---
title: vDSP_vma
framework: Kernel
role: symbol
role_heading: Function
platforms: [macOS 10.4+]
path: kernel/1532193-vdsp_vma
---

# vDSP_vma

Adds a single-precision vector to the product of two single-precision vectors.

## Declaration

```occ
void vDSP_vma(const float *__A, vDSP_Stride __IA, const float *__B, vDSP_Stride __IB, const float *__C, vDSP_Stride __IC, float *__D, vDSP_Stride __ID, vDSP_Length __N);
```

## Parameters

- `__A`: The single-precision real input vector A.
- `__IA`: The stride for input vector A.
- `__B`: The single-precision real input vector B.
- `__IB`: The stride for input vector B.
- `__C`: The single-precision real input vector C.
- `__IC`: The stride for input vector C.
- `__D`: The single-precision real output vector.
- `__ID`: The stride for output vector D.
- `__N`: The number of elements to process.

## Discussion

Discussion This function calculates the products of the first N elements of A and B, adds each product to the corresponding value in C, and writes the result to D:

The operation is:  for (n = 0; n < N; ++n)     D[n] = A[n] * B[n] + C[n]; The following code shows an example of using vDSP_vma: let stride = vDSP_Stride(1)

let a: [Float] = [10, 20, 30, 40, 50] let b: [Float] = [ 1,  2,  3,  4,  5]

let c: [Float] = [1, 2, 3, 4, 5]

let n = vDSP_Length(a.count)

var d = [Float](repeating: 0,                 count: a.count)

vDSP_vma(a, stride,          b, stride,          c, stride,          &d, stride,          n)

// Prints "[11.0, 42.0, 93.0, 164.0, 255.0]". print(d)

## See Also

### Vector Arithmetic Functions

- [vDSP_vadd](kernel/1532191-vdsp_vadd.md)
- [vDSP_vsub](kernel/1532189-vdsp_vsub.md)
- [vDSP_vmul](kernel/1532206-vdsp_vmul.md)
- [vDSP_vsmul](kernel/1532223-vdsp_vsmul.md)
- [vDSP_vdiv](kernel/1532168-vdsp_vdiv.md)