title: Why do I get odd 0,0 point in Octave trisurf
body: <p><a href="https://i.stack.imgur.com/g4bkD.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/g4bkD.png" alt="enter image description here"></a></p>
  
  <p>I am trying to draw a surface from a file on disk (shown below). But I get an odd additional point at co-ords (0,0).</p>
  
  <p>The file appears to be in correct shape to me.</p>
  
  <p>I draw the chart from my C# application with a call to Octave .Net. Here is the Octave part of the script:</p>
  
  <pre><code>figure (1,'name','Map');
  colormap('hot');
  
  t = dlmread('C:\Map3D.csv');
  # idx = find(t(:,4) == 4.0);t2 = t(idx,:);
  tx =t(:,1);ty=t(:,2);tz=t(:,3);
  tri = delaunay(tx,ty);
  
  handle = trisurf(tri,tx,ty,tz);xlabel('Floor');ylabel('HurdleF');zlabel('Sharpe');
  
  waitfor(handle); 
  </code></pre>
  
  <p>This script is called from my C# app, with the following , very simple, code snippet:</p>
  
  <pre><code>using (var octave = new OctaveContext())
  {
      octave.Execute(script, int.MaxValue);
  }
  </code></pre>
  
  <p>Can anyone explain if my Octave script is wrong, or the way I have structured the file.</p>
  
