text: user762: I have two columns of data, x and y, how can I make a ‘thermodynamic diagram’ with matlab? The z axis is the density value of dots, like below figure.
  
  
  The x-axis is angle, y-axis is distance.
  I want to construct a heatmap like this figure:
  
  user581: A reverse image search on google leads to the exact code used to produce the second image:
  [Xcoarse, Ycoarse] = meshgrid([0 1 2 3], [0 1 2 3]);
  [Xfine, Yfine] = meshgrid(linspace(0,3,3000), linspace(0,3,3000));
  DataCoarse = [ 1 2 4 1; ...
             6 3 5 2; ...
             4 2 1 5; ...
             5 4 2 3];
  DataBicubicFine  = interp2(Xcoarse, Ycoarse, DataCoarse, Xfine, Yfine, 'bicubic');
  figure
  surf(Xfine, Yfine, DataBicubicFine); shading flat; colormap(jet); view(0, 90)
   hold on; plot3(Xcoarse, Ycoarse, 10*ones(size(Xcoarse)), 'k.', 'MarkerSize', 20)
  colorbar
  print -dpng -r300 BicubicInterpolationExample.png 
  
  
original_text: 762: <p>I have two columns of data, x and y, how can I make a ‘thermodynamic diagram’ with matlab? The z axis is the density value of dots, like below figure.
  <a href="https://i.stack.imgur.com/LL0Qw.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/LL0Qw.jpg" alt="enter image description here"></a>
  <a href="https://i.stack.imgur.com/E0Ov7.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/E0Ov7.jpg" alt="enter image description here"></a></p>
  
  <p>The x-axis is angle, y-axis is distance.<a href="https://i.stack.imgur.com/tjBpo.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/tjBpo.png" alt="enter image description here"></a>
  I want to construct a heatmap like this figure:<a href="https://i.stack.imgur.com/Vh8Iz.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/Vh8Iz.jpg" alt="enter image description here"></a></p>
   581: <p>A reverse image search on google leads to the <a href="https://commons.wikimedia.org/wiki/File:BicubicInterpolationExample.png" rel="nofollow noreferrer">exact code</a> used to produce the second image:</p>
  
  <pre><code>[Xcoarse, Ycoarse] = meshgrid([0 1 2 3], [0 1 2 3]);
  [Xfine, Yfine] = meshgrid(linspace(0,3,3000), linspace(0,3,3000));
  DataCoarse = [ 1 2 4 1; ...
             6 3 5 2; ...
             4 2 1 5; ...
             5 4 2 3];
  DataBicubicFine  = interp2(Xcoarse, Ycoarse, DataCoarse, Xfine, Yfine, 'bicubic');
  figure
  surf(Xfine, Yfine, DataBicubicFine); shading flat; colormap(jet); view(0, 90)
   hold on; plot3(Xcoarse, Ycoarse, 10*ones(size(Xcoarse)), 'k.', 'MarkerSize', 20)
  colorbar
  print -dpng -r300 BicubicInterpolationExample.png 
  </code></pre>
  