I have a matrix 'mat' and I would like to stack it k times

$$\begin{pmatrix} mat \\ mat \\ mat \\ mat \\ mat \\ \vdots \end{pmatrix}$$

such that the result is also a matrix. I tried Join and ArrayFlatten but it did not seem to work. Especially the fact that k is supposed to stay arbitrary makes it really difficult for me.


2 Answers 2

mat = Array[a, {3, 3}];

k = 5;
stacked = ArrayFlatten[ConstantArray[{mat}, k]]

Row[MatrixForm /@ {mat, stacked}, Spacer[10]]

enter image description here


Array[mat &, k, 1, Join] == 
Join @@ ConstantArray[mat, k] ==
Flatten[ConstantArray[mat, k], 1] == 
ArrayFlatten[ConstantArray[mat, k], 1] ==



Using the same mat and k as those in @kglr 's post, here is another option:

KroneckerProduct[ConstantArray[1, k], mat]

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.