Complex Magnitude

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

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	(	float32_t *	pSrc,
		float32_t *	pDst,
		uint32_t	numSamples
	)

Parameters

[in]	*pSrc	points to complex input buffer
[out]	*pDst	points to real output buffer
[in]	numSamples	number of complex samples in the input vector

Returns

none.

Examples:

arm_fft_bin_example_f32.c.

References arm_sqrt_f32().

Referenced by main().

void arm_cmplx_mag_q15	(	q15_t *	pSrc,
		q15_t *	pDst,
		uint32_t	numSamples
	)

Parameters

*pSrc	points to the complex input vector
*pDst	points to the real output vector
numSamples	number of complex samples in the input 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.

References __SIMD32, and arm_sqrt_q15().

void arm_cmplx_mag_q31	(	q31_t *	pSrc,
		q31_t *	pDst,
		uint32_t	numSamples
	)

Parameters

*pSrc	points to the complex input vector
*pDst	points to the real output vector
numSamples	number of complex samples in the input 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.

References arm_sqrt_q31().