# simd_double4 A vector of four 64-bit floating-point elements. ``` typealias simd_double4 = SIMD4 ``` ## Topics ### Functions to Create Four-Element Vectors From Other Vectors [`simd_make_double4(_:)`](/documentation/simd/simd_make_double4(_:)-3ft6m) Returns a new vector from the specified two-element vector, and other elements set to zero. [`simd_make_double4(_:)`](/documentation/simd/simd_make_double4(_:)-3jd0t) Returns a new vector from the specified three-element vector, and other elements set to zero. [`simd_make_double4(_:)`](/documentation/simd/simd_make_double4(_:)-3ofj0) Returns a new vector from the specified vector. [`simd_make_double4(_:)`](/documentation/simd/simd_make_double4(_:)-41bao) Returns a new vector by truncating the specified eight-element vector. [`simd_make_double4(_:_:)`](/documentation/simd/simd_make_double4(_:_:)-68v0e) Returns a new vector from the specified vectors. [`vector4`](/documentation/simd/vector4-15myv) Returns a new vector from the specified vectors. [`simd_make_double4_undef(_:)`](/documentation/simd/simd_make_double4_undef(_:)-6brs0) Returns a new vector from the specified two-element vector, and other elements undefined. [`simd_make_double4_undef(_:)`](/documentation/simd/simd_make_double4_undef(_:)-68wqb) Returns a new vector from the specified three-element vector, and other elements undefined. ### Functions to Create Four-Element Vectors From Scalar Values [`simd_make_double4(_:)`](/documentation/simd/simd_make_double4(_:)-2zeiq) Returns a new vector with the first element set to a scalar value, and other elements set to zero. [`simd_make_double4(_:_:_:_:)`](/documentation/simd/simd_make_double4(_:_:_:_:)) Returns a new vector from the specified scalar values. [`vector4`](/documentation/simd/vector4-4b8da) Returns a new vector from the specified scalar values. [`simd_make_double4_undef(_:)`](/documentation/simd/simd_make_double4_undef(_:)-22old) Returns a new vector with the first element set to a scalar value, and other elements undefined. ### Functions to Create Four-Element Vectors From Combinations of Vectors and Scalar Values [`simd_make_double4(_:_:_:)`](/documentation/simd/simd_make_double4(_:_:_:)-51v00) Returns a new vector from two scalar values and a vector. [`simd_make_double4(_:_:_:)`](/documentation/simd/simd_make_double4(_:_:_:)-8f2vh) Returns a new vector from a scalar value, a vector, and a scalar value. [`simd_make_double4(_:_:)`](/documentation/simd/simd_make_double4(_:_:)-1ifzl) Returns a new vector from a scalar value and a vector. [`simd_make_double4(_:_:_:)`](/documentation/simd/simd_make_double4(_:_:_:)-8b5fy) Returns a new vector from a vector and scalar values. [`simd_make_double4(_:_:)`](/documentation/simd/simd_make_double4(_:_:)-767qm) Returns a new vector from a vector and a scalar value. [`vector4`](/documentation/simd/vector4-23zx8) Returns a new vector from a vector and a scalar value. ### Functions to Create Four-Element Vectors From Vectors of Other Types [`simd_double`](/documentation/simd/simd_double-5p2h2) Returns a new vector from the specified vector of 8-bit, signed-integer elements. [`simd_double`](/documentation/simd/simd_double-5osau) Returns a new vector from the specified vector of 8-bit, unsigned-integer elements. [`simd_double`](/documentation/simd/simd_double-5oxie) Returns a new vector from the specified vector of 16-bit, signed-integer elements. [`simd_double`](/documentation/simd/simd_double-5onhi) Returns a new vector from the specified vector of 16-bit, unsigned-integer elements. [`simd_double`](/documentation/simd/simd_double-5p456) Returns a new vector from the specified vector of 32-bit, signed-integer elements. [`simd_double`](/documentation/simd/simd_double-5ouey) Returns a new vector from the specified vector of 32-bit, unsigned-integer elements. [`simd_double`](/documentation/simd/simd_double-5p376) Returns a new vector