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matrix - How do I put matrices next to each other?



So I want to be able to put matrices "next to each other", or in other words if I have two matrices $A$ that is $n\times k$ and $B$ that is $n\times m$, I want to be able to create a matrix $C$ that is $n\times (k+m)$ so that the $(k+1)$th column of $C$ is the first column of $B$.


This should be really easy, and in matlab it is (C= [A B]), but I can't figure it out in mathematica




Answer



Like this?


(a = ConstantArray["A", {4, 3}]) // MatrixForm

enter image description here


(b = ConstantArray["B", {4, 4}]) // MatrixForm

enter image description here


Map[Flatten, Transpose[{a, b}]] // MatrixForm


enter image description here


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