repelem

Repeat copies of array elements

Syntax

u = repelem(v,n)

B = repelem(A,r1,...,rN)

Description

u = repelem(v,n), where v is a scalar or vector, returns a vector of repeated elements of v.

• If n is a scalar, then each element of v is repeated n times. The length of u is length(v)*n.

• If n is a vector, then it must be the same length as v. Each element of n specifies the number of times to repeat the corresponding element of v.

This syntax is not supported for table input.

B = repelem(A,r1,...,rN) returns an array with each element of A repeated according to r1,...,rN. Each r1,...,rN must either be a scalar or a vector with the same length as A in the corresponding dimension. For example, if A is a matrix, repelem(A,2,3) returns a matrix containing a 2-by-3 block of each element of A.

Examples

Repeat Vector Elements

Create a vector and repeat each of its elements three times into a new vector.

v = [1 2 3 4];
u = repelem(v,3)

u = 1×12

     1     1     1     2     2     2     3     3     3     4     4     4

Repeat the first two elements of v twice and the last two elements three times.

u = repelem(v,[2 2 3 3])

u = 1×10

     1     1     2     2     3     3     3     4     4     4

Repeat Matrix Elements

Create a matrix and repeat each element into a 3-by-2 block of a new matrix.

A = [1 2; 3 4]

A = 2×2

     1     2
     3     4

B = repelem(A,3,2)

B = 6×4

     1     1     2     2
     1     1     2     2
     1     1     2     2
     3     3     4     4
     3     3     4     4
     3     3     4     4

Repeat Matrix Columns

Create a matrix and copy its columns into a new array, repeating the first column twice and second column three times.

A = [1 2; 3 4]

A = 2×2

     1     2
     3     4

B = repelem(A,1,[2 3])

B = 2×5

     1     1     2     2     2
     3     3     4     4     4

Input Arguments

v — Input element

scalar | vector

Input element, specified as a scalar or a vector.

Data Types: single | double | int8 | int16 | int32 | int64 | uint8 | uint16 | uint32 | uint64 | logical | char | string | struct | table | cell | datetime | duration
Complex Number Support: Yes

n — Number of times to repeat each element

scalar | vector

Number of times to repeat each element, specified as a scalar or a vector. If n is a scalar, then all elements of v are repeated n times. If n is a vector, then each element of n specifies the number of times to repeat the corresponding element of v. In either case, n must be integer-valued.

Data Types: single | double | int8 | int16 | int32 | int64 | uint8 | uint16 | uint32 | uint64

A — Input array

matrix | multidimensional array

Input array, specified as a matrix or multidimensional array.

Data Types: single | double | int8 | int16 | int32 | int64 | uint8 | uint16 | uint32 | uint64 | logical | char | struct | table | cell | datetime | duration
Complex Number Support: Yes

r1,...,rN — Repetition factors for each dimension (as separate arguments)

scalars | vectors

Repetition factors for each dimension, specified as separate arguments of integer-valued scalars or vectors. If A is a table, each repetition factor must be a scalar.

Data Types: single | double | int8 | int16 | int32 | int64 | uint8 | uint16 | uint32 | uint64

Output Arguments

u — Output vector

vector

Output vector. If v is a row vector or scalar, u is a row vector. If v is a column vector, u is also a column vector.

Data Types: single | double | int8 | int16 | int32 | int64 | uint8 | uint16 | uint32 | uint64 | logical | char | string | struct | table | cell | datetime | duration

B — Output array

matrix | multidimensional array

Output array, returned as a matrix or multidimensional array.

Data Types: single | double | int8 | int16 | int32 | int64 | uint8 | uint16 | uint32 | uint64 | logical | char | string | struct | table | cell | datetime | duration

Extended Capabilities

Tall Arrays

Calculate with arrays that have more rows than fit in memory.

This function supports tall arrays with the limitations:

• The two-input syntax is not supported.

• The replication factor in the first dimension must be 1. For example, repelem(TA,1,n,p,...).

For more information, see Tall Arrays.

C/C++ Code Generation

Generate C and C++ code using MATLAB® Coder™.

Usage notes and limitations:

• The input must be a vector or matrix. The input cannot be a multidimensional array.

GPU Code Generation

Generate CUDA® code for NVIDIA® GPUs using GPU Coder™.

Usage notes and limitations:

• The input must be a vector or matrix. The input cannot be a multidimensional array.

GPU Arrays

Accelerate code by running on a graphics processing unit (GPU) using Parallel Computing Toolbox™.

This function fully supports GPU arrays. For more information, see Run MATLAB Functions on a GPU (Parallel Computing Toolbox).

Distributed Arrays

Partition large arrays across the combined memory of your cluster using Parallel Computing Toolbox™.

This function fully supports distributed arrays. For more information, see Run MATLAB Functions with Distributed Arrays (Parallel Computing Toolbox).