from the specified vector of 64-bit, signed-integer elements. [`simd_double`](/documentation/simd/simd_double-5ot9u) Returns a new vector from the specified vector of 64-bit, unsigned-integer elements. [`simd_double`](/documentation/simd/simd_double-5orke) Returns a new vector from the specified vector of 32-bit, floating-point elements. [`simd_double`](/documentation/simd/simd_double-5oqzm) Returns a new vector from the specified vector of 64-bit, floating-point elements. ### Common Functions [`simd_abs(_:)`](/documentation/simd/simd_abs(_:)-81rjc) Returns the absolute value of each element in a vector. [`abs(_:)`](/documentation/simd/abs(_:)-63bb7) Returns the absolute value of each element in a vector. [`simd_clamp(_:_:_:)`](/documentation/simd/simd_clamp(_:_:_:)-8skia) Returns each element in a vector clamped to a specified range. [`clamp(_:min:max:)`](/documentation/simd/clamp(_:min:max:)-3iua3) Returns each element in a vector clamped to a specified range. [`clamp(_:min:max:)`](/documentation/simd/clamp(_:min:max:)-51jkt) Returns each element in a vector clamped to a specified range. [`simd_fract(_:)`](/documentation/simd/simd_fract(_:)-3w3dh) Returns the fractional part of each element in a vector. [`fract(_:)`](/documentation/simd/fract(_:)-8mowg) Returns the fractional part of each element in a vector. [`simd_equal(_:_:)`](/documentation/simd/simd_equal(_:_:)-6lpka) Returns true if every element in a vector is exactly equal to the corresponding element in a second vector, and otherwise returns false. [`simd_sign(_:)`](/documentation/simd/simd_sign(_:)-74z7b) Returns the sign of each element in a vector. [`sign(_:)`](/documentation/simd/sign(_:)-86tur) Returns the sign of each element in a vector. [`simd_step(_:_:)`](/documentation/simd/simd_step(_:_:)-6nrf4) Returns zero for each element in a vector less than a specified edge, and otherwise returns one. [`step(_:edge:)`](/documentation/simd/step(_:edge:)-641e1) Returns zero for each element in a vector less than a specified edge, and otherwise returns one. ### Reduce Functions [`simd_reduce_add(_:)`](/documentation/simd/simd_reduce_add(_:)-2ymlg) Returns the sum of all elements in a vector. [`reduce_add(_:)`](/documentation/simd/reduce_add(_:)-7psay) Returns the sum of all elements in a vector. [`simd_reduce_max(_:)`](/documentation/simd/simd_reduce_max(_:)-4qv3y) Returns the maximum value in a vector. [`reduce_max(_:)`](/documentation/simd/reduce_max(_:)-66smw) Returns the maximum value in a vector. [`simd_reduce_min(_:)`](/documentation/simd/simd_reduce_min(_:)-4umgm) Returns the minimum value in a vector. [`reduce_min(_:)`](/documentation/simd/reduce_min(_:)-4bbr) Returns the minimum value in a vector. ### Interpolation Functions [`simd_smoothstep(_:_:_:)`](/documentation/simd/simd_smoothstep(_:_:_:)-6idlb) Returns an element-wise smoothly interpolated value between two vectors. [`smoothstep(_:edge0:edge1:)`](/documentation/simd/smoothstep(_:edge0:edge1:)-3gmrv) Returns an element-wise smoothly interpolated value between two vectors. [`simd_mix(_:_:_:)`](/documentation/simd/simd_mix(_:_:_:)-49aeg) Returns an element-wise linearly interpolated value between two vectors. [`mix(_:_:t:)`](/documentation/simd/mix(_:_:t:)-9jxxl) Returns an element-wise linearly interpolated value between two vectors. [`mix(_:_:t:)`](/documentation/simd/mix(_:_:t:)-92fbo) Returns an element-wise linearly interpolated value between two vectors. ### Extrema Functions [`simd_max(_:_:)`](/documentation/simd/simd_max(_:_:)-72b4) Returns the maximum value of each element in a vector. [`max(_:_:)`](/documentation/simd/max(_:_:)-82ig0) Returns the maximum value of each element in a vector. [`max(_:_:)`](/documentation/simd/max(_:_:)-4pgdo) Returns the maximum value of each element in a vector. [`fmax(_:_:)`](/documentation/simd/fmax(_:_:)-60f6g) Returns the maximum value of each element in a