# simd_double2x4 A matrix of two columns and four rows that contains double-precision values. ``` struct simd_double2x4 ``` ## Topics ### Initializers [`init()`](/documentation/simd/simd_double2x4/init()) Creates a new matrix with uninitialized memory. [`init(_:)`](/documentation/simd/simd_double2x4/init(_:)-71dee) Creates a new matrix with the specified scalar value on the main diagonal. [`init(diagonal:)`](/documentation/simd/simd_double2x4/init(diagonal:)) Creates a new matrix with the specified vector on the main diagonal. [`init(_:)`](/documentation/simd/simd_double2x4/init(_:)-6lqav) Creates a new matrix from an array. [`init(_:_:)`](/documentation/simd/simd_double2x4/init(_:_:)) Creates a new matrix with the specified vectors as columns. [`init(columns:)`](/documentation/simd/simd_double2x4/init(columns:)) Creates a new matrix with the specified columns. [`init(rows:)`](/documentation/simd/simd_double2x4/init(rows:)) Creates a new matrix with the specified rows. ### Matrix Properties [`transpose`](/documentation/simd/simd_double2x4/transpose) The transpose of the matrix. [`columns`](/documentation/simd/simd_double2x4/columns) The columns of the matrix. ### Matrix Creation Functions [`simd_matrix(_:_:)`](/documentation/simd/simd_matrix(_:_:)-7hafe) Returns a new matrix with the specified columns. [`simd_matrix_from_rows(_:_:_:_:)`](/documentation/simd/simd_matrix_from_rows(_:_:_:_:)-851r7) Returns a new matrix with the specified rows. [`matrix_from_rows(_:_:_:_:)`](/documentation/simd/matrix_from_rows(_:_:_:_:)-897qw) Returns a new matrix with the specified rows. ### Math Functions [`simd_add`](/documentation/simd/simd_add-1e1xc) Returns the sum of two matrices. [`simd_sub`](/documentation/simd/simd_sub-75iiq) Returns the difference of two matrices. [`matrix_scale`](/documentation/simd/matrix_scale-1fgte) Returns the product of a scalar value and a matrix. ### Matrix-Scalar Multiplication Functions [`simd_mul`](/documentation/simd/simd_mul-7g2eo) Returns the product of a scalar value and a 2 x 4 matrix. ### Matrix-Vector Multiplication Functions [`simd_mul`](/documentation/simd/simd_mul-43dfj) Returns the product of a four-element vector and a 2 x 4 matrix. [`matrix_multiply`](/documentation/simd/matrix_multiply-4dr8s) Returns the product of a four-element vector and a 2 x 4 matrix. [`simd_mul`](/documentation/simd/simd_mul-6ub7w) Returns the product of a 2 x 4 matrix and a two-element vector. [`matrix_multiply`](/documentation/simd/matrix_multiply-7vmen) Returns the product of a 2 x 4 matrix and a two-element vector. ### Matrix-Matrix Multiplication Functions [`simd_mul`](/documentation/simd/simd_mul-3mmg5) Returns the product of a 2 x 4 matrix and a 2 x 2 matrix. [`matrix_multiply`](/documentation/simd/matrix_multiply-1k4mc) Returns the product of a 2 x 4 matrix and a 2 x 2 matrix. [`simd_mul`](/documentation/simd/simd_mul-6qmy5) Returns the product of a 3 x 4 matrix and a 2 x 3 matrix. [`matrix_multiply`](/documentation/simd/matrix_multiply-tcz1) Returns the product of a 3 x 4 matrix and a 2 x 3 matrix. [`simd_mul`](/documentation/simd/simd_mul-63k1v) Returns the product of a 4 x 4 matrix and a 2 x 4 matrix. [`matrix_multiply`](/documentation/simd/matrix_multiply-30ogt) Returns the product of a 4 x 4 matrix and a 2 x 4 matrix. ### Equality Functions [`simd_equal`](/documentation/simd/simd_equal-3xz83) Returns true if every element in a matrix is exactly equal to the corresponding element in a second matrix. [`simd_almost_equal_elements`](/documentation/simd/simd_almost_equal_elements-59py1) Returns true if every element in a matrix is within a specified tolerance to the corresponding element in a second matrix. [`simd_almost_equal_elements_relative`](/documentation/simd/simd_almost_equal_elements_relative-8187e) Returns true if every element in a matrix is within a specified double-precision relative tolerance to the corresponding element in a second matrix. ### Linear Combination Function [`simd_linear_combination`](/documentation/simd/simd_linear_combination-gtsr) ### Transpose Function [`simd_transpose`](/documentation/simd/simd_transpose-847r1) ### Element Access [`subscript(_:)`](/documentation/simd/simd_double2x4/subscript(_:)) Accesses the column at the specified position. [`subscript(_:_:)`](/documentation/simd/simd_double2x4/subscript(_:_:)) Accesses the element at the specified position. ### Type Aliases [`double2x4`](/documentation/simd/double2x4) A type alias for a double-precision 2 x 4 matrix. [`matrix_double2x4`](/documentation/simd/matrix_double2x4) A type alias for a double-precision 2 x 4 matrix. ### Deprecated Symbols [`matrix_equal(_:_:)`](/documentation/simd/matrix_equal(_:_:)-1dcgx) Returns true if every element in a matrix is exactly equal to the corresponding element in a second matrix, and otherwise returns false. [`matrix_from_columns(_:_:)`](/documentation/simd/matrix_from_columns(_:_:)-9q8xb) Returns a new matrix with the specified columns. [`matrix_transpose(_:)`](/documentation/simd/matrix_transpose(_:)-bpqg) Returns the transpose of a matrix. [`init(_:)`](/documentation/simd/simd_double2x4/init(_:)-6ssjo) Creates a new matrix with the specified matrix. [`cmatrix`](/documentation/simd/simd_double2x4/cmatrix) Creates a new matrix with the specified matrix. --- 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)