Get access to the first row of a list in R
<p>Consider a list in R, for example</p>

<pre><code>A=list()
A[[1]]=c(1,2)
A[[2]]=c(3,4)
</code></pre>

<p>Is it possible to return a vector which gives the first element of each entry of the list (here <code>c(1,3)</code>)?</p>

<p>And as a extension: What, if the elements of the list are not just vectors but matrices. Is it possible to get the vector that contains the first element of the second row for each matrix?</p>