vector. [`simd_min(_:_:)`](/documentation/simd/simd_min(_:_:)-78g6s) Returns the minimum value of each element in a vector. [`min(_:_:)`](/documentation/simd/min(_:_:)-7rmn) Returns the minimum value of each element in a vector. [`min(_:_:)`](/documentation/simd/min(_:_:)-8m4sw) Returns the minimum value of each element in a vector. [`fmin(_:_:)`](/documentation/simd/fmin(_:_:)-4joph) Returns the minimum value of each element in a vector. ### Reciprocal and Reciprocal Square Root Functions [`simd_recip(_:)`](/documentation/simd/simd_recip(_:)-8218m) Returns the reciprocal of each element in a vector. [`recip(_:)`](/documentation/simd/recip(_:)-2zcya) Returns the reciprocal of each element in a vector. [`simd_rsqrt(_:)`](/documentation/simd/simd_rsqrt(_:)-i5ka) Returns the reciprocal square root of each element in a vector. [`rsqrt(_:)`](/documentation/simd/rsqrt(_:)-8rb58) Returns the reciprocal square root of each element in a vector. [`simd_precise_recip(_:)`](/documentation/simd/simd_precise_recip(_:)-6pt5q) Returns the precise reciprocal of each element in a vector. [`simd_precise_rsqrt(_:)`](/documentation/simd/simd_precise_rsqrt(_:)-136bw) Returns the precise reciprocal square root of each element in a vector. [`simd_fast_recip(_:)`](/documentation/simd/simd_fast_recip(_:)-61j) Returns the fast reciprocal of each element in a vector. [`simd_fast_rsqrt(_:)`](/documentation/simd/simd_fast_rsqrt(_:)-8p6tk) Returns the fast reciprocal square root of each element in a vector. ### Exponential and Logarithmic Functions [`exp(_:)`](/documentation/simd/exp(_:)-92zj) Returns *e* raised to the power of each element in a vector. [`exp2(_:)`](/documentation/simd/exp2(_:)-6nz50) Returns 2 raised to the power of each element in a vector. [`exp10(_:)`](/documentation/simd/exp10(_:)-apfo) Returns 10 raised to the power of each element in a vector. [`expm1(_:)`](/documentation/simd/expm1(_:)-4osfq) Returns *eˣ-1* for each element in a vector. [`log(_:)`](/documentation/simd/log(_:)-54908) Returns the natural logarithm of each element in a vector. [`log2(_:)`](/documentation/simd/log2(_:)-2m5uu) Returns the base 2 logarithm of each element in a vector. [`log10(_:)`](/documentation/simd/log10(_:)-80x29) Returns the base 10 logarithm of each element in a vector. [`log1p(_:)`](/documentation/simd/log1p(_:)-t4r0) Returns *log(1+x)* of each element in a vector. [`exp`](/documentation/simd/exp) Returns *e* raised to the power of each element in a vector. [`exp2`](/documentation/simd/exp2) Returns 2 raised to the power of each element in a vector. [`exp10`](/documentation/simd/exp10) Returns 10 raised to the power of each element in a vector. [`expm1`](/documentation/simd/expm1) Returns *eˣ-1* for each element in a vector. [`log`](/documentation/simd/log) Returns the natural logarithm of each element in a vector. [`log2`](/documentation/simd/log2) Returns the base 2 logarithm of each element in a vector. [`log10`](/documentation/simd/log10) Returns the base 10 logarithm of each element in a vector. [`log1p`](/documentation/simd/log1p) Returns *log(1+x)* for each element in a vector. ### Geometry Functions [`simd_dot`](/documentation/simd/simd_dot-85nay) Returns the dot product of two vectors. [`dot(_:_:)`](/documentation/simd/dot(_:_:)-5ifd) Returns the dot product of two vectors. [`simd_normalize`](/documentation/simd/simd_normalize-9o7wa) Returns a vector pointing in the same direction of the supplied vector, with a length of 1. [`normalize(_:)`](/documentation/simd/normalize(_:)-3lhrd) Returns a vector pointing in the same direction of the supplied vector with a length of 1. [`simd_fast_normalize`](/documentation/simd/simd_fast_normalize-3rv7) Returns the fast normalized vector. [`simd_precise_normalize`](/documentation/simd/simd_precise_normalize-4vtps) Returns the precise normalized vector. [`simd_project`](/documentation/simd/simd_project-6cfku) Returns