title: how to use cell value as index
body: <p>I have an row array <code>X</code>, and a cell <code>C = {[1 3 4] [2 6]}</code>. I want to use <code>C</code> as index to get corresponding value from <code>x. The result should be</code>{[x(1) x(3) x(4)] [x(2) x(6)]}<code>. I tried</code>x(C)` but it doesn't work. How can I achieve this?</p>