title: Filling a 2D Array (a Matrix)
body: <p>Consider, for instance, the following formula:</p>
  <p><span class="math-container">$$f_{nm}(x) = \sin(n \ m \ x^2/\pi)$$</span></p>
  <p>where <span class="math-container">$n$</span> and <span class="math-container">$m$</span> both are integers <span class="math-container">$\in [1,4]$</span>. Forming a <strong>matrix</strong> with this information would result in:</p>
  <p><span class="math-container">$$\mathbf{F} =  \begin{pmatrix}\ f_{11} &amp; f_{12} &amp; f_{13} &amp; f_{14} \\ f_{21} &amp; f_{22} &amp; f_{23} &amp; f_{24} \\ f_{31} &amp; f_{32} &amp; f_{33} &amp; f_{34} \\ f_{41} &amp;f_{42}&amp;f_{43}&amp;f_{44}\end{pmatrix}$$</span></p>
  <p>How to create such a <span class="math-container">$4\times4$</span> matrix in <strong>Python</strong> and fill it with the provided formula for a given <span class="math-container">$x$</span> please. I know this question may be off-topic here, but the <span class="math-container">$LaTeX$</span> style of the equations did not work for me in the StackOverflow, that is why posted it here.</p>