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v?log2

Compute the base-2 logarithm of a vector.

Interface Definition

C interface:

void vslog2(const int len, const float* src, float* dst);

void vdlog2(const int len, const double* src, double* dst);

Parameter

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 vslog2
  • Double-precision floating-point type for vdlog2

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 vslog2
  • Double-precision floating-point type for vdlog2

Output vector dst with length len.

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

Output

Return Value

Return the result of . For special values, see the following table.

Input Value (src)

Output Value (dst)

±0

-inf

<0

nan

+inf

+inf

nan

nan

Dependency

C: "kvml.h"

Example

C interface:

    #define N 4
    const float src[N] = {2.2f, 1.0f, +INFINITY, -3.0f};
    float dst[N] = {0};

    vslog2(N, src, dst);
    printFArr("input1:", N, src);
    printFArr("output:", N, dst);

    /** 
     *  input1:   2.200    1.000      inf   -3.000
     *  output:   1.138    0.000      inf      nan 
     * 
     */
Parent topic: Function Syntax