CMSIS-DSP: Complex Magnitude

| CMSIS-DSP Version 1.8.0 CMSIS DSP Software Library

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Complex Magnitude
Complex Math Functions

## 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] | pSrc | points to input vector
  [out] | pDst | points to output vector
  [in] | numSamples | number of samples in each vector

Returns
  none

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

Parameters

  [in] | pSrc | points to input vector
  [out] | pDst | points to output vector
  [in] | numSamples | number 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] | pSrc | points to input vector
  [out] | pDst | points to output vector
  [in] | numSamples | number 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.