Matlab Array - Concatenating

• All operations below return a new array.

General Concatenation

• Each input array’s size must match the chosen concatenation axis, otherwise an error is raised.

• Horizontal concatenation

  • [A1 A2 ...]
  • Function horzcat(A1,A2,...)

• Vertical concatenation

  • [A1; A2; ...]
  • Function vertcat(A1,A2,...)

• Concatenation along an arbitrary dimension

  • Function cat(dim,A1,A2,...) concatenates A1, …, An along dimension dim
    • dim may exceed the input arrays’ dimensionality, in which case a higher-dimensional array is created; any unspecified intermediate dimensions are filled with size 1

• Horizontal concatenation corresponds to dim = 2, and vertical concatenation to dim = 1.

Block Operations

The functions below take matrices as inputs and treat them as building blocks of a larger array:

• Block-diagonal: blkdiag
• Tile a block: repmat
• Kronecker Tensor Product kron(A,B)