title: ML.net - Bad value at line 1 in column label
body: <p>I am following the <a href="https://www.microsoft.com/net/learn/apps/machine-learning-and-ai/ml-dotnet/get-started/windows" rel="nofollow noreferrer">Iris tutorial</a> for ML.Net, I typed out the instructions instead of copy/pasting them so I could learn the API better, but now I am getting some errors.  </p>
  
  <p>When I run this line from the tutorial a <code>System.Reflection.TargetInvocationException</code> is thrown:</p>
  
  <pre><code>var model = pipeline.Train&lt;IrisData, IrisPrediction&gt;();
  </code></pre>
  
  <p>The console errors I am getting during runtime are: </p>
  
  <pre><code>  Bad value at line 2 in column Label
    ...
    Bad value at line 8 in column Label
    Suppressing further bad value messages
    ...
  Processed 150 rows with 150 bad values and 0 format errors
  Warning: Term map for output column 'Label' contains no entries.
  Automatically adding a MinMax normalization transform, use 'norm=Warn' or 'norm=No' to turn this behavior off.
  Using 2 threads to train.
  Automatically choosing a check frequency of 2.
    Bad value at line 1 in column Label
    ...
    Suppressing further bad value messages
  Processed 150 rows with 150 bad values and 0 format errors
  Warning: Skipped 150 instances with missing features/label during training
  </code></pre>
  
  <p>Here is my <code>IrisData</code> class:</p>
  
  <pre><code>namespace Ronald.A.Fisher
  {
      public class IrisData
      {
          [Column("0")]
          public float SepalLength;
          [Column("1")]
          public float SepalWidth;
          [Column("2")]
          public float PetalLength;
          [Column("3")]
          public float PetalWidth;
          [Column("4")]
          [ColumnName("Label")]
          public float Label;
      }
  </code></pre>