---
title: simd_double2
framework: simd
role: symbol
role_heading: Type Alias
path: simd/simd_double2
---

# simd_double2

A vector of two 64-bit floating-point elements.

## Declaration

```swift
typealias simd_double2 = SIMD2<Double>
```

## Topics

### Functions to Create Two-Element Vectors From Other Vectors

- [simd_make_double2(_:)](simd/simd_make_double2(_:)-3qby3.md)
- [simd_make_double2(_:)](simd/simd_make_double2(_:)-3tt38.md)
- [simd_make_double2(_:)](simd/simd_make_double2(_:)-3hpld.md)
- [simd_make_double2(_:)](simd/simd_make_double2(_:)-4o3ot.md)
- [simd_make_double2(_:_:)](simd/simd_make_double2(_:_:).md)

### Functions to Create Two-Element Vectors From Scalar Values

- [simd_make_double2(_:)](simd/simd_make_double2(_:)-r6xz.md)
- [simd_make_double2_undef(_:)](simd/simd_make_double2_undef(_:).md)

### Common Functions

- [simd_abs(_:)](simd/simd_abs(_:)-8869e.md)
- [abs(_:)](simd/abs(_:)-1p8t7.md)
- [simd_clamp(_:_:_:)](simd/simd_clamp(_:_:_:)-6puwa.md)
- [clamp(_:min:max:)](simd/clamp(_:min:max:)-7n2jv.md)
- [clamp(_:min:max:)](simd/clamp(_:min:max:)-6d1s7.md)
- [simd_equal(_:_:)](simd/simd_equal(_:_:)-vmn4.md)
- [simd_fract(_:)](simd/simd_fract(_:)-42i3r.md)
- [fract(_:)](simd/fract(_:)-2gjrn.md)
- [simd_sign(_:)](simd/simd_sign(_:)-6jlx9.md)
- [sign(_:)](simd/sign(_:)-5fczz.md)
- [step(_:edge:)](simd/step(_:edge:)-2qauk.md)
- [simd_step(_:_:)](simd/simd_step(_:_:)-8jlf2.md)

### Reduce Functions

- [simd_reduce_add(_:)](simd/simd_reduce_add(_:)-2q09i.md)
- [reduce_add(_:)](simd/reduce_add(_:)-8iwo6.md)
- [simd_reduce_max(_:)](simd/simd_reduce_max(_:)-4kinw.md)
- [reduce_max(_:)](simd/reduce_max(_:)-3rmpx.md)
- [simd_reduce_min(_:)](simd/simd_reduce_min(_:)-49t1o.md)
- [reduce_min(_:)](simd/reduce_min(_:)-6mev7.md)

### Interpolation Functions

- [simd_smoothstep(_:_:_:)](simd/simd_smoothstep(_:_:_:)-e0ov.md)
- [smoothstep(_:edge0:edge1:)](simd/smoothstep(_:edge0:edge1:)-2wqo9.md)
- [simd_mix(_:_:_:)](simd/simd_mix(_:_:_:)-v083.md)
- [mix(_:_:t:)](simd/mix(_:_:t:)-7bjg5.md)
- [mix(_:_:t:)](simd/mix(_:_:t:)-3hfwb.md)

### Extrema Functions

- [simd_max(_:_:)](simd/simd_max(_:_:)-1sy2n.md)
- [max(_:_:)](simd/max(_:_:)-3puhr.md)
- [max(_:_:)](simd/max(_:_:)-8a5p5.md)
- [fmax(_:_:)](simd/fmax(_:_:)-15te9.md)
- [simd_min(_:_:)](simd/simd_min(_:_:)-9mraz.md)
- [min(_:_:)](simd/min(_:_:)-4sdw0.md)
- [min(_:_:)](simd/min(_:_:)-9yz9x.md)
- [fmin(_:_:)](simd/fmin(_:_:)-39mes.md)

### Reciprocal and Reciprocal Square Root Functions

- [recip(_:)](simd/recip(_:)-43mv7.md)
- [simd_recip(_:)](simd/simd_recip(_:)-8nekc.md)
- [simd_fast_recip(_:)](simd/simd_fast_recip(_:)-lm0t.md)
- [simd_precise_recip(_:)](simd/simd_precise_recip(_:)-66n8k.md)
- [simd_rsqrt(_:)](simd/simd_rsqrt(_:)-ok9s.md)
- [rsqrt(_:)](simd/rsqrt(_:)-2k5rh.md)
- [simd_fast_rsqrt(_:)](simd/simd_fast_rsqrt(_:)-84dca.md)
- [simd_precise_rsqrt(_:)](simd/simd_precise_rsqrt(_:)-wrke.md)

