title: MATLAB - Meaning of guassian distribution data. (in Neural Network)
body: <p>I'm a newbie to MATLAB and now I'm trying to create a 2-d gaussian distribute data to train my neural network. I just found the code on the official document.</p>
  
  <pre><code>mu = [0 0];
  Sigma = [.25 .3; .3 1];
  x1 = -3:.2:3; x2 = -3:.2:3;
  [X1,X2] = meshgrid(x1,x2);
  F = mvnpdf([X1(:) X2(:)],mu,Sigma);
  </code></pre>
  
  <p>I know "mu" is average of the data. Sigma is something related to 
  Standard deviation. But I just don't get what is the idea of mesgrid and the interval(x1,x2). And the Geometric meaning of these code.</p>
  
  <p>Also, can someone explain me why is guassian distribution so important in machine learning and data science? Cause all the course keep saying and saying this term. </p>