# simd_double3 A vector of three 64-bit floating-point elements. ``` typealias simd_double3 = SIMD3 ``` ## Topics ### Functions to Create Three-Element Vectors From Other Vectors [`simd_make_double3(_:)`](/documentation/simd/simd_make_double3(_:)-5ti92) Returns a new vector from the specified two-element vector, and other elements set to zero. [`simd_make_double3(_:)`](/documentation/simd/simd_make_double3(_:)-5qigh) Returns a new vector from the specified vector. [`simd_make_double3(_:)`](/documentation/simd/simd_make_double3(_:)-5zuas) Returns a new vector by truncating the specified four-element vector. [`simd_make_double3(_:)`](/documentation/simd/simd_make_double3(_:)-4tl5k) Returns a new vector by truncating the specified eight-element vector. [`simd_make_double3_undef(_:)`](/documentation/simd/simd_make_double3_undef(_:)-95a07) Returns a new vector from the specified two-element vector, and other elements undefined. ### Functions to Create Three-Element Vectors From Scalar Values [`simd_make_double3(_:)`](/documentation/simd/simd_make_double3(_:)-3qbde) Returns a new vector with the first element set to a scalar value, and other elements set to zero. [`simd_make_double3(_:_:_:)`](/documentation/simd/simd_make_double3(_:_:_:)) Returns a new vector from the specified scalar values. [`vector3`](/documentation/simd/vector3-kp2l) Returns a new vector from the specified scalar values. [`simd_make_double3_undef(_:)`](/documentation/simd/simd_make_double3_undef(_:)-38cg2) Returns a new vector with the first element set to a scalar value, and other elements undefined. ### Functions to Create Three-Element Vectors From Combinations of Vectors and Scalar Values [`simd_make_double3(_:_:)`](/documentation/simd/simd_make_double3(_:_:)-2va6) Returns a new vector from a scalar value and a vector. [`simd_make_double3(_:_:)`](/documentation/simd/simd_make_double3(_:_:)-3b3z3) Returns a new vector from a vector and a scalar value. [`vector3`](/documentation/simd/vector3-2regp) Returns a new vector from a vector and a scalar value. ### Functions to Create Three-Element Vectors From Vectors of Other Types [`simd_double`](/documentation/simd/simd_double-50ppx) Returns a new vector from the specified vector of 8-bit, signed-integer elements. [`simd_double`](/documentation/simd/simd_double-50fw5) Returns a new vector from the specified vector of 8-bit, unsigned-integer elements. [`simd_double`](/documentation/simd/simd_double-50kxh) Returns a new vector from the specified vector of 16-bit, signed-integer elements. [`simd_double`](/documentation/simd/simd_double-50at1) Returns a new vector from the specified vector of 16-bit, unsigned-integer elements. [`simd_double`](/documentation/simd/simd_double-50rjx) Returns a new vector from the specified vector of 32-bit, signed-integer elements. [`simd_double`](/documentation/simd/simd_double-50hml) Returns a new vector from the specified vector of 32-bit, unsigned-integer elements. [`simd_double`](/documentation/simd/simd_double-50shr) Returns a new vector from the specified vector of 64-bit, signed-integer elements. [`simd_double`](/documentation/simd/simd_double-50irj) Returns a new vector from the specified vector of 64-bit, unsigned-integer elements. [`simd_double`](/documentation/simd/simd_double-50gn7) Returns a new vector from the specified vector of 32-bit, floating-point elements. [`simd_double`](/documentation/simd/simd_double-50g0v) Returns a new vector from the specified vector of 64-bit, floating-point elements. ### Common Functions [`simd_abs(_:)`](/documentation/simd/simd_abs(_:)-8db3x) Returns the absolute value of each element in a vector. [`abs(_:)`](/documentation/simd/abs(_:)-8miv) Returns the absolute value of each element in a vector. [`simd_clamp(_:_:_:)`](/documentation/simd/simd_clamp(_:_:_:)-2jao) Returns each element in a vector clamped to a specified range. [`clamp(_:min:max:)`](/documentation/simd/clamp(_:min:max:)-5otf7) Returns each element in a vector clamped to a specified range. [`clamp(_:min:max:)`](/documentation/simd/clamp(_:min:max:)-6m2so) Returns each element in a vector clamped to a specified range. [`simd_equal(_:_:)`](/documentation/simd/simd_equal(_:_:)-4v2cb) Returns true if every element in a vector is exactly equal to the corresponding element in a second vector, and otherwise returns