the first vector projected onto the second vector. [`project(_:_:)`](/documentation/simd/project(_:_:)-1uuxo) Returns the first vector projected onto the second vector. [`simd_fast_project`](/documentation/simd/simd_fast_project-6urv1) Returns the fast projected vector. [`simd_precise_project`](/documentation/simd/simd_precise_project-1f1gc) Returns the precise projected vector. [`simd_reflect`](/documentation/simd/simd_reflect-91ah5) Returns the reflection direction of an incident vector and a unit normal vector. [`reflect(_:n:)`](/documentation/simd/reflect(_:n:)-1nabs) Returns the reflection direction of an incident vector and a unit normal vector. [`simd_refract`](/documentation/simd/simd_refract-7dskm) Returns the refraction direction of an incident vector, a unit normal vector, and an index of refraction eta. [`refract(_:n:eta:)`](/documentation/simd/refract(_:n:eta:)-2macj) Returns the refraction direction of an incident vector, a unit normal vector, and an index of refraction eta. ### Vector Norm Functions [`simd_norm_one`](/documentation/simd/simd_norm_one-scnf) Returns the sum of the absolute values of a vector. [`norm_one(_:)`](/documentation/simd/norm_one(_:)-1cwpd) Returns the sum of the absolute values of a vector. [`simd_norm_inf`](/documentation/simd/simd_norm_inf-97qpi) Returns the maximum absolute value of a vector. [`norm_inf(_:)`](/documentation/simd/norm_inf(_:)-8zws7) Returns the maximum absolute value of a vector. ### Length and Distance Functions [`simd_length`](/documentation/simd/simd_length-3fo5n) Returns the length of a vector. [`length(_:)`](/documentation/simd/length(_:)-79i68) Returns the length of a vector. [`simd_fast_length`](/documentation/simd/simd_fast_length-4okp0) Returns the fast length of a vector. [`simd_precise_length`](/documentation/simd/simd_precise_length-7dt8e) Returns the precise length of a vector. [`simd_length_squared`](/documentation/simd/simd_length_squared-2t7x9) Returns the square of the length of a vector. [`length_squared(_:)`](/documentation/simd/length_squared(_:)-856uz) Returns the square of the length of a vector. [`simd_distance`](/documentation/simd/simd_distance-9rhec) Returns the distance between two vectors. [`distance(_:_:)`](/documentation/simd/distance(_:_:)-559m9) Returns the distance between two vectors. [`simd_fast_distance`](/documentation/simd/simd_fast_distance-13ukv) Returns the fast distance between two vectors. [`simd_precise_distance`](/documentation/simd/simd_precise_distance-5ywfl) Returns the precise distance between two vectors. [`simd_distance_squared`](/documentation/simd/simd_distance_squared-42eds) Returns the square of the distance between two vectors. [`distance_squared(_:_:)`](/documentation/simd/distance_squared(_:_:)-73nv3) Returns the square of the distance between two vectors. ### Hyperbolic Functions [`acosh(_:)`](/documentation/simd/acosh(_:)-2a3a) Returns the inverse hyperbolic cosine of each element in a vector. [`asinh(_:)`](/documentation/simd/asinh(_:)-847y) Returns the inverse hyperbolic sine of each element in a vector. [`atanh(_:)`](/documentation/simd/atanh(_:)-17pza) Returns the inverse hyperbolic tangent of each element in a vector. [`cosh(_:)`](/documentation/simd/cosh(_:)-8h0te) Returns the hyperbolic cosine of each element in a vector. [`sinh(_:)`](/documentation/simd/sinh(_:)-3rjw6) Returns the hyperbolic sine of each element in a vector. [`tanh(_:)`](/documentation/simd/tanh(_:)-x8vt) Returns the hyperbolic tangent of each element in a vector. [`acosh`](/documentation/simd/acosh) Returns the inverse hyperbolic cosine of each element in a vector. [`asinh`](/documentation/simd/asinh) Returns the inverse hyperbolic sine of each element in a vector. [`atanh`](/documentation/simd/atanh) Returns the inverse hyperbolic tangent of each element in a vector. [`cosh`](/documentation/simd/cosh) Returns the