NMSIS-DSP  Version 1.2.0
NMSIS DSP Software Library

Calculates the sum of the squares of the elements in the input vector. The underlying algorithm is used: More...

Functions

void riscv_power_f16 (const float16_t *pSrc, uint32_t blockSize, float16_t *pResult)
 Sum of the squares of the elements of a floating-point vector. More...
 
void riscv_power_f32 (const float32_t *pSrc, uint32_t blockSize, float32_t *pResult)
 Sum of the squares of the elements of a floating-point vector. More...
 
void riscv_power_f64 (const float64_t *pSrc, uint32_t blockSize, float64_t *pResult)
 Sum of the squares of the elements of a floating-point vector. More...
 
void riscv_power_q15 (const q15_t *pSrc, uint32_t blockSize, q63_t *pResult)
 Sum of the squares of the elements of a Q15 vector. More...
 
void riscv_power_q31 (const q31_t *pSrc, uint32_t blockSize, q63_t *pResult)
 Sum of the squares of the elements of a Q31 vector. More...
 
void riscv_power_q7 (const q7_t *pSrc, uint32_t blockSize, q31_t *pResult)
 Sum of the squares of the elements of a Q7 vector. More...
 

Detailed Description

Calculates the sum of the squares of the elements in the input vector. The underlying algorithm is used:

    Result = pSrc[0] * pSrc[0] + pSrc[1] * pSrc[1] + pSrc[2] * pSrc[2] + ... + pSrc[blockSize-1] * pSrc[blockSize-1];

There are separate functions for floating point, Q31, Q15, and Q7 data types.

Since the result is not divided by the length, those functions are in fact computing something which is more an energy than a power.

Function Documentation

◆ riscv_power_f16()

void riscv_power_f16 ( const float16_t *  pSrc,
uint32_t  blockSize,
float16_t *  pResult 
)

Sum of the squares of the elements of a floating-point vector.

Parameters
[in]pSrcpoints to the input vector
[in]blockSizenumber of samples in input vector
[out]pResultsum of the squares value returned here
Returns
none

◆ riscv_power_f32()

void riscv_power_f32 ( const float32_t *  pSrc,
uint32_t  blockSize,
float32_t *  pResult 
)

Sum of the squares of the elements of a floating-point vector.

Parameters
[in]pSrcpoints to the input vector
[in]blockSizenumber of samples in input vector
[out]pResultsum of the squares value returned here
Returns
none

◆ riscv_power_f64()

void riscv_power_f64 ( const float64_t *  pSrc,
uint32_t  blockSize,
float64_t *  pResult 
)

Sum of the squares of the elements of a floating-point vector.

Parameters
[in]pSrcpoints to the input vector
[in]blockSizenumber of samples in input vector
[out]pResultsum of the squares value returned here
Returns
none

◆ riscv_power_q15()

void riscv_power_q15 ( const q15_t *  pSrc,
uint32_t  blockSize,
q63_t *  pResult 
)

Sum of the squares of the elements of a Q15 vector.

Parameters
[in]pSrcpoints to the input vector
[in]blockSizenumber of samples in input vector
[out]pResultsum of the squares value returned here
Returns
none
Scaling and Overflow Behavior
The function is implemented using a 64-bit internal accumulator. The input is represented in 1.15 format. Intermediate multiplication yields a 2.30 format, and this result is added without saturation to a 64-bit accumulator in 34.30 format. With 33 guard bits in the accumulator, there is no risk of overflow, and the full precision of the intermediate multiplication is preserved. Finally, the return result is in 34.30 format.

◆ riscv_power_q31()

void riscv_power_q31 ( const q31_t *  pSrc,
uint32_t  blockSize,
q63_t *  pResult 
)

Sum of the squares of the elements of a Q31 vector.

Parameters
[in]pSrcpoints to the input vector
[in]blockSizenumber of samples in input vector
[out]pResultsum of the squares value returned here
Returns
none
Scaling and Overflow Behavior
The function is implemented using a 64-bit internal accumulator. The input is represented in 1.31 format. Intermediate multiplication yields a 2.62 format, and this result is truncated to 2.48 format by discarding the lower 14 bits. The 2.48 result is then added without saturation to a 64-bit accumulator in 16.48 format. With 15 guard bits in the accumulator, there is no risk of overflow, and the full precision of the intermediate multiplication is preserved. Finally, the return result is in 16.48 format.

◆ riscv_power_q7()

void riscv_power_q7 ( const q7_t *  pSrc,
uint32_t  blockSize,
q31_t *  pResult 
)

Sum of the squares of the elements of a Q7 vector.

Parameters
[in]pSrcpoints to the input vector
[in]blockSizenumber of samples in input vector
[out]pResultsum of the squares value returned here
Returns
none
Scaling and Overflow Behavior
The function is implemented using a 32-bit internal accumulator. The input is represented in 1.7 format. Intermediate multiplication yields a 2.14 format, and this result is added without saturation to an accumulator in 18.14 format. With 17 guard bits in the accumulator, there is no risk of overflow, and the full precision of the intermediate multiplication is preserved. Finally, the return result is in 18.14 format.