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# vDSP_zvphas

Calculates the single-precision element-wise phase values, in radians, of the supplied complex vector using the specified stride.

```
extern void vDSP_zvphas(const DSPSplitComplex *__A, vDSP_Stride __IA, float *__C, vDSP_Stride __IC, vDSP_Length __N);
```

## Parameters

`__A`

Single-precision complex input vector.

`__IA`

Stride for `A`.

`__C`

Single-precision real output vector.

`__IC`

Stride for `C`.

`__N`

The number of elements to process.

## Discussion

Finds the phase values, in radians, of complex vector `A` and store the results in real vector `C`. The results are between -pi and +pi. The sign of the result is the sign of the second coordinate in the input vector, except that the `vDSP_zvphas` function does not necessarily respect the sign of a zero input.

This performs the following operation:

```objc
for (n = 0; n < N; ++n)
   C[n] = atan2(Im(A[n]), Re(A[n]));
```

> Note:
> If both the inputs are `+0` or `-0`, the vDSP_zvphas function may return any value in `[-pi, +pi]`. If only one input is zero, the vDSP_zvphas function may return the result atan2 returns when the corresponding input is `+0` or `-0`.

---

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