title: GNUPlot: Plot 4D gridded data
body: <p>I am using GUNPlot to plot a 3D color map (x,y,z,Temp), which should be more like the following one:
  <a href="https://i.stack.imgur.com/BzZpp.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/BzZpp.jpg" alt="enter image description here"></a>
  However, the data I got is not in consecutive sequence. For example, the format of the file is</p>
  
  <pre><code>X(km)        Y(km)       Z(km)       T1
  306.6319    40.4795    359.4912    160.70    
  65.1636    466.8436    48.6078     186.67    
  471.2971    19.4918    47.6832     176.14    
  19.4881    46.7308    471.4173     101.02    
  426.2099    99.7980    180.3663    174.60    
  41.8988    148.1945    448.8270    139.13    
  132.5433    213.1093    402.6409    156.01    
  76.4752    203.1392    422.2620    150.86    
  120.5901    14.5913    458.7235    127.93    
  18.8061    338.1100    331.9642    171.13    
  454.6958    21.0686    131.7310    175.08    
  393.0473    77.6817    253.8350    170.88    
  ......
  </code></pre>
  
  <p>My attempts: </p>
  
  <ol>
  <li>To use pm3d, but the data is not in consecutive sequence, it didn't work. There is an error message: </li>
  </ol>
  
  <blockquote>
    <p>Gridding of the color column is not implemented.</p>
  </blockquote>
  
  <ol start="2">
  <li>To use dgrid3d, reference from <a href="https://stackoverflow.com/questions/25573139/3-dimensional-plot-in-gnuplot-where-color-is-a-fourth-column-in-my-data-file">3-Dimensional Plot in GnuPlot where color is a fourth column in my data file</a>. However, the plot I got was <a href="https://i.stack.imgur.com/uD2Pj.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/uD2Pj.png" alt="enter image description here"></a>
  this is still different from my goal. </li>
  </ol>
  
  <p>How can I plot this data successfully? </p>