  <pre><code>Floor,HurdleF,Sharpe,Model
  1.40000000,15.00000000,-0.44,xxx1.40_Hrd_15.00
  1.40000000,14.00000000,-0.49,xxx1.40_Hrd_14.00
  1.40000000,13.00000000,-0.19,xxx1.40_Hrd_13.00
  1.40000000,12.00000000,-0.41,xxx1.40_Hrd_12.00
  1.40000000,11.00000000,0.42,xxx1.40_Hrd_11.00
  1.40000000,10.00000000,0.17,xxx1.40_Hrd_10.00
  1.40000000,9.00000000,0.28,xxx1.40_Hrd_9.00
  1.40000000,8.00000000,0.49,xxx1.40_Hrd_8.00
  1.40000000,7.00000000,0.45,xxx1.40_Hrd_7.00
  1.40000000,6.00000000,0.79,xxx1.40_Hrd_6.00
  1.40000000,5.00000000,0.56,xxx1.40_Hrd_5.00
  1.40000000,4.00000000,1.76,xxx1.40_Hrd_4.00
  1.30000000,15.00000000,-0.46,xxx1.30_Hrd_15.00
  1.30000000,14.00000000,-0.55,xxx1.30_Hrd_14.00
  1.30000000,13.00000000,-0.24,xxx1.30_Hrd_13.00
  1.30000000,12.00000000,0.35,xxx1.30_Hrd_12.00
  1.30000000,11.00000000,0.08,xxx1.30_Hrd_11.00
  1.30000000,10.00000000,0.63,xxx1.30_Hrd_10.00
  1.30000000,9.00000000,0.83,xxx1.30_Hrd_9.00
  1.30000000,8.00000000,0.21,xxx1.30_Hrd_8.00
  1.30000000,7.00000000,0.55,xxx1.30_Hrd_7.00
  1.30000000,6.00000000,0.63,xxx1.30_Hrd_6.00
  1.30000000,5.00000000,0.93,xxx1.30_Hrd_5.00
  1.30000000,4.00000000,2.50,xxx1.30_Hrd_4.00
  1.20000000,15.00000000,-0.40,xxx1.20_Hrd_15.00
  1.20000000,14.00000000,-0.69,xxx1.20_Hrd_14.00
  1.20000000,13.00000000,0.23,xxx1.20_Hrd_13.00
  1.20000000,12.00000000,0.56,xxx1.20_Hrd_12.00
  1.20000000,11.00000000,0.22,xxx1.20_Hrd_11.00
  1.20000000,10.00000000,0.56,xxx1.20_Hrd_10.00
  1.20000000,9.00000000,0.79,xxx1.20_Hrd_9.00
  1.20000000,8.00000000,0.20,xxx1.20_Hrd_8.00
  1.20000000,7.00000000,1.09,xxx1.20_Hrd_7.00
  1.20000000,6.00000000,0.99,xxx1.20_Hrd_6.00
  1.20000000,5.00000000,1.66,xxx1.20_Hrd_5.00
  1.20000000,4.00000000,2.23,xxx1.20_Hrd_4.00
  1.10000000,15.00000000,-0.31,xxx1.10_Hrd_15.00
  1.10000000,14.00000000,-0.18,xxx1.10_Hrd_14.00
  1.10000000,13.00000000,0.24,xxx1.10_Hrd_13.00
  1.10000000,12.00000000,0.70,xxx1.10_Hrd_12.00
  1.10000000,11.00000000,0.31,xxx1.10_Hrd_11.00
  1.10000000,10.00000000,0.76,xxx1.10_Hrd_10.00
  1.10000000,9.00000000,1.24,xxx1.10_Hrd_9.00
  1.10000000,8.00000000,0.94,xxx1.10_Hrd_8.00
  1.10000000,7.00000000,1.09,xxx1.10_Hrd_7.00
  1.10000000,6.00000000,1.53,xxx1.10_Hrd_6.00
  1.10000000,5.00000000,2.41,xxx1.10_Hrd_5.00
  1.10000000,4.00000000,2.16,xxx1.10_Hrd_4.00
  1.00000000,15.00000000,-0.41,xxx1.00_Hrd_15.00
  1.00000000,14.00000000,-0.24,xxx1.00_Hrd_14.00
  1.00000000,13.00000000,0.33,xxx1.00_Hrd_13.00
  1.00000000,12.00000000,0.18,xxx1.00_Hrd_12.00
  1.00000000,11.00000000,0.61,xxx1.00_Hrd_11.00
  1.00000000,10.00000000,0.96,xxx1.00_Hrd_10.00
  1.00000000,9.00000000,1.75,xxx1.00_Hrd_9.00
  1.00000000,8.00000000,0.74,xxx1.00_Hrd_8.00
  1.00000000,7.00000000,1.63,xxx1.00_Hrd_7.00
  1.00000000,6.00000000,2.12,xxx1.00_Hrd_6.00
  1.00000000,5.00000000,2.73,xxx1.00_Hrd_5.00
  1.00000000,4.00000000,2.03,xxx1.00_Hrd_4.00
  0.90000000,15.00000000,-0.42,xxx0.90_Hrd_15.00
  0.90000000,14.00000000,-0.37,xxx0.90_Hrd_14.00
  0.90000000,13.00000000,0.58,xxx0.90_Hrd_13.00
  0.90000000,12.00000000,0.03,xxx0.90_Hrd_12.00
  0.90000000,11.00000000,0.68,xxx0.90_Hrd_11.00
  0.90000000,10.00000000,0.79,xxx0.90_Hrd_10.00
  0.90000000,9.00000000,1.54,xxx0.90_Hrd_9.00
  0.90000000,8.00000000,0.82,xxx0.90_Hrd_8.00
  0.90000000,7.00000000,1.81,xxx0.90_Hrd_7.00
  0.90000000,6.00000000,2.33,xxx0.90_Hrd_6.00
  0.90000000,5.00000000,2.99,xxx0.90_Hrd_5.00
  0.90000000,4.00000000,1.71,xxx0.90_Hrd_4.00
