弦 (arccos(x)) (函数) | |
(C++11)(C++11) |
计算反正切 (arctan(x)) (函数) | |
(C++11)(C++11) |
反正切,使用符号确定象限 (函数) | |
双曲函数 | ||
(C++11)(C++11) |
计算双曲正弦 (sinh(x)) (函数) | |
(C++11)(C++11) |
计算双曲余弦 (cosh(x)) (函数) | |
(C++11)(C++11) |
计算双曲正切 (tanh(x)) (函数) | |
(C++11)(C++11)(C++11) |
计算反双曲正弦 (arsinh(x)) (函数) | |
(C++11)(C++11)(C++11) |
计算反双曲余弦 (arcosh(x)) (函数) | |
(C++11)(C++11)(C++11) |
计算反双曲正切 (artanh(x)) (函数) | |
误差和伽马函数 | ||
(C++11)(C++11)(C++11) |
误差函数 (函数) | |
(C++11)(C++11)(C++11) |
余误差函数 (函数) | |
(C++11)(C++11)(C++11) |
伽马函数 (函数) | |
(C++11)(C++11)(C++11) |
伽马函数的自然对数 (函数) | |
最接近整数的浮点数运算 | ||
(C++11)(C++11) |
最接近且不小于给定值的整数 (函数) | |
(C++11)(C++11) |
最接近且不大于给定值的整数 (函数) | |
(C++11)(C++11)(C++11) |
最接近且大小不超过给定值的整数 (函数) | |
(C++11)(C++11)(C++11)(C++11)(C++11)(C++11)(C++11)(C++11)(C++11) |
最接近的整数,在半途情况中远离零舍入 (函数) | |
(C++11)(C++11)(C++11) |
使用当前舍入模式最接近的整数 (函数) | |
(C++11)(C++11)(C++11)(C++11)(C++11)(C++11)(C++11)(C++11)(C++11) |
使用当前舍入模式最接近的整数,如果结果不同则 抛出异常 (函数) | |
浮点数操作函数 | ||
(C++11)(C++11) |
将数字分解为有效数和以 2 为底的指数 (函数) | |
(C++11)(C++11) |
将数字乘以 2 的整数次方 (函数) | |
(C++11)(C++11) |
将数字分解为整数部分和小数部分 (函数) | |
(C++11)(C++11)(C++11)(C++11)(C++11)(C++11) |
将数字乘以 FLT_RADIX 的幂 (函数) | |
(C++11)(C++11)(C++11) |
提取数字的指数 (函数) | |
(C++11)(C++11)(C++11) |
提取数字的指数 (函数) | |
(C++11)(C++11)(C++11)(C++11)(C++11)(C++11) |
下一个可表示的浮点数,朝向给定值 (函数) | |
(C++11)(C++11)(C++11) |
复制浮点数的符号 (函数) | |
分类和比较 | ||
(C++11) |
对给定的浮点数进行分类 (函数) | |
(C++11) |
检查给定的数字是否为有限值 (函数) | |
(C++11) |
检查给定的数字是否为无穷大 (函数) | |
(C++11) |
检查给定的数字是否为 NaN (函数) | |
(C++11) |
检查给定的数字是否为正规数 (函数) | |
(C++11) |
检查给定的数字是否为负数 (函数) | |
(C++11) |
检查第一个浮点参数是否大于第二个 (函数) | |
(C++11) |
检查第一个浮点参数是否大于或等于第二个 (函数) | |
(C++11) |
检查第一个浮点参数是否小于第二个 (函数) | |
(C++11) |
检查第一个浮点参数是否小于或等于第二个 (函数) | |
(C++11) |
检查第一个浮点参数是否小于或大于第二个参数 (函数) | |
(C++11) |
检查两个浮点值是否无序 (函数) | |
数学特殊函数 | ||
(C++17)(C++17)(C++17) |
缔合拉盖尔多项式 (函数) | |
(C++17)(C++17)(C++17) |
缔合勒让德多项式 (函数) | |
(C++17)(C++17)(C++17) |
贝塔函数 (函数) | |
(C++17)(C++17)(C++17) |
(完全) 第一类椭圆积分 (函数) | |
(C++17)(C++17)(C++17) |
(完全) 第二类椭圆积分 (函数) | |
(C++17)(C++17)(C++17) |
(完全) 第三类椭圆积分 (函数) | |
(C++17)(C++17)(C++17) |
正则修正的圆柱贝塞尔函数 (函数) | |
(C++17)(C++17)(C++17) |
圆柱贝塞尔函数(第一类) (函数) | |
(C++17)(C++17)(C++17) |
非正则修正的圆柱贝塞尔函数 (函数) | |
(C++17)(C++17)(C++17) |
圆柱诺伊曼函数 (函数) | |
(C++17)(C++17)(C++17) |
(不完全) 第一类椭圆积分 (函数) | |
(C++17)(C++17)(C++17) |
(不完全) 第二类椭圆积分 (函数) | |
(C++17)(C++17)(C++17) |
(不完全) 第三类椭圆积分 (函数) | |
(C++17)(C++17)(C++17) |
指数积分 (函数) | |
(C++17)(C++17)(C++17) |
厄米特多项式 (函数) | |
(C++17)(C++17)(C++17) |
勒让德多项式 (函数) | |
(C++17)(C++17)(C++17) |
拉盖尔多项式 (函数) | |
(C++17)(C++17)(C++17) |
黎曼ζ函数 (函数) | |
(C++17)(C++17)(C++17) |
球面贝塞尔函数(第一类) (函数) | |
(C++17)(C++17)(C++17) |
球面缔合勒让德函数 (函数) | |
(C++17)(C++17)(C++17) |
球面诺伊曼函数 (函数) |
[编辑] 摘要
对于每个至少有一个类型为/* 浮点类型 */的参数的函数,提供针对每个 cv 无限定浮点类型的重载,其中函数签名中的所有 /* 浮点类型 */ 用该浮点类型替换。
对于每个至少有一个类型为 /* 浮点类型 */ 的参数的函数(除了 std::abs
),还提供额外的重载以确保,如果每个与 /* 浮点类型 */ 参数对应的参数都具有算术类型,那么每个此类参数将有效地转换为所有此类参数的类型中具有最大 浮点转换等级 和最大 浮点转换次等级 的浮点类型,其中整型参数被认为具有与 double 相同的浮点转换等级。如果没有这样的具有最大等级和次等级的浮点类型,那么重载解析不会从提供的重载中产生可用的候选。
namespace std { using float_t = /* see description */; using double_t = /* see description */; } #define HUGE_VAL /* see description */ #define HUGE_VALF /* see description */ #define HUGE_VALL /* see description */ #define INFINITY /* see description */ #define NAN /* see description */ #define FP_INFINITE /* see description */ #define FP_NAN /* see description */ #define FP_NORMAL /* see description */ #define FP_SUBNORMAL /* see description */ #define FP_ZERO /* see description */ #define FP_FAST_FMA /* see description */ #define FP_FAST_FMAF /* see description */ #define FP_FAST_FMAL /* see description */ #define FP_ILOGB0 /* see description */ #define