---
title: vDSP_vsmul
framework: Kernel
role: symbol
role_heading: Function
platforms: [macOS 10.0+]
path: kernel/1532223-vdsp_vsmul
---

# vDSP_vsmul

Multiplies a single-precision scalar value by a single-precision vector.

## Declaration

```occ
void vDSP_vsmul(const float *__A, vDSP_Stride __IA, const float *__B, 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`: A pointer to the single-precision real input scalar.
- `__C`: The single-precision real output vector.
- `__IC`: The stride for output vector C.
- `__N`: The number of elements to multiply.

## Discussion

Discussion This function calculates the products of the first N elements of A and the scalar value B, writing the result to C:

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

let a: [Float] = [1, 2, 4, 5] var b: Float = 2

let n = vDSP_Length(a.count)

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

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

// Prints "[2.0, 4.0, 8.0, 10.0]". 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_vmul](kernel/1532206-vdsp_vmul.md)
- [vDSP_vdiv](kernel/1532168-vdsp_vdiv.md)