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sinpi

Compute the sine of the input real number multiplied by π.

Interface Definition

C interface:

float sinpif(float x);

double sinpi(double x);

Parameters

Parameter

Type

Description

Input/Output

x
  • For sinpif, x is of single-precision floating-point type.
  • For sinpi, x is of double-precision floating-point type.

Floating-point value of the input data.

Input

Return Value

  • The sine y of the input x multiplied by π is returned, that is, y = sin(x * π). y ∈ [-1, +1]
  • If the input is +0, the return value is +0.
  • If the input is –0, the return value is –0.
  • If the input is ±∞, the return value is NaN.
  • If the input is NaN, the return value is NaN.

Dependency

C: "km.h"

Example

C interface:
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    // 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
     * 
     * */
Parent topic: Function Syntax