### Exponential and Logarithmic Functions

- [exp(_:)](simd/exp(_:)-9nxip.md)
- [exp2(_:)](simd/exp2(_:)-4y2ne.md)
- [exp10(_:)](simd/exp10(_:)-4tdos.md)
- [expm1(_:)](simd/expm1(_:)-9aitr.md)
- [log(_:)](simd/log(_:)-2ieba.md)
- [log2(_:)](simd/log2(_:)-779eu.md)
- [log10(_:)](simd/log10(_:)-337zw.md)
- [log1p(_:)](simd/log1p(_:)-40mka.md)

### Geometry Functions

- [cross(_:_:)](simd/cross(_:_:)-916aw.md)
- [dot(_:_:)](simd/dot(_:_:)-6ayky.md)
- [normalize(_:)](simd/normalize(_:)-5mqhk.md)
- [project(_:_:)](simd/project(_:_:)-kai1.md)
- [reflect(_:n:)](simd/reflect(_:n:)-3rhgb.md)
- [refract(_:n:eta:)](simd/refract(_:n:eta:)-1ghae.md)

### Vector Norm Functions

- [norm_one(_:)](simd/norm_one(_:)-2uh74.md)
- [norm_inf(_:)](simd/norm_inf(_:)-s3p1.md)

### Length and Distance Functions

- [length(_:)](simd/length(_:)-4gxdk.md)
- [length_squared(_:)](simd/length_squared(_:)-8gxz9.md)
- [distance(_:_:)](simd/distance(_:_:)-1mnxv.md)
- [distance_squared(_:_:)](simd/distance_squared(_:_:)-56tah.md)

### Hyperbolic Functions

- [acosh(_:)](simd/acosh(_:)-edu.md)
- [asinh(_:)](simd/asinh(_:)-nxaa.md)
- [atanh(_:)](simd/atanh(_:)-5l8ss.md)
- [cosh(_:)](simd/cosh(_:)-303ot.md)
- [sinh(_:)](simd/sinh(_:)-5gx9h.md)
- [tanh(_:)](simd/tanh(_:)-739hq.md)

### Logic Functions

- [simd_select(_:_:_:)](simd/simd_select(_:_:_:)-7sz6k.md)
- [simd_bitselect(_:_:_:)](simd/simd_bitselect(_:_:_:)-3ys1a.md)

### Math Functions

- [cbrt(_:)](simd/cbrt(_:)-75bqn.md)
- [ceil(_:)](simd/ceil(_:)-cu6z.md)
- [erf(_:)](simd/erf(_:)-7tfrz.md)
- [erfc(_:)](simd/erfc(_:)-8i2r6.md)
- [floor(_:)](simd/floor(_:)-21h1y.md)
- [fma(_:_:_:)](simd/fma(_:_:_:)-4fxau.md)
- [fmod(_:_:)](simd/fmod(_:_:)-81hr1.md)
- [hypot(_:_:)](simd/hypot(_:_:)-9ecpz.md)
- [lgamma(_:)](simd/lgamma(_:)-697vf.md)
- [nextafter(_:_:)](simd/nextafter(_:_:)-6qeuz.md)
- [pow(_:_:)](simd/pow(_:_:)-2ov0n.md)
- [remainder(_:_:)](simd/remainder(_:_:)-1l80m.md)
- [round(_:)](simd/round(_:)-1ith.md)
- [simd_muladd(_:_:_:)](simd/simd_muladd(_:_:_:)-o9lv.md)
- [tgamma(_:)](simd/tgamma(_:)-3id8t.md)
- [trunc(_:)](simd/trunc(_:)-1xvcu.md)

### Trigonometric Functions

- [acos(_:)](simd/acos(_:)-1hgv5.md)
- [asin(_:)](simd/asin(_:)-72orw.md)
- [atan(_:)](simd/atan(_:)-9onaa.md)
- [atan2(_:_:)](simd/atan2(_:_:)-6ogu4.md)
- [cos(_:)](simd/cos(_:)-3p9ym.md)
- [cospi(_:)](simd/cospi(_:)-57353.md)
- [sin(_:)](simd/sin(_:)-3p88b.md)
- [sinpi(_:)](simd/sinpi(_:)-4lgpo.md)
- [sincos(_:)](simd/sincos(_:)-9pa2l.md)
- [sincospi(_:)](simd/sincospi(_:)-3fwbj.md)
- [tan(_:)](simd/tan(_:)-5czlf.md)
- [tanpi(_:)](simd/tanpi(_:)-9z76.md)

### Classification Functions

- [isfinite(_:)](simd/isfinite(_:)-7d8q7.md)
- [isinf(_:)](simd/isinf(_:)-4wflm.md)
- [isnan(_:)](simd/isnan(_:)-9irpc.md)
- [isnormal(_:)](simd/isnormal(_:)-61nr1.md)

### Alternative Type Alias

- [vector_double2](simd/vector_double2.md)
- [double2](simd/double2.md)

## See Also

### Vector data types

- [simd_double1](simd/simd_double1.md)
- [simd_double3](simd/simd_double3.md)
- [simd_double4](simd/simd_double4.md)
- [simd_double8](simd/simd_double8.md)