title: How to plot a group of subplots in fixed axes setting automatically in Matlab?
body: <p>The plotting code is shown as:</p>
  
  <pre><code>figure;
  snr_idx = 1:2:7;
  for n = 1:4
      subplot(2,2,n);    
      ith = snr_idx(n);    
  
      xx_cpd(:,n) = reshape(theta_est_s1(1,ith,:,1), 500,1);
      yy_cpd(:,n) = reshape(theta_est_s1(2,ith,:,1), 500,1);
  
      scatter(xx_cpd(:,n), yy_cpd(:,n), 30, 'o', 'LineWidth', 5e-5)   
  
      grid on
      xlabel('\phi_1 (deg)','fontsize',12)
      ylabel('\phi_2 (deg)','fontsize',12)
      title(['SNR = ',num2str(SNRvec(ith)), 'dB' ])   
  end
  </code></pre>
  
  <p>Where <code>SNRvec</code> is a vector as: [-3  0  3  6  9  12  15].</p>
  
  <p><code>theta_est_s1</code> is a four-dimensional array, the size of <code>theta_est_s1</code> is 2×7×500×3.</p>
  
  <p>Then the resulting figure is shown as following:</p>
  
  <p><img src="https://i.stack.imgur.com/ZLq8g.png" alt="fig1"></p>
  
  <p>However, the contrast between each subplot is not remarkable enough. I want all the subplots have the same axis setting as the first subplot, i.e. when the first subplot is made, the axis is fixed, which is shown as:</p>
  
  <p><img src="https://i.stack.imgur.com/hMADR.png" alt="fig1"></p>
  
  <p>If I use <code>axis([60 70 110 120])</code> command in this example, the resulting figure is correct. Nevertheless, the range of <code>theta_est_s1</code> is not fixed. When the input data is changed, the maximum and minimum of <code>theta_est_s1</code> are changed a lot. Therefore I cannot merely set the axis manually in a direct way.</p>
  
  <p>Is there any method to figure out this issue?</p>
  
  <p>Thanks!</p>