title: how to plot 2D intensity plot in matplotlib?
body: <p>I have an Nx3 array which stores the values in N coordinates. The first and second column correspond to x and y coordinate respectively, and the third column represents the value at that coordinates. I want to plot a 2D intensity plot, what's the best way to do it?</p>
  
  <p>If the coordinates are evenly spaced, then I can use <code>meshgrid</code> and then use <code>imshow</code>, but in my data the coordinates are not evenly spaced. Besides, the array is very large N~100000, and the values (third column) span several orders of magnitude (so I should be using a logplot?). What's the best way to plot such a graph?</p>