title: Can I use filled.contour to plot data with decimal cartesian coordinates?
body: <p>I have a 288000x3 matrix (288000 rows, 3 columns) of x and y cartesian coordinates from -60 to 60 with decimals that trail to 8 places along with a value at those coordinates. </p>
  
  <p>Example-</p>
  
  <pre><code>        y.cart     x.cart      value
  [1,] 0.001308930 0.07498858  -49.36752
  [2,] 0.002617462 0.07495431  -48.33903
  [3,] 0.003925197 0.07489722  -51.42450
  [4,] 0.005231736 0.07481730  -51.93874
  [5,] 0.006536681 0.07471460 -513.73075
  [6,] 0.007839635 0.07458914  -52.45299
  [7,] 0.009140201 0.07444096  -51.93874
  [8,] 0.010437983 0.07427011  -48.85327
  [9,] 0.011732585 0.07407663  -49.36752
  [10,] 0.013023613 0.07386058  -50.91025
  </code></pre>
  
  <p>This is weather radar reflectivity data and I need to plot it to look like the output that filled.contour creates, but in order to use filled.contour, the values need to be in a matrix because the function uses the matrix position as the coordinates for the plot which doesn't work with the way that my data is organized. Is there a way to use a filled.contour with the data in this form or, is there another way to do this? I've been fiddling with it for two days and haven't gotten very far. Any help would be greatly appreciated.</p>