---
title: sinpi
description: "计算输入实数与π相乘的正弦值。"
url: https://www.hikunpeng.com/document/detail/zh/kunpenghpcs/hpckit/devg/kunpengaccel_kml_0148.html
sourcePath: /source/zh/kunpenghpcs/hpckit/devg/kunpengaccel_kml_0148.html
indexId: 551b53302715c1aa39331ab1d32b53f3ba926a1ffe67c7017a686dce7384c8e261
---
# sinpi

计算输入实数与π相乘的正弦值。

#### 接口定义

C interface：

float sinpif(float x);

double sinpi(double x);


#### 参数

| 参数名 | 类型 | 描述 | 输入/输出 |
| --- | --- | --- | --- |
| x | 在sinpif中，x是单精度浮点类型。 在sinpi中，x是双精度浮点类型。 | 表示输入数据的浮点值。 | 输入 |


#### 返回值

- 返回x乘以π的正弦函数值y=sin(x * π)，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"


#### 示例

C interface：```
// print result
    printf("sinpi(0.0) = %.15f\n", sinpi(0.0));
    printf("sinpi(-0.0) = %.15f\n", sinpi(-0.0));
    printf("sinpi(0.25) = %.15f\n", sinpi(0.25));
    printf("sinpi(-0.25) = %.15f\n", sinpi(-0.25));
    printf("sinpi(0.5) = %.15f\n", sinpi(0.5));
    printf("sinpi(-0.5) = %.15f\n", sinpi(-0.5));
    printf("sinpi(1.0) = %.15f\n", sinpi(1.0));
    printf("sinpi(-1.0) = %.15f\n", sinpi(-1.0));
    printf("sinpi(2.0) = %.15f\n", sinpi(2.0));
    printf("sinpi(-2.0) = %.15f\n", sinpi(-2.0));
    printf("sinpi(INFINITY) = %.15f\n", sinpi(INFINITY));
    printf("sinpi(-INFINITY) = %.15f\n", sinpi(-INFINITY));
    printf("sinpi(NAN) = %.15f\n", sinpi(NAN));
    printf("sinpi(-NAN) = %.15f\n", sinpi(-NAN));
    /* 
     * 
     * sinpi(0.0) = 0.000000000000000
     * sinpi(-0.0) = -0.000000000000000
     * sinpi(0.25) = 0.707106781186548
     * sinpi(-0.25) = -0.707106781186548
     * sinpi(0.5) = 1.000000000000000
     * sinpi(-0.5) = -1.000000000000000
     * sinpi(1.0) = 0.000000000000000
     * sinpi(-1.0) = -0.000000000000000
     * sinpi(2.0) = 0.000000000000000
     * sinpi(-2.0) = -0.000000000000000
     * sinpi(INFINITY) = nan
     * sinpi(-INFINITY) = nan
     * sinpi(NAN) = nan
     * sinpi(-NAN) = -nan
     * 
     * */
```