FP_ILOGBNAN /* see description */ #define MATH_ERRNO /* see description */ #define MATH_ERREXCEPT /* see description */ #define math_errhandling /* see description */ namespace std { /* floating-point-type */ acos(/* floating-point-type */ x); float acosf(float x); long double acosl(long double x); /* floating-point-type */ asin(/* floating-point-type */ x); float asinf(float x); long double asinl(long double x); /* floating-point-type */ atan(/* floating-point-type */ x); float atanf(float x); long double atanl(long double x); /* floating-point-type */ atan2(/* floating-point-type */ y, /* floating-point-type */ x); float atan2f(float y, float x); long double atan2l(long double y, long double x); /* floating-point-type */ cos(/* floating-point-type */e x); float cosf(float x); long double cosl(long double x); /* floating-point-type */ sin(/* floating-point-type */ x); float sinf(float x); long double sinl(long double x); /* floating-point-type */ tan(/* floating-point-type */ x); float tanf(float x); long double tanl(long double x); /* floating-point-type */ acosh(/* floating-point-type */ x); float acoshf(float x); long double acoshl(long double x); /* floating-point-type */ asinh(/* floating-point-type */ x); float asinhf(float x); long double asinhl(long double x); /* floating-point-type */ atanh(/* floating-point-type */ x); float atanhf(float x); long double atanhl(long double x); /* floating-point-type */ cosh(/* floating-point-type */ x); float coshf(float x); long double coshl(long double x); /* floating-point-type */ sinh(/* floating-point-type */ x); float sinhf(float x); long double sinhl(long double x); /* floating-point-type */ tanh(/* floating-point-type */ x); float tanhf(float x); long double tanhl(long double x); /* floating-point-type */ exp(/* floating-point-type */ x); float expf(float x); long double expl(long double x); /* floating-point-type */ exp2(/* floating-point-type */ x); float exp2f(float x); long double exp2l(long double x); /* floating-point-type */ expm1(/* floating-point-type */ x); float expm1f(float x); long double expm1l(long double x); constexpr /* floating-point-type */ frexp(/* floating-point-type */ value, int* exp); constexpr float frexpf(float value, int* exp); constexpr long double frexpl(long double value, int* exp); constexpr int ilogb(/* floating-point-type */ x); constexpr int ilogbf(float x); constexpr int ilogbl(long double x); constexpr /* floating-point-type */ ldexp(/* floating-point-type */ x, int exp); constexpr float ldexpf(float x, int exp); constexpr long double ldexpl(long double x, int exp); /* floating-point-type */ log(/* floating-point-type */ x); float logf(float x); long double logl(long double x); /* floating-point-type */ log10(/* floating-point-type */ x); float log10f(float x); long double log10l(long double x); /* floating-point-type */ log1p(/* floating-point-type */ x); float log1pf(float x); long double log1pl(long double x); /* floating-point-type */ log2(/* floating-point-type */ x); float log2f(float x); long double log2l(long double x); constexpr /* floating-point-type */ logb(/* floating-point-type */ x); constexpr float logbf(float x); constexpr long double logbl(long double x); constexpr /* floating-point-type */ modf(/* floating-point-type */ value, /* floating-point-type */* iptr); constexpr float modff(float value, float* iptr); constexpr long double modfl(long double value, long double* iptr); constexpr /* floating-point-type */ scalbn(/* floating-point-type */ x, int n); constexpr float scalbnf(float x, int n); constexpr long double scalbnl(long double x, int n); constexpr /* floating-point-type */ scalbln(/* floating-point-type */ x, long int