false. [`simd_fract(_:)`](/documentation/simd/simd_fract(_:)-47n4w) Returns the fractional part of each element in a vector. [`fract(_:)`](/documentation/simd/fract(_:)-swov) Returns the fractional part of each element in a vector. [`simd_sign(_:)`](/documentation/simd/simd_sign(_:)-6goju) Returns the sign of each element in a vector. [`sign(_:)`](/documentation/simd/sign(_:)-2qtea) Returns the sign of each element in a vector. [`simd_step(_:_:)`](/documentation/simd/simd_step(_:_:)-2gbx7) Returns zero for each element in a vector less than a specified edge, and otherwise returns one. [`step(_:edge:)`](/documentation/simd/step(_:edge:)-4azct) 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(_:)-2v7l1) Returns the sum of all elements in a vector. [`reduce_add(_:)`](/documentation/simd/reduce_add(_:)-3112d) Returns the sum of all elements in a vector. [`simd_reduce_max(_:)`](/documentation/simd/simd_reduce_max(_:)-4gytr) Returns the maximum value in a vector. [`reduce_max(_:)`](/documentation/simd/reduce_max(_:)-96cb3) Returns the maximum value in a vector. [`simd_reduce_min(_:)`](/documentation/simd/simd_reduce_min(_:)-46by3) Returns the miniumum value in a vector. [`reduce_min(_:)`](/documentation/simd/reduce_min(_:)-9g9a6) Returns the miniumum value in a vector. ### Interpolation Functions [`simd_mix(_:_:_:)`](/documentation/simd/simd_mix(_:_:_:)-46dv1) Returns an element-wise linearly interpolated value between two vectors. [`mix(_:_:t:)`](/documentation/simd/mix(_:_:t:)-1dp7m) Returns an element-wise linearly interpolated value between two vectors. [`mix(_:_:t:)`](/documentation/simd/mix(_:_:t:)-5ifg3) Returns an element-wise linearly interpolated value between two vectors. [`simd_smoothstep(_:_:_:)`](/documentation/simd/simd_smoothstep(_:_:_:)-9hwr9) Returns an element-wise smoothly interpolated value between two vectors. [`smoothstep(_:edge0:edge1:)`](/documentation/simd/smoothstep(_:edge0:edge1:)-5ih1o) Returns an element-wise smoothly interpolated value between two vectors. ### Extrema Functions [`simd_min(_:_:)`](/documentation/simd/simd_min(_:_:)-5xqg7) Returns the minimum value of each element in a vector. [`min(_:_:)`](/documentation/simd/min(_:_:)-7hm19) Returns the minimum value of each element in a vector. [`min(_:_:)`](/documentation/simd/min(_:_:)-32b0w) Returns the minimum value of each element in a vector. [`fmin(_:_:)`](/documentation/simd/fmin(_:_:)-6p9y) Returns the minimum value of each element in a vector. [`simd_max(_:_:)`](/documentation/simd/simd_max(_:_:)-6ykq4) Returns the maximum value of each element in a vector. [`max(_:_:)`](/documentation/simd/max(_:_:)-1mzkc) Returns the maximum value of each element in a vector. [`max(_:_:)`](/documentation/simd/max(_:_:)-9e6ry) Returns the maximum value of each element in a vector. [`fmax(_:_:)`](/documentation/simd/fmax(_:_:)-4pce8) Returns the maximum value of each element in a vector. ### Reciprocal and Reciprocal Square Root Functions [`simd_recip(_:)`](/documentation/simd/simd_recip(_:)-8jzqn) Returns the reciprocal of each element in a vector. [`recip(_:)`](/documentation/simd/recip(_:)-6uvj7) Returns the reciprocal of each element in a vector. [`simd_rsqrt(_:)`](/documentation/simd/simd_rsqrt(_:)-rhpf) Returns the reciprocal square root of each element in a vector. [`rsqrt(_:)`](/documentation/simd/rsqrt(_:)-6298y) Returns the reciprocal square root of each element in a vector. [`simd_precise_recip(_:)`](/documentation/simd/simd_precise_recip(_:)-61i77) Returns the precise reciprocal of each element in a vector. [`simd_precise_rsqrt(_:)`](/documentation/simd/simd_precise_rsqrt(_:)-zrh9) Returns the precise reciprocal square root of each element in a vector. [`simd_fast_recip(_:)`](/documentation/simd/simd_fast_recip(_:)-ogui) Returns the fast reciprocal of each element in a vector. [`simd_fast_rsqrt(_:)`](/documentation/simd/simd_fast_rsqrt(_:)-80w49) Returns the fast reciprocal square root of each element in a vector. ### Exponential and Logarithmic Functions [`exp(_:)`](/documentation/simd/exp(_:)-zash) Returns *e* raised to the power of each element in a vector. [`exp2(_:)`](/documentation/simd/exp2(_:)-26tvo) Returns 2 raised to the power of each element in a vector. [`exp10(_:)`](/documentation/simd/exp10(_:)-88dd5) Returns 10 raised to the power of each element in a vector. [`expm1(_:)`](/documentation/simd/expm1(_:)-2ag4r) Returns *eˣ-1* for each element in a vector. [`log(_:)`](/documentation/simd/log(_:)-70ujd) Returns the natural logarithm of each element in a vector. [`log2(_:)`](/documentation/simd/log2(_:)-3p8ex) Returns the base 2 logarithm of each element in a vector. [`log10(_:)`](/documentation/simd/log10(_:)-1eshe) Returns the base 10 logarithm of each element in a vector. [`log1p(_:)`](/documentation/simd/log1p(_:)-50npd) 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_cross`](/documentation/simd/simd_cross-27rm0) Returns the cross product of two vectors. [`cross(_:_:)`](/documentation/simd/cross(_:_:)-7sd7t) Returns the cross product of two vectors. [`simd_dot`](/documentation/simd/simd_dot-8l0kd) Returns the dot product of two vectors. [`dot(_:_:)`](/documentation/simd/dot(_:_:)-2sdb) Returns the dot product of two vectors. [`simd_insphere`](/documentation/simd/simd_insphere-88pzx) Tests if a double-precision point lies inside, on, or outside a sphere. [`simd_normalize`](/documentation/simd/simd_normalize-9c477) Returns a vector pointing in the same direction of the supplied vector, with a length of 1. [`normalize(_:)`](/documentation/simd/normalize(_:)-29n8k) 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-d0e) Returns the fast normalized vector. [`simd_precise_normalize`](/documentation/simd/simd_precise_normalize-4z8q1) Returns the precise normalized vector. [`simd_orient`](/documentation/simd/simd_orient-4dorr) Tests the orientation of the three supplied vectors. [`simd_orient`](/documentation/simd/simd_orient-5pahm) Tests the orientation of the four supplied vectors. [`simd_project`](/documentation/simd/simd_project-7mlzt) Returns the first vector projected onto the second vector. [`project(_:_:)`](/documentation/simd/project(_:_:)-9jlig) Returns the first vector projected onto the second vector. [`simd_fast_project`](/documentation/simd/simd_fast_project-54ecd) Returns the fast projected vector. [`simd_precise_project`](/documentation/simd/simd_precise_project-3cfbv) Returns the precise projected vector. [`simd_reflect`](/documentation/simd/simd_reflect-26oex) Returns the reflection direction of an incident vector and a unit normal vector. [`reflect(_:n:)`](/documentation/simd/reflect(_:n:)-1vw0n) Returns the reflection direction of an incident vector and a unit normal vector. [`simd_refract`](/documentation/simd/simd_refract-8ogip) 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:)-13wsy) 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-xf5y) Returns the sum of the absolute values of a vector. [`norm_one(_:)`](/documentation/simd/norm_one(_:)-mrh) Returns the sum of the absolute values of a vector. [`simd_norm_inf`](/documentation/simd/simd_norm_inf-94bsb) Returns the maximum absolute value of a vector. [`norm_inf(_:)`](/documentation/simd/norm_inf(_:)-7ga8i) Returns the maximum absolute value of a vector. ### Length and Distance Functions [`simd_length`](/documentation/simd/simd_length-3r7wy) Returns the length of a vector. [`length(_:)`](/documentation/simd/length(_:)-907xq) Returns the length of a vector. [`simd_fast_length`](/documentation/simd/simd_fast_length-56j8x) Returns the fast length of a vector. [`simd_precise_length`](/documentation/simd/simd_precise_length-7aygj) Returns the precise length of a vector. [`simd_length_squared`](/documentation/simd/simd_length_squared-3hijo) Returns the square of the length of a vector. [`length_squared(_:)`](/documentation/simd/length_squared(_:)-620zs) Returns the square of the length of a vector. [`simd_distance`](/documentation/simd/simd_distance-30257) Returns the distance between two vectors. [`distance(_:_:)`](/documentation/simd/distance(_:_:)-57zfj) Returns the distance between two vectors. [`simd_fast_distance`](/documentation/simd/simd_fast_distance-9625l) Returns the fast distance between two vectors. [`simd_precise_distance`](/documentation/simd/simd_precise_distance-274w4) Returns the precise distance between two vectors. [`simd_distance_squared`](/documentation/simd/simd_distance_squared-89twb) Returns the square of the distance between two vectors. [`distance_squared(_:_:)`](/documentation/simd/distance_squared(_:_:)-4erc0) ### Hyperbolic Functions [`acosh(_:)`](/documentation/simd/acosh(_:)-1e4qf) Returns the inverse hyperbolic cosine of each element in a