public static CommonOutputs.TransformOutput Replace(IHostEnvironment env, MissingValueReplacingTransformer.Arguments input)
{
var h = EntryPointUtils.CheckArgsAndCreateHost(env, "NAReplace", input);
var xf = MissingValueReplacingTransformer.Create(h, input, input.Data);
return(new CommonOutputs.TransformOutput()
{
Model = new TransformModelImpl(h, xf, input.Data),
OutputData = xf
});
}
/// Factory method for SignatureDataTransform.
internal static IDataTransform Create(IHostEnvironment env, Options options, IDataView input)
{
Contracts.CheckValue(env, nameof(env));
var h = env.Register("Categorical");
h.CheckValue(options, nameof(options));
h.CheckValue(input, nameof(input));
h.CheckUserArg(Utils.Size(options.Columns) > 0, nameof(options.Columns));
var replaceCols = new List <MissingValueReplacingEstimator.ColumnInfo>();
var naIndicatorCols = new List <MissingValueIndicatorTransformer.Column>();
var naConvCols = new List <TypeConvertingEstimator.ColumnInfo>();
var concatCols = new List <ColumnConcatenatingTransformer.TaggedColumn>();
var dropCols = new List <string>();
var tmpIsMissingColNames = input.Schema.GetTempColumnNames(options.Columns.Length, "IsMissing");
var tmpReplaceColNames = input.Schema.GetTempColumnNames(options.Columns.Length, "Replace");
for (int i = 0; i < options.Columns.Length; i++)
{
var column = options.Columns[i];
var addInd = column.ConcatIndicator ?? options.Concat;
if (!addInd)
{
replaceCols.Add(new MissingValueReplacingEstimator.ColumnInfo(column.Name, column.Source,
(MissingValueReplacingEstimator.ColumnInfo.ReplacementMode)(column.Kind ?? options.ReplaceWith), column.ImputeBySlot ?? options.ImputeBySlot));
continue;
}
// Check that the indicator column has a type that can be converted to the NAReplaceTransform output type,
// so that they can be concatenated.
if (!input.Schema.TryGetColumnIndex(column.Source, out int inputCol))
{
throw h.Except("Column '{0}' does not exist", column.Source);
}
var replaceType = input.Schema[inputCol].Type;
var replaceItemType = replaceType.GetItemType();
if (!Data.Conversion.Conversions.Instance.TryGetStandardConversion(BooleanDataViewType.Instance, replaceItemType, out Delegate conv, out bool identity))
{
throw h.Except("Cannot concatenate indicator column of type '{0}' to input column of type '{1}'",
BooleanDataViewType.Instance, replaceItemType);
}
// Find a temporary name for the NAReplaceTransform and NAIndicatorTransform output columns.
var tmpIsMissingColName = tmpIsMissingColNames[i];
var tmpReplacementColName = tmpReplaceColNames[i];
// Add an NAHandleTransform column.
naIndicatorCols.Add(new MissingValueIndicatorTransformer.Column()
{
Name = tmpIsMissingColName, Source = column.Source
});
// Add a ConvertTransform column if necessary.
if (!identity)
{
if (!replaceItemType.RawType.TryGetDataKind(out DataKind replaceItemTypeKind))
{
throw h.Except("Cannot get a DataKind for type '{0}'", replaceItemType.RawType);
}
naConvCols.Add(new TypeConvertingEstimator.ColumnInfo(tmpIsMissingColName, replaceItemTypeKind, tmpIsMissingColName));
}
// Add the NAReplaceTransform column.
replaceCols.Add(new MissingValueReplacingEstimator.ColumnInfo(tmpReplacementColName, column.Source,
(MissingValueReplacingEstimator.ColumnInfo.ReplacementMode)(column.Kind ?? options.ReplaceWith), column.ImputeBySlot ?? options.ImputeBySlot));
// Add the ConcatTransform column.
if (replaceType is VectorType)
{
concatCols.Add(new ColumnConcatenatingTransformer.TaggedColumn()
{
Name = column.Name,
Source = new[] {
new KeyValuePair <string, string>(tmpReplacementColName, tmpReplacementColName),
new KeyValuePair <string, string>("IsMissing", tmpIsMissingColName)
}
});
}
else
{
concatCols.Add(new ColumnConcatenatingTransformer.TaggedColumn()
{
Name = column.Name,
Source = new[]
{
new KeyValuePair <string, string>(column.Source, tmpReplacementColName),
new KeyValuePair <string, string>(string.Format("IsMissing.{0}", column.Source), tmpIsMissingColName),
}
});
}
// Add the temp column to the list of columns to drop at the end.
dropCols.Add(tmpIsMissingColName);
dropCols.Add(tmpReplacementColName);
}
IDataTransform output = null;
// Create the indicator columns.
if (naIndicatorCols.Count > 0)
{
output = MissingValueIndicatorTransformer.Create(h, new MissingValueIndicatorTransformer.Options()
{
Columns = naIndicatorCols.ToArray()
}, input);
}
// Convert the indicator columns to the correct type so that they can be concatenated to the NAReplace outputs.
if (naConvCols.Count > 0)
{
h.AssertValue(output);
//REVIEW: all this need to be converted to estimatorChain as soon as we done with dropcolumns.
output = new TypeConvertingTransformer(h, naConvCols.ToArray()).Transform(output) as IDataTransform;
}
// Create the NAReplace transform.
output = MissingValueReplacingTransformer.Create(env, output ?? input, replaceCols.ToArray());
// Concat the NAReplaceTransform output and the NAIndicatorