v?pow

Compute a vector raised to a specified power element-wise. The specified power and result are also vectors.

Interface Definition

C interface:

void vspow(const int len, const float* src1, const float* src2, float* dst);

void vdpow(const int len, const double* src1, const double* src2, double* dst);

Fortran interface:

CALL VSPOW(LEN, SRC1, SRC2, DST);

CALL VDPOW(LEN, SRC1, SRC2, 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
src1	For vspow, src1 is of the single-precision floating-point type. For vdpow, src1 is of the double-precision floating-point type.	Input vector src1 with length len. If the pointer is null, the system prompts a null pointer error.	Input
src2	For vspow, src2 is of the single-precision floating-point type. For vdpow, src2 is of the double-precision floating-point type.	Input vector src2 with length len. If the pointer is null, the system prompts a null pointer error.	Input
dst	For vspow, dst is of the single-precision floating-point type. For vdpow, dst is of the double-precision floating-point type.	Output vector dst with length len. If the pointer is null, the system prompts a null pointer error.	Output

Return Value

If the value of src1 is greater than 0 and the value of src2 is a decimal, the value range of dst is ∈ (-INF, +INF).
If the value of src1 is -0 and the value of src2 is a negative odd number, then the value of dst is -∞. If the value of src1 is ±0 and the value of src2 is a negative number, then the value of dst is +∞.
If the value of src1 is ±0 and the value of src2 is a positive odd number, then the value of dst is ±0. If the value of src1 is ±0 and the value of src2 is a positive number, then the value of dst is +0.
If the value of src1 is ±1 and the value of src2 is any value, the value of dst is +1.
If the value of src1 is any value and the value of src2 is ±0, the value of dst is +1.
If the value of src1 is less than +0 and the value of src2 is a decimal, the value of dst is NaN.
If the value of src1 is less than 1 and the value of src2 is -∞, then the value of dst is +∞. If the value of src1 is greater than 1 and the value of src2 is -∞, then the value of dst is +0.
If the value of src1 is less than 1 and the value of src2 is +∞, then the value of dst is +0. If the value of src1 is greater than 1 and the value of src2 is +∞, then the value of dst is +∞.
If the value of src1 is -∞ and the value of src2 is a negative odd number, then the value of dst is -0. If the value of src1 is -∞ and the value of src2 is a negative number, then the value of dst is +0.
If the value of src1 is -∞ and the value of src2 is a positive odd number, then the value of dst is -∞. If the value of src1 is -∞ and the value of src2 is a positive number, then the value of dst is +∞.
If the value of src1 is +∞ and the value of src2 is less than +0, the value of dst is +0. If the value of src1 is +∞ and the value of src2 is greater than or equal to +0, the value of dst is +∞.
If the values of src1 and src2 are both large finite numbers, the value of dst is ±∞.
If the values of src1 and src2 are both NaN, the value of dst is NaN.

Dependencies

C: "kvml.h"

Fortran: "kvml.f03"

Examples

C interface:

    int i, len = 4; 
    float src1[len] = [1.0f, 0.0f, 16.0f, 2.0f]; 
    float src2[len] = [0.0f, 0.0f, 0.5f, 3.0f]; 
    float* dst = (float*)malloc(sizeof(float) * len); 
    if (dst == NULL) { 
        printf("Malloc Failed!\n"); 
        return 0; 
    } 
    vspow(len, src1, src2, dst); 
    /** 
     *  Output dst: 
     *     1.0  1.0  4.0  8.0 
     * 
     */

Fortran interface:

    INTEGER :: LEN = 4 
    REAL(4) SRC1(4)  
    REAL(4) SRC2(4) 
    REAL(4) DST(4) 
    DATA SRC1 /1.2, 2.5, 2.4, 3.6/ 
    DATA SRC2 /8.6, -2.5, 1.7, 1.3/ 
    CALL VSPOW(LEN, SRC1, SRC2, DST) 
    !  
    ! OUTPUT DST: 
    !     4.79688072, 0.101192884, 4.42954540, 5.28680420 
    !

Parent topic: KML_VML Library Functions