Matrix notation for vector stacking

hadron23
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Hello,

I have a row vector defined as,

X=\{x_1,x_2,\ldots,x_L\}
I wish to "stack" this vector vertically, a total of N times, such that the result is a matrix of the form,

\begin{align}Y = \left[ \begin{array}{cccc}<br /> x_1 &amp; x_2 &amp; \ldots &amp; x_L \\<br /> x_1 &amp; x_2 &amp; \ldots &amp; x_L \\<br /> . &amp; . &amp; . &amp; .\\<br /> . &amp; . &amp; . &amp; .\\<br /> . &amp; . &amp; . &amp; .\\<br /> x_1 &amp; x_2 &amp; \ldots &amp; x_L \end{array} \right]<br /> \end{align}
I want to write this in matrix notation, that is, using only vectors and matrices, and not any summations or other operators. I am not sure how to do this cleanly, any help would be greatly appreciated :)

Thank you.
 
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Hi hadron23! :smile:

What about

(1,1,...,1)^T.(x_1,...,x_n)
 
In hindsight, this is stupidly simple. Thanks!
 

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