  0.80000000,15.00000000,-0.46,xxx0.80_Hrd_15.00
  0.80000000,14.00000000,-0.26,xxx0.80_Hrd_14.00
  0.80000000,13.00000000,0.55,xxx0.80_Hrd_13.00
  0.80000000,12.00000000,0.07,xxx0.80_Hrd_12.00
  0.80000000,11.00000000,0.65,xxx0.80_Hrd_11.00
  0.80000000,10.00000000,1.08,xxx0.80_Hrd_10.00
  0.80000000,9.00000000,1.27,xxx0.80_Hrd_9.00
  0.80000000,8.00000000,1.12,xxx0.80_Hrd_8.00
  0.80000000,7.00000000,1.98,xxx0.80_Hrd_7.00
  0.80000000,6.00000000,2.62,xxx0.80_Hrd_6.00
  0.80000000,5.00000000,3.35,xxx0.80_Hrd_5.00
  0.80000000,4.00000000,1.27,xxx0.80_Hrd_4.00
  0.70000000,15.00000000,-0.56,xxx0.70_Hrd_15.00
  0.70000000,14.00000000,-0.33,xxx0.70_Hrd_14.00
  0.70000000,13.00000000,0.24,xxx0.70_Hrd_13.00
  0.70000000,12.00000000,-0.22,xxx0.70_Hrd_12.00
  0.70000000,11.00000000,0.74,xxx0.70_Hrd_11.00
  0.70000000,10.00000000,1.19,xxx0.70_Hrd_10.00
  0.70000000,9.00000000,1.24,xxx0.70_Hrd_9.00
  0.70000000,8.00000000,1.14,xxx0.70_Hrd_8.00
  0.70000000,7.00000000,2.26,xxx0.70_Hrd_7.00
  0.70000000,6.00000000,2.70,xxx0.70_Hrd_6.00
  0.70000000,5.00000000,3.52,xxx0.70_Hrd_5.00
  0.70000000,4.00000000,1.05,xxx0.70_Hrd_4.00
  0.60000000,15.00000000,-0.50,xxx0.60_Hrd_15.00
  0.60000000,14.00000000,-0.60,xxx0.60_Hrd_14.00
  0.60000000,13.00000000,0.11,xxx0.60_Hrd_13.00
  0.60000000,12.00000000,-0.16,xxx0.60_Hrd_12.00
  0.60000000,11.00000000,0.73,xxx0.60_Hrd_11.00
  0.60000000,10.00000000,1.08,xxx0.60_Hrd_10.00
  0.60000000,9.00000000,1.31,xxx0.60_Hrd_9.00
  0.60000000,8.00000000,1.38,xxx0.60_Hrd_8.00
  0.60000000,7.00000000,2.24,xxx0.60_Hrd_7.00
  0.60000000,6.00000000,2.89,xxx0.60_Hrd_6.00
  0.60000000,5.00000000,3.50,xxx0.60_Hrd_5.00
  0.60000000,4.00000000,1.11,xxx0.60_Hrd_4.00
  0.50000000,15.00000000,-0.40,xxx0.50_Hrd_15.00
  0.50000000,14.00000000,-0.37,xxx0.50_Hrd_14.00
  0.50000000,13.00000000,0.13,xxx0.50_Hrd_13.00
  0.50000000,12.00000000,-0.11,xxx0.50_Hrd_12.00
  0.50000000,11.00000000,0.61,xxx0.50_Hrd_11.00
  0.50000000,10.00000000,0.92,xxx0.50_Hrd_10.00
  0.50000000,9.00000000,1.41,xxx0.50_Hrd_9.00
  0.50000000,8.00000000,1.39,xxx0.50_Hrd_8.00
  0.50000000,7.00000000,2.19,xxx0.50_Hrd_7.00
  0.50000000,6.00000000,2.80,xxx0.50_Hrd_6.00
  0.50000000,5.00000000,3.41,xxx0.50_Hrd_5.00
  0.50000000,4.00000000,1.05,xxx0.50_Hrd_4.00
  0.40000000,15.00000000,-0.25,xxx0.40_Hrd_15.00
  0.40000000,14.00000000,-0.44,xxx0.40_Hrd_14.00
  0.40000000,13.00000000,0.02,xxx0.40_Hrd_13.00
  0.40000000,12.00000000,0.00,xxx0.40_Hrd_12.00
  0.40000000,11.00000000,0.69,xxx0.40_Hrd_11.00
  0.40000000,10.00000000,0.67,xxx0.40_Hrd_10.00
  0.40000000,9.00000000,1.02,xxx0.40_Hrd_9.00
  0.40000000,8.00000000,1.29,xxx0.40_Hrd_8.00
  0.40000000,7.00000000,2.17,xxx0.40_Hrd_7.00
  0.40000000,6.00000000,2.88,xxx0.40_Hrd_6.00
  0.40000000,5.00000000,3.19,xxx0.40_Hrd_5.00
  0.40000000,4.00000000,0.98,xxx0.40_Hrd_4.00
  0.30000000,15.00000000,-0.02,xxx0.30_Hrd_15.00
  0.30000000,14.00000000,-0.36,xxx0.30_Hrd_14.00
  0.30000000,13.00000000,-0.26,xxx0.30_Hrd_13.00
  0.30000000,12.00000000,-0.11,xxx0.30_Hrd_12.00
  0.30000000,11.00000000,0.50,xxx0.30_Hrd_11.00
  0.30000000,10.00000000,0.50,xxx0.30_Hrd_10.00
  0.30000000,9.00000000,1.01,xxx0.30_Hrd_9.00
  0.30000000,8.00000000,1.28,xxx0.30_Hrd_8.00
  0.30000000,7.00000000,2.11,xxx0.30_Hrd_7.00
  0.30000000,6.00000000,2.89,xxx0.30_Hrd_6.00
  0.30000000,5.00000000,3.16,xxx0.30_Hrd_5.00
  0.30000000,4.00000000,0.95,xxx0.30_Hrd_4.00
  </code></pre>