title: Set max and min values of a matrix
body: <p>I have a matrix 640-by-480 where each element has data. I want to set the values of the element to zero where the original values are not between two numbers. For example, <code>A</code> is a 640-by-480 matrix. For the <code>i</code>-th element <code>A(i)</code>, if the value of <code>A(i)</code> is between <code>10</code> and <code>20</code> leave it, if not then set <code>A(i)=0</code>. Could anyone suggest a simple way instead of using loops?</p>