vector. [`asinh(_:)`](/documentation/simd/asinh(_:)-8b3vg) Returns the inverse hyperbolic sine of each element in a vector. [`atanh(_:)`](/documentation/simd/atanh(_:)-7z6qz) Returns the inverse hyperbolic tangent of each element in a vector. [`cosh(_:)`](/documentation/simd/cosh(_:)-6f3bc) Returns the hyperbolic cosine of each element in a vector. [`sinh(_:)`](/documentation/simd/sinh(_:)-6glq8) Returns the hyperbolic sine of each element in a vector. [`tanh(_:)`](/documentation/simd/tanh(_:)-4b44y) 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(_:_:_:)-1aiih) 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(_:_:_:)-mtv1) 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(_:)-38h14) Returns the cube root of each element in a vector. [`ceil(_:)`](/documentation/simd/ceil(_:)-72yci) Returns the ceiling of each element in a vector. [`erf(_:)`](/documentation/simd/erf(_:)-8eer2) Returns the error function for each element in a vector. [`erfc(_:)`](/documentation/simd/erfc(_:)-7ux6y) Returns the complementary error function for each element in a vector. [`floor(_:)`](/documentation/simd/floor(_:)-262rp) Returns the floor of each element in a vector. [`fma(_:_:_:)`](/documentation/simd/fma(_:_:_:)-6w3jf) Returns the multiply-add result for corresponding elements in three vectors. [`fmod(_:_:)`](/documentation/simd/fmod(_:_:)-16oie) Returns the modulus after dividing each element in a vector by the corresponding element in a second vector. [`hypot(_:_:)`](/documentation/simd/hypot(_:_:)-5z7ry) 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(_:)-4lks7) Returns the natural logarithm of the absolute value of the gamma function of each element in a vector. [`nextafter(_:_:)`](/documentation/simd/nextafter(_:_:)-7qi1e) 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(_:_:)-6hgod) Returns each element in a vector raised to the power of the corresponding element in a second vector. [`remainder(_:_:)`](/documentation/simd/remainder(_:_:)-28w7v) 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(_:)-3e7l9) 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. [`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(_:_:_:)-74qpk) Returns the multiply-add result for corresponding elements in three vectors. [`tgamma(_:)`](/documentation/simd/tgamma(_:)-98alm) Returns the gamma function for each element in a vector. [`trunc(_:)`](/documentation/simd/trunc(_:)-4p8mg) 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(_:)-76i0e) Returns the arccosine of each element in a vector. [`asin(_:)`](/documentation/simd/asin(_:)-g6mp) Returns the arcsine of each element in a vector. [`atan(_:)`](/documentation/simd/atan(_:)-2h77h) Returns the arctangent of each element in a vector. [`atan2(_:_:)`](/documentation/simd/atan2(_:_:)-1zx4a) Returns the arctangent of each pair of corresponding elements in two vectors. [`cos(_:)`](/documentation/simd/cos(_:)-9hw4a) Returns the cosine of each element in a vector. [`cospi(_:)`](/documentation/simd/cospi(_:)-471sg) Returns the cosine of each element in a vector multiplied by pi. [`sin(_:)`](/documentation/simd/sin(_:)-5dnnn) Returns the sine of each element in a vector. [`sinpi(_:)`](/documentation/simd/sinpi(_:)-291vx) Returns the sine of each element in a vector multiplied by pi. [`sincos(_:)`](/documentation/simd/sincos(_:)-6572x) Returns the sine and cosine of each element in a vector. [`sincospi(_:)`](/documentation/simd/sincospi(_:)-2t5q7) Returns the sine and cosine of each element in a vector multiplied by pi. [`tan(_:)`](/documentation/simd/tan(_:)-2tvur) Returns the tangent of each element in a vector. [`tanpi(_:)`](/documentation/simd/tanpi(_:)-42odv) 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. [`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(_:)-1s3ji) Returns true for each element that is finite in a vector. [`isinf(_:)`](/documentation/simd/isinf(_:)-6gve5) Returns true for each element that is infinite in a vector. [`isnan(_:)`](/documentation/simd/isnan(_:)-6l7v3) Returns true for each element that is not a number (NaN) in a vector. [`isnormal(_:)`](/documentation/simd/isnormal(_:)-8k36k) Returns true for each element that is normal in a vector. ### Alternative Type Alias [`vector_double3`](/documentation/simd/vector_double3) [`double3`](/documentation/simd/double3) --- 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)