v?abs

Compute the absolute value or modulus of the input vector.

Interface Definition

C interface:

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

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

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

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

Parameters

Parameter	Type	Description	Input/Output
len	Integer	Number of elements in the input vector. If len ≤ 0, an invalid parameter error is reported and the function returns.	Input
src	Single-precision floating-point type for vsabs Double-precision floating-point type for vdabs Single-precision floating-point complex type for vcabs Double-precision floating-point complex type for vzabs	Input vector src with length len. If the pointer is null, a null pointer error is reported and the function returns.	Input
dst	Single-precision floating-point type for vsabs Double-precision floating-point type for vdabs Single-precision floating-point type for vcabs Double-precision floating-point type for vzabs	Output vector dst with length len. If the pointer is null, a null pointer error is reported and the function returns.	Output

Parameter

Type

Description

Input/Output

len

Integer

Number of elements in the input vector.

If len ≤ 0, an invalid parameter error is reported and the function returns.

Input

src

Single-precision floating-point type for vsabs
Double-precision floating-point type for vdabs
Single-precision floating-point complex type for vcabs
Double-precision floating-point complex type for vzabs

Input vector src with length len.

If the pointer is null, a null pointer error is reported and the function returns.

Input

dst

Single-precision floating-point type for vsabs
Double-precision floating-point type for vdabs
Single-precision floating-point type for vcabs
Double-precision floating-point type for vzabs

Output vector dst with length len.

If the pointer is null, a null pointer error is reported and the function returns.

Output

Return Value

For vsabs and vdabs, the absolute value of the real number is returned. For vcabs and vzabs, the modulus of the complex number is returned. That is, given and $\text{[math]}$ , obtain $\text{[math]}$ .

For vsabs and vdabs, special output values are listed in the following table.

Input Value (src)	Output Value (dst)
+inf	+inf
-inf	+inf
nan	nan

For vcabs and vzabs, special output values are listed in the following table.

Real Part of the Input (src->real)	Imaginary Part of the Input (src->imag)	Output Value (dst)
snan	any	nan
any	snan	nan
±inf	!=snan	inf
!=snan	±inf	inf
qnan	\|srcImag\| < inf	nan
\|srcReal\| < inf	qnan	nan
$\text{[math]}$		inf

Dependencies

C: "kvml.h"

Examples

C interface:

       
                #define N 4
    const float src[N] = {-1.4f, 27.8f, -INFINITY, NAN};
    float dst[N] = {0};

    vsabs(N, src, dst);
    printFArr("input :", N, src);
    printFArr("output:", N, dst);
 
    /** 
     *  input :  -1.400   27.800     -inf      nan 
     *  output:   1.400   27.800      inf      nan
     * 
     */

Parent topic: Function Syntax