This is documentation for Mathematica 6, which was
based on an earlier version of the Wolfram Language.
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ArrayFlatten

ArrayFlatten[{{m11, m12, ...}, {m21, m22, ...}, ...}]
creates a single flattened matrix from a matrix of matrices m_(i​j).
ArrayFlatten[a, r]
flattens out r pairs of levels in the array a.
  • ArrayFlatten requires that the blocks it flattens have dimensions that fit together.
  • ArrayFlatten can be used to form block matrices from arrays of blocks.
  • For a matrix of matrices, ArrayFlatten[a] yields a matrix whose elements are in the same order as in MatrixForm[a].
  • For a tensor with rank 2 r, ArrayFlatten[a, r] gives a tensor with rank r.
  • In ArrayFlatten[{{m11, m12, ...}, {m21, m22, ...}, ...}] all the matrices m_(i​j) in the same row must have the same first dimension, and matrices m_(i​j) in the same column must have the same second dimension.
  • In general, in ArrayFlatten[a, r], all the k^(th) dimensions of a[[i_1,i_2,…,i_r]] must be equal for each possible value of i_k.
  • Elements at level r whose array depth is less than r are treated as scalars, and are replicated to fill out a rank r array of the appropriate dimensions.
New in 6