sin
计算实数的正弦值。
接口定义
C interface:
float sinf(float x);
double sin(double x);
float complex csinf(float complex x);
double complex csin(double complex x);
Fortran interface:
RES = SINF(X);
RES = SIN(X);
RES = CSINF(X);
RES = CSIN(X);
参数
参数名 |
类型 |
描述 |
输入/输出 |
|---|---|---|---|
x |
|
表示弧度角的浮点值。 |
输入 |
返回值
- 返回弧度角x的正弦函数值y,y ∈ [-1, +1]。
- 输入+0,返回+0。
- 输入-0,返回-0。
- 输入±∞,返回nan。
- 输入nan,返回nan。
依赖
C: "km.h"
Fortran: "km.f03"
示例
C interface:
double pi = acos(-1);
// typical usage
double a = pi/6, b = 1.0, c = -3*pi/4, d = pi/3;
// special handling
double e = INFINITY, f = -INFINITY, g = NAN;
double complex k = 0 + 0 * I;
// print result
printf("sin(pi/6) = %.15f\n", sin(a));
printf("sin(1.0) = %.15f\n", sin(b));
printf("sin(-3*pi/4) = %.15f\n", sin(c));
printf("sin(pi/3) = %.15f\n", sin(d));
printf("sin(INFINITY) = %.15f\n", sin(e));
printf("sin(-INFINITY) = %.15f\n", sin(f));
printf("sin(NAN) = %.15f\n", sin(g));
printf("csin(0+0*I) = %.15f + %.15f * I\n", creal(csin(k)), cimag(csin(k)));
/*
* sin(pi/6) = 0.500000000000000
* sin(1.0) = 0.841470984807897
* sin(-3*pi/4) = -0.707106781186548
* sin(pi/3) = 0.866025403784438
* sin(INFINITY) = nan
* sin(-INFINITY) = nan
* sin(NAN) = nan
* csin(0+0*I) = 0 + 0 * I
*
* */
Fortran interface:
REAL(8) :: X = 1.0
PRINT*, SIN(X)
!
! OUTPUT
! 0.841470984807897
!
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