n); constexpr float scalblnf(float x, long int n); constexpr long double scalblnl(long double x, long int n); /* floating-point-type */ cbrt(/* floating-point-type */ x); float cbrtf(float x); long double cbrtl(long double x); // absolute values constexpr int abs(int j); // freestanding constexpr long int abs(long int j); // freestanding constexpr long long int abs(long long int j); // freestanding constexpr /* floating-point-type */ abs(/* floating-point-type */ j); // freestanding-deleted constexpr /* floating-point-type */ fabs(/* floating-point-type */ x); constexpr float fabsf(float x); constexpr long double fabsl(long double x); /* floating-point-type */ hypot(/* floating-point-type */ x, /* floating-point-type */ y); float hypotf(float x, float y); long double hypotl(long double x, long double y); // three-dimensional hypotenuse float hypot(/* floating-point-type */ x, /* floating-point-type */ y, /* floating-point-type */ z); /* floating-point-type */ pow(/* floating-point-type */ x, /* floating-point-type */ y); float powf(float x, float y); long double powl(long double x, long double y); /* floating-point-type */ sqrt(/* floating-point-type */ x); float sqrtf(float x); long double sqrtl(long double x); /* floating-point-type */ erf(/* floating-point-type */ x); float erff(float x); long double erfl(long double x); /* floating-point-type */ erfc(/* floating-point-type */ x); float erfcf(float x); long double erfcl(long double x); /* floating-point-type */ lgamma(/* floating-point-type */ x); float lgammaf(float x); long double lgammal(long double x); /* floating-point-type */ tgamma(/* floating-point-type */ x); float tgammaf(float x); long double tgammal(long double x); constexpr /* floating-point-type */ ceil(/* floating-point-type */ x); constexpr float ceilf(float x); constexpr long double ceill(long double x); constexpr /* floating-point-type */ floor(/* floating-point-type */ x); constexpr float floorf(float x); constexpr long double floorl(long double x); /* floating-point-type */ nearbyint(/* floating-point-type */ x); float nearbyintf(float x); long double nearbyintl(long double x); /* floating-point-type */ rint(/* floating-point-type */ x); float rintf(float x); long double rintl(long double x); long int lrint(/* floating-point-type */ x); long int lrintf(float x); long int lrintl(long double x); long long int llrint(/* floating-point-type */ x); long long int llrintf(float x); long long int llrintl(long double x); constexpr /* floating-point-type */ round(/* floating-point-type */ x); constexpr float roundf(float x); constexpr long double roundl(long double x); constexpr long int lround(/* floating-point-type */ x); constexpr long int lroundf(float x); constexpr long int lroundl(long double x); constexpr long long int llround(/* floating-point-type */ x); constexpr long long int llroundf(float x); constexpr long long int llroundl(long double x); constexpr /* floating-point-type */ trunc(/* floating-point-type */ x); constexpr float truncf(float x); constexpr long double truncl(long double x); constexpr /* floating-point-type */ fmod(/* floating-point-type */ x, /* floating-point-type */ y); constexpr float fmodf(float x, float y); constexpr long double fmodl(long double x, long double y); constexpr /* floating-point-type */ remainder(/* floating-point-type */ x, /* floating-point-type */ y); constexpr float remainderf(float x, float y); constexpr long double remainderl(long double x, long double y); constexpr /* floating-point-type */ remquo(/* floating-point-type */ x, /* floating-point-type */ y, int* quo); constexpr float remquof(float x, float y, int* quo); constexpr long double remquol(long double x, long double