Norm

Calculates the L1 norm, L2 norm, or ∞ (Inf) norm of a vector. The formula is as follows:

L1 norm:
L2 norm:
∞ norm

The function interface declaration is as follows:

L1 norm:
HmppResult HMPPS_Norm_L1_32f(const float* src, int32_t len, float* norm);

HmppResult HMPPS_Norm_L1_64f(const double* src, int32_t len, double* norm);

HmppResult HMPPS_Norm_L1_16s32f(const int16_t* src, int32_t len, float* norm);

HmppResult HMPPS_Norm_L1_32fc64f(const Hmpp32fc* src, int32_t len, double* norm);

HmppResult HMPPS_Norm_L1_64fc64f(const Hmpp64fc* src, int32_t len, double* norm);
L1 norm with scaling:
HmppResult HMPPS_Norm_L1_16s32s_S(const int16_t* src, int32_t len, int32_t* norm, double scale);

HmppResult HMPPS_Norm_L1_16s64s_S(const int16_t* src, int32_t len, int64_t* norm, double scale);
L2 norm:
HmppResult HMPPS_Norm_L2_32f(const float* src, int32_t len, float* norm);

HmppResult HMPPS_Norm_L2_64f(const double* src, int32_t len, double* norm);

HmppResult HMPPS_Norm_L2_16s32f(const int16_t* src, int32_t len, float* norm);

HmppResult HMPPS_Norm_L2_32fc64f(const Hmpp32fc* src, int32_t len, double* norm);

HmppResult HMPPS_Norm_L2_64fc64f(const Hmpp64fc* src, int32_t len, double* norm);
L2 norm with scaling:
HmppResult HMPPS_Norm_L2_16s32s_S(const int16_t* src, int32_t len, int32_t* norm, double scale);
L2Sqr norm:
HmppResult HMPPS_Norm_L2Sqr_16s64s_S(const int16_t* src, int32_t len, int64_t* norm, double scale);
Infinity norm:
HmppResult HMPPS_Norm_Inf_32f(const float* src, int32_t len, float* norm);

HmppResult HMPPS_Norm_Inf_64f(const double* src, int32_t len, double* norm);

HmppResult HMPPS_Norm_Inf_16s32f(const int16_t* src, int32_t len, float* norm);

HmppResult HMPPS_Norm_Inf_32fc32f(const Hmpp32fc* src, int32_t len, float* norm);

HmppResult HMPPS_Norm_Inf_64fc64f(const Hmpp64fc* src, int32_t len, double* norm);
Infinity norm with scaling:
HmppResult HMPPS_Norm_Inf_16s32s_S(const int16_t* src, int32_t len, int32_t* norm, double scale);

Parameters

Parameter	Description	Value Range	Input/Output
src	Pointer to the source vector	The value cannot be NULL.	Input
len	Vector length	(0, INT_MAX]	Input
norm	Pointer to the norm	The value cannot be NULL.	Output
scale	Scale factor	scale = 2^n, where n is an integer. The value is within (0, INF).	Input

Return Value

Success: HMPP_STS_NO_ERR
Failure: An error code is returned.

Error Code

Error Code	Description
HMPP_STS_NULL_PTR_ERR	The value of src or norm is NULL.
HMPP_STS_SIZE_ERR	The value of len is less than or equal to 0.
HMPP_STS_SCALE_ERR	The value of scale is not within the range (0, INF) or is NaN.

Example

#define BUFFER_SIZE_T 10

void NormExample(void)
{
    float[BUFFER_SIZE_T] = {3, 0, 2, -8, 3, 1, 7, 5, -2, 1};
    float norm1[1];
    float norm2[1];
    float norm3[1];
    HmppResult sign1, sign2, sign3;
    sign1 = HMPPS_Norm_Inf_32f(src, BUFFER_SIZE_T, norm1);
    printf("NormInf: result = %d\n", sign1);
    if (sign1 != HMPP_STS_NO_ERR) {
        return;
    }
    printf("Inf = %.2f\n", norm1[0]);
    sign2 = HMPPS_Norm_L1_32f(src, BUFFER_SIZE_T, norm2);
    printf("NormL1: result = %d\n", sign2);
    if (sign2 != HMPP_STS_NO_ERR) {
        return;
    }
    printf("L1 = %.2f\n", norm2[0]);
    sign3 = HMPPS_Norm_L2_32f(src, BUFFER_SIZE_T, norm3);
    printf("NormL2: result = %d\n", sign3);
    if (sign3 != HMPP_STS_NO_ERR) {
        return;
    }
    printf("L2 = %.2f\n", norm3[0]);
    printf("\n");
}

Output:

NormInf: result = 0
Inf = 8.00
NormL1: result = 0
L1 = 32.00
NormL2: result = 0
L2 = 12.88

Parent topic: Basic and Common Calculations