       Re: Combining Matrices

• To: mathgroup at smc.vnet.net
• Subject: [mg65061] Re: Combining Matrices
• From: Jean-Marc Gulliet <jeanmarc.gulliet at gmail.com>
• Date: Sun, 12 Mar 2006 23:59:41 -0500 (EST)
• Organization: The Open University, Milton Keynes, UK
• References: <duudan\$ht1\$1@smc.vnet.net>
• Sender: owner-wri-mathgroup at wolfram.com

```Gregory Lypny wrote:
> Hello Everyone,
>
> I'm trying to figure out how to combine an n x p matrix and an n x q
> matrix to form an n x (p + q) matrix.  I found one way, shown in the
> second last line of the code below, but I have no idea why it works,
> and I'm wondering whether there is a more direct way.  The example
> takes 3 x 4 matrix A and combines it with 3 x 2 matrix B to form 3 x
> 6 matrix X.
>
> Any thoughts would be most appreciated.
>
> 	Gregory
>
> Clear[X]
> n = 3; p = 4; q = 2;
> A = Array[a, {n, p}];
> B = Array[b, {n, q}];
> (X = Transpose[Flatten[{{Transpose[A], Transpose[B]}}, 2]]) //
> MatrixForm
> Dimensions[X]
>
Hi Gregory,

Clear[X]
n = 3; p = 4; q = 2;
A = Array[a, {n, p}];
B = Array[b, {n, q}];