y, int* quo); constexpr /* floating-point-type */ copysign(/* floating-point-type */ x, /* floating-point-type */ y); constexpr float copysignf(float x, float y); constexpr long double copysignl(long double x, long double y); double nan(const char* tagp); float nanf(const char* tagp); long double nanl(const char* tagp); constexpr /* floating-point-type */ nextafter(/* floating-point-type */ x, /* floating-point-type */ y); constexpr float nextafterf(float x, float y); constexpr long double nextafterl(long double x, long double y); constexpr /* floating-point-type */ nexttoward(/* floating-point-type */ x, long double y); constexpr float nexttowardf(float x, long double y); constexpr long double nexttowardl(long double x, long double y); constexpr /* floating-point-type */ fdim(/* floating-point-type */ x, /* floating-point-type */ y); constexpr float fdimf(float x, float y); constexpr long double fdiml(long double x, long double y); constexpr /* floating-point-type */ fmax(/* floating-point-type */ x, /* floating-point-type */ y); constexpr float fmaxf(float x, float y); constexpr long double fmaxl(long double x, long double y); constexpr /* floating-point-type */ fmin(/* floating-point-type */ x, /* floating-point-type */ y); constexpr float fminf(float x, float y); constexpr long double fminl(long double x, long double y); constexpr /* floating-point-type */ fma(/* floating-point-type */ x, /* floating-point-type */ y, /* floating-point-type */ z); constexpr float fmaf(float x, float y, float z); constexpr long double fmal(long double x, long double y, long double z); // linear interpolation constexpr /* floating-point-type */ lerp(/* floating-point-type */ a, /* floating-point-type */ b, /* floating-point-type */ t) noexcept; // classification / comparison functions constexpr int fpclassify(/* floating-point-type */ x); constexpr bool isfinite(/* floating-point-type */ x); constexpr bool isinf(/* floating-point-type */ x); constexpr bool isnan(/* floating-point-type */ x); constexpr bool isnormal(/* floating-point-type */ x); constexpr bool signbit(/* floating-point-type */ x); constexpr bool isgreater(/* floating-point-type */ x, /* floating-point-type */ y); constexpr bool isgreaterequal(/* floating-point-type */ x, /* floating-point-type */ y); constexpr bool isless(/* floating-point-type */ x, /* floating-point-type */ y); constexpr bool islessequal(/* floating-point-type */ x, /* floating-point-type */ y); constexpr bool islessgreater(/* floating-point-type */ x, /* floating-point-type */ y); constexpr bool isunordered(/* floating-point-type */ x, /* floating-point-type */ y); // mathematical special functions // associated Laguerre polynomials /* floating-point-type */ assoc_laguerre(unsigned n, unsigned m, /* floating-point-type */ x); float assoc_laguerref(unsigned n, unsigned m, float x); long double assoc_laguerrel(unsigned n, unsigned m, long double x); // associated Legendre functions /* floating-point-type */ assoc_legendre(unsigned l, unsigned m, /* floating-point-type */ x); float assoc_legendref(unsigned l, unsigned m, float x); long double assoc_legendrel(unsigned l, unsigned m, long double x); // beta function /* floating-point-type */ beta(/* floating-point-type */ x, /* floating-point-type */ y); float betaf(float x, float y); long double betal(long double x, long double y); // complete elliptic integral of the first kind /* floating-point-type */ comp_ellint_1(/* floating-point-type */ k); float comp_ellint_1f(float k); long double comp_ellint_1l(long double k); // complete elliptic integral of the second kind /* floating-point-type */ comp_ellint_2(/* floating-point-type */ k); float comp_ellint_2f(float