hyperbolic cosine of each element in a vector. [`sinh`](/documentation/simd/sinh) Returns the hyperbolic sine of each element in a vector. [`tanh`](/documentation/simd/tanh) Returns the hyperbolic tangent of each element in a vector. ### Logic Functions [`simd_select(_:_:_:)`](/documentation/simd/simd_select(_:_:_:)-tq6k) Returns a vector that contains elements from either the first or second parameter, based on the corresponding element’s high-order bit in the mask. [`simd_bitselect(_:_:_:)`](/documentation/simd/simd_bitselect(_:_:_:)-1mn6g) Returns a vector that contains elements from either the first or second parameter, based on the corresponding element in the third parameter. ### Math Functions [`cbrt(_:)`](/documentation/simd/cbrt(_:)-7pm3s) Returns the cube root of each element in a vector. [`ceil(_:)`](/documentation/simd/ceil(_:)-9s503) Returns the ceiling of each element in a vector. [`erf(_:)`](/documentation/simd/erf(_:)-1yjjk) Returns the error function for each element in a vector. [`erfc(_:)`](/documentation/simd/erfc(_:)-6rgzx) Returns the complementary error function for each element in a vector. [`floor(_:)`](/documentation/simd/floor(_:)-3956i) Returns the floor of each element in a vector. [`fma(_:_:_:)`](/documentation/simd/fma(_:_:_:)-6mqpv) Returns the multiply-add result for corresponding elements in three vectors. [`fmod(_:_:)`](/documentation/simd/fmod(_:_:)-92tjw) Returns the modulus after dividing each element in a vector by the corresponding element in a second vector. [`hypot(_:_:)`](/documentation/simd/hypot(_:_:)-2exik) Returns the hypotenuse of a right-angled triangle with the sides that are adjacent to the right angle that two vectors define. [`lgamma(_:)`](/documentation/simd/lgamma(_:)-2frmv) Returns the natural logarithm of the absolute value of the gamma function of each element in a vector. [`nextafter(_:_:)`](/documentation/simd/nextafter(_:_:)-oxq7) Returns the next representable value of each element in a vector in the direction of the corresponding element in a second vector. [`pow(_:_:)`](/documentation/simd/pow(_:_:)-3jh7o) Returns each element in a vector raised to the power of the corresponding element in a second vector. [`remainder(_:_:)`](/documentation/simd/remainder(_:_:)-jw8b) Returns the remainder after dividing each element in an array by the corresponding element in a second array of double-precision values. [`round(_:)`](/documentation/simd/round(_:)-5ytc6) Returns each element in a vector rounded to the nearest integer. [`cbrt`](/documentation/simd/cbrt) Returns the cube root of each element in a vector. [`copysign`](/documentation/simd/copysign) Returns each element of a vector, with the sign of the corresponding element in a second vector. [`erf`](/documentation/simd/erf) Returns the error function for each element in a vector. [`erfc`](/documentation/simd/erfc) Returns the complementary error function for each element in a vector. [`fabs`](/documentation/simd/fabs) Returns the absolute value of each element in a vector. [`fdim`](/documentation/simd/fdim) Returns the positive difference between corresponding elements in two vectors. [`fma`](/documentation/simd/fma) Returns the multiply-add result for corresponding elements in three vectors. [`fmod`](/documentation/simd/fmod) Returns the modulus after dividing each element in a vector by the corresponding element in a second vector. [`hypot`](/documentation/simd/hypot) Returns the hypotenuse of a right-angled triangle with the sides that are adjacent to the right angle that two vectors define. [`nextafter`](/documentation/simd/nextafter) Returns the next representable value of each element in a vector in the direction of the corresponding element in a second vector. [`pow`](/documentation/simd/pow) Returns each element in a vector raised to the power of the corresponding element in a second