# Write Tensor Product in Matrix Form

I want to write the tensor product A $$\otimes$$ B in matrix form, where$$$$A= \left[ {\begin{array}{cc} 1 & 2 & 3\\ 4 & 5 &6 \\ 7 & 8 &9 \\ \end{array} } \right]$$$$ and B is not specified, in the form$$$$A \otimes B = \left[ {\begin{array}{cc} 1 & 2 & 3\\ 4 & 5 &6 \\ 7 & 8 &9 \\ \end{array} } \right] \otimes B$$$$However, by writing:

TensorProduct[{{1,2,3},{4,5,6},{7,8,9}}, B] //MatrixForm


I obtain the form {{1,2,3},{4,5,6},{7,8,9}} $$\otimes$$ B as an output, which I do not want.

• Is this just for presentation? You could do MapAt[MatrixForm, TensorProduct[{{1, 2, 3},{4, 5, 6}, {7, 8, 9}}, B],1]. You could also do TensorProduct[{{1, 2, 3}, {4, 5, 6}, {7, 8, 9}}, B] //TraditionalForm – flinty Aug 8 '20 at 10:43