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v?asinpi

Interface Definition

C interface:

void vsasinpi(const int len, const float* src, float* dst);

void vdasinpi(const int len, const double* src, double* dst);

Parameters

Parameter

Type

Description

Input/Output

len

Integer

Number of elements in the input vector.

If len ≤ 0, the system displays a message indicating that the value of len is invalid.

Input

src

  • Single-precision floating-point type for vsasinpi
  • Double-precision floating-point type for vdasinpi

Input vector src with length len.

If the pointer is null, the system prompts a null pointer error.

Input

dst

  • Single-precision floating-point type for vsasinpi
  • Double-precision floating-point type for vdasinpi

Output vector dst with length len.

If the pointer is null, the system prompts a null pointer error.

Output

Return Value

  • Each operation value returns the arcsine of x divided by π, that is, y = asin(x)/π. y ∈ [-0.5, +0.5]
  • For special values, see the following table.

    Input Value (src)

    Output Value (dst)

    1

    0.5

    -1

    -0.5

    |x| > 1

    nan

    ±inf

    nan

    nan

    nan

Dependency

C: "kvml.h"

Example

C interface:

    int i, len = 8; 
    float src[8] = {-1.0f, -0.5f, 0.0f, 0.5f, 1.0f, 2.0f, INFINITY, NAN}; 
    float* dst = (float*)malloc(sizeof(float) * len); 
    if (dst == NULL) { 
        printf("Malloc Failed!\n"); 
        return 0; 
    } 
    vsasinpi(len, src, dst);

    /** 
     *  Output dst: 
     *     -0.500000 -0.166667 0.000000 0.166667 0.500000 nan nan nan
     */