vector. [`remainder`](/documentation/simd/remainder) Returns the remainder after dividing each element in an array by the corresponding element in a second array of double-precision values. [`rint`](/documentation/simd/rint) Returns each element in a vector rounded to the nearest integer in the specified direction. [`round`](/documentation/simd/round) Returns each element in a vector rounded to the nearest integer. [`simd_muladd(_:_:_:)`](/documentation/simd/simd_muladd(_:_:_:)-6kpyx) Returns the multiply-add result for corresponding elements in three vectors. [`tgamma(_:)`](/documentation/simd/tgamma(_:)-2o8vo) Returns the gamma function for each element in a vector. [`trunc(_:)`](/documentation/simd/trunc(_:)-9n2h5) Returns each element in a vector rounded toward zero to the nearest integer. [`sqrt`](/documentation/simd/sqrt) Returns the square root of each element in a vector. [`tgamma`](/documentation/simd/tgamma) Returns the gamma function for each element in a vector. ### Trigonometric Functions [`acos(_:)`](/documentation/simd/acos(_:)-9cb48) Returns the arccosine of each element in a vector. [`asin(_:)`](/documentation/simd/asin(_:)-70soc) Returns the arcsine of each element in a vector. [`atan(_:)`](/documentation/simd/atan(_:)-5w6c7) Returns the arctangent of each element in a vector. [`atan2(_:_:)`](/documentation/simd/atan2(_:_:)-19fnn) Returns the arctangent of each pair of corresponding elements in two vectors. [`cos(_:)`](/documentation/simd/cos(_:)-1leci) Returns the cosine of each element in a vector. [`cospi(_:)`](/documentation/simd/cospi(_:)-8cke2) Returns the cosine of each element in a vector multiplied by pi. [`sin(_:)`](/documentation/simd/sin(_:)-67ulu) Returns the sine of each element in a vector. [`sinpi(_:)`](/documentation/simd/sinpi(_:)-45nf0) Returns the sine of each element in a vector multiplied by pi. [`sincos(_:)`](/documentation/simd/sincos(_:)-9olep) Returns the sine and cosine of each element in a vector. [`sincospi(_:)`](/documentation/simd/sincospi(_:)-40ymv) Returns the sine and cosine of each element in a vector multiplied by pi. [`tan(_:)`](/documentation/simd/tan(_:)-5zsp2) Returns the tangent of each element in a vector. [`tanpi(_:)`](/documentation/simd/tanpi(_:)-54qo6) Returns the tangent of each element in a vector multiplied by pi. [`acos`](/documentation/simd/acos) Returns the arccosine of each element in a vector. [`asin`](/documentation/simd/asin) Returns the arcsine of each element in a vector. [`atan`](/documentation/simd/atan) Returns the arctangent of each element in a vector. [`atan2`](/documentation/simd/atan2) Returns the arctangent of each pair of corresponding elements in two vectors. [`cos`](/documentation/simd/cos) Returns the cosine of each element in a vector. [`cospi`](/documentation/simd/cospi) Returns the cosine of each element in a vector multiplied by pi. [`sin`](/documentation/simd/sin) Returns the sine of each element in a vector. [`sinpi`](/documentation/simd/sinpi) Returns the sine of each element in a vector multiplied by pi. [`tan`](/documentation/simd/tan) Returns the tangent of each element in a vector. [`tanpi`](/documentation/simd/tanpi) Returns the tangent of each element in a vector multiplied by pi. ### Classification Functions [`isfinite(_:)`](/documentation/simd/isfinite(_:)-1870d) Returns true for each element that is finite in a vector. [`isinf(_:)`](/documentation/simd/isinf(_:)-4gutc) Returns true for each element that is infinite in a vector. [`isnan(_:)`](/documentation/simd/isnan(_:)-94v5c) Returns true for each element that is not a number (NaN) in a vector. [`isnormal(_:)`](/documentation/simd/isnormal(_:)-35fxl) Returns true for each element that is normal in a vector. ### Alternative Type Alias [`vector_double4`](/documentation/simd/vector_double4) [`double4`](/documentation/simd/double4) --- Copyright © 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)