k); long double comp_ellint_2l(long double k); // complete elliptic integral of the third kind /* floating-point-type */ comp_ellint_3(/* floating-point-type */ k, /* floating-point-type */ nu); float comp_ellint_3f(float k, float nu); long double comp_ellint_3l(long double k, long double nu); // regular modified cylindrical Bessel functions /* floating-point-type */ cyl_bessel_i(/* floating-point-type */ nu, /* floating-point-type */ x); float cyl_bessel_if(float nu, float x); long double cyl_bessel_il(long double nu, long double x); // cylindrical Bessel functions of the first kind /* floating-point-type */ cyl_bessel_j(/* floating-point-type */ nu, /* floating-point-type */ x); float cyl_bessel_jf(float nu, float x); long double cyl_bessel_jl(long double nu, long double x); // irregular modified cylindrical Bessel functions /* floating-point-type */ cyl_bessel_k(/* floating-point-type */ nu, /* floating-point-type */ x); float cyl_bessel_kf(float nu, float x); long double cyl_bessel_kl(long double nu, long double x); // cylindrical Neumann functions; // cylindrical Bessel functions of the second kind /* floating-point-type */ cyl_neumann(/* floating-point-type */ nu, /* floating-point-type */ x); float cyl_neumannf(float nu, float x); long double cyl_neumannl(long double nu, long double x); // incomplete elliptic integral of the first kind /* floating-point-type */ ellint_1(/* floating-point-type */ k, /* floating-point-type */ phi); float ellint_1f(float k, float phi); long double ellint_1l(long double k, long double phi); // incomplete elliptic integral of the second kind /* floating-point-type */ ellint_2(/* floating-point-type */ k, /* floating-point-type */ phi); float ellint_2f(float k, float phi); long double ellint_2l(long double k, long double phi); // incomplete elliptic integral of the third kind /* floating-point-type */ ellint_3(/* floating-point-type */ k, /* floating-point-type */ nu, /* floating-point-type */ phi); float ellint_3f(float k, float nu, float phi); long double ellint_3l(long double k, long double nu, long double phi); // exponential integral /* floating-point-type */ expint(/* floating-point-type */ x); float expintf(float x); long double expintl(long double x); // Hermite polynomials /* floating-point-type */ hermite(unsigned n, /* floating-point-type */ x); float hermitef(unsigned n, float x); long double hermitel(unsigned n, long double x); // Laguerre polynomials /* floating-point-type */ laguerre(unsigned n, /* floating-point-type */ x); float laguerref(unsigned n, float x); long double laguerrel(unsigned n, long double x); // Legendre polynomials /* floating-point-type */ legendre(unsigned l, /* floating-point-type */ x); float legendref(unsigned l, float x); long double legendrel(unsigned l, long double x); // Riemann zeta function /* floating-point-type */ riemann_zeta(/* floating-point-type */ x); float riemann_zetaf(float x); long double riemann_zetal(long double x); // spherical Bessel functions of the first kind /* floating-point-type */ sph_bessel(unsigned n, /* floating-point-type */ x); float sph_besself(unsigned n, float x); long double sph_bessell(unsigned n, long double x); // spherical associated Legendre functions /* floating-point-type */ sph_legendre(unsigned l, unsigned m, /* floating-point-type */ theta); float sph_legendref(unsigned l, unsigned m, float theta); long double sph_legendrel(unsigned l, unsigned m, long double theta); // spherical Neumann functions; // spherical Bessel functions of the second kind /* floating-point-type */ sph_neumann(unsigned n, /* floating-point-type */ x); float sph_neumannf(unsigned n, float x); long double sph_neumannl(unsigned n, long double x); }