Make a matrix from submatrix in R
<p>I need to make a matrix in <code>R</code> with its elements are from matrices I defined before.
For example, I have 4 matrices, </p>

<pre><code>w &lt;- matrix(c(1,2,3,4),2,2)
x &lt;- matrix(c(5,6,7,8),2,2)
y &lt;- matrix(c(9,10,11,12),2,2)
z &lt;- matrix(c(13,14,15,16),2,2)
</code></pre>

<p>Then, the new matrix should be a <code>4X4</code> matrix with <code>w</code> is an <code>[1:2,1:2]</code> element, <code>x</code> is an <code>[1:2,3:4]</code> element, <code>y</code> is an <code>[3:4,1:2]</code> element, and <code>z</code> is an <code>[3:4,3:4]</code> element.</p>

<p>How can I do that quickly?</p>