CMSIS-DSP  Version 1.8.0
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Complex Magnitude

Functions

void arm_cmplx_mag_f32 (const float32_t *pSrc, float32_t *pDst, uint32_t numSamples)
 Floating-point complex magnitude. More...
 
void arm_cmplx_mag_q15 (const q15_t *pSrc, q15_t *pDst, uint32_t numSamples)
 Q15 complex magnitude. More...
 
void arm_cmplx_mag_q31 (const q31_t *pSrc, q31_t *pDst, uint32_t numSamples)
 Q31 complex magnitude. More...
 

Description

Computes the magnitude of the elements of a complex data vector.

The pSrc points to the source data and pDst points to the where the result should be written. numSamples specifies the number of complex samples in the input array and the data is stored in an interleaved fashion (real, imag, real, imag, ...). The input array has a total of 2*numSamples values; the output array has a total of numSamples values.

The underlying algorithm is used:

for (n = 0; n < numSamples; n++) {
    pDst[n] = sqrt(pSrc[(2*n)+0]^2 + pSrc[(2*n)+1]^2);
}

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

Function Documentation

void arm_cmplx_mag_f32 ( const float32_t pSrc,
float32_t pDst,
uint32_t  numSamples 
)
Parameters
[in]pSrcpoints to input vector
[out]pDstpoints to output vector
[in]numSamplesnumber of samples in each vector
Returns
none
void arm_cmplx_mag_q15 ( const q15_t pSrc,
q15_t pDst,
uint32_t  numSamples 
)
Parameters
[in]pSrcpoints to input vector
[out]pDstpoints to output vector
[in]numSamplesnumber of samples in each vector
Returns
none
Scaling and Overflow Behavior
The function implements 1.15 by 1.15 multiplications and finally output is converted into 2.14 format.
void arm_cmplx_mag_q31 ( const q31_t pSrc,
q31_t pDst,
uint32_t  numSamples 
)
Parameters
[in]pSrcpoints to input vector
[out]pDstpoints to output vector
[in]numSamplesnumber of samples in each vector
Returns
none
Scaling and Overflow Behavior
The function implements 1.31 by 1.31 multiplications and finally output is converted into 2.30 format. Input down scaling is not required.