Function

# vDSP_maxmgviD(_:_:_:_:_:)

Calculates the maximum magnitude and corresponding index in a double-precision vector.

## Parameters

`__A`

Double-precision real input vector.

`__I`

Stride for `A`.

`__C`

Output scalar.

`__IC`

Output scalar index.

`__N`

The number of elements to process. If `N` is zero (`0`), this function returns `-INFINITY` in `C`, and the value in `IC` is undefined.

## Discussion

This function calculates the maximum magnitude and corresonding index of the first `N` elements of `A` and writes the result to `C`:

The index is the actual array index, not the pre-stride index. If vector `A` contains more than one instance of the maximum value, `IC` contains the index of the first instance.

The operation is:

### Maximum Calculation

`static func maximum<U>(U) -> Double`

Returns the maximum element in a double-precision vector.

`static func maximum<U>(U) -> Float`

Returns the maximum element in a single-precision vector.

`static func maximumMagnitude<U>(U) -> Double`

Returns the maximum magnitude element in a double-precision vector.

`static func maximumMagnitude<U>(U) -> Float`

Returns the maximum magnitude element in a single-precision vector.

`static func indexOfMaximum<U>(U) -> (UInt, Double)`

Returns the maximum element, and its index, in a double-precision vector.

`static func indexOfMaximum<U>(U) -> (UInt, Float)`

Returns the maximum element, and its index, in a signal-precision vector.

`static func indexOfMaximumMagnitude<U>(U) -> (UInt, Double)`

Returns the maximum magnitude element, and its index, in a double-precision vector.

`static func indexOfMaximumMagnitude<U>(U) -> (UInt, Float)`

Returns the maximum magnitude element, and its index, in a single-precision vector.

Beta Software

This documentation contains preliminary information about an API or technology in development. This information is subject to change, and software implemented according to this documentation should be tested with final operating system software.