---
title: vDSP_vmul
framework: Kernel
role: symbol
role_heading: Function
platforms: [macOS 10.0+]
path: kernel/1532206-vdsp_vmul
---

# vDSP_vmul

Multiplies two single-precision vectors.

## Declaration

```occ
void vDSP_vmul(const float *__A, vDSP_Stride __IA, const float *__B, vDSP_Stride __IB, float *__C, vDSP_Stride __IC, 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 C.
- `__C`: The single-precision real output vector.
- `__IC`: The stride for output vector C.
- `__N`: The number of elements to process.

## Discussion

Discussion This function calculates the products of the first N elements of input vectors A and B, writing the result to output vector C:

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

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

let n = vDSP_Length(a.count)

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

vDSP_vmul(b, stride,           a, stride,           &c, stride,           n)

// Prints "[10.0, 40.0, 90.0, 160.0, 250.0]". print(c)

## See Also

### Vector Arithmetic Functions

- [vDSP_vadd](kernel/1532191-vdsp_vadd.md)
- [vDSP_vma](kernel/1532193-vdsp_vma.md)
- [vDSP_vsub](kernel/1532189-vdsp_vsub.md)
- [vDSP_vsmul](kernel/1532223-vdsp_vsmul.md)
- [vDSP_vdiv](kernel/1532168-vdsp_vdiv.md)