---
title: vDSP_maxv
framework: Kernel
role: symbol
role_heading: Function
platforms: [macOS 10.4+]
path: kernel/1580003-vdsp_maxv
---

# vDSP_maxv

Calculates the maximum value in a single-precision vector.

## Declaration

```occ
void vDSP_maxv(const float *__A, vDSP_Stride __IA, float *__C, vDSP_Length __N);
```

## Parameters

- `__A`: Single-precision real input vector.
- `__I`: Stride for A.
- `__C`: Output scalar.
- `__N`: The number of elements to process. If N is zero (0), this function returns -INFINITY.

## Discussion

Discussion This function calculates the maximum value of the first N elements of A and writes the result to C:

The operation is:  *C = -INFINITY; for (n = 0; n < N; ++n)     if (*C < A[n*I])         *C = A[n*I]; The following code shows an example of using vDSP_maxv. let stride = vDSP_Stride(1)

let a: [Float] = [-1.5, 2.25, 3.6,                   0.2, -0.1, -4.3] let n = vDSP_Length(a.count)

var c: Float = .nan

vDSP_maxv(a,           stride,           &c,           n)

print("max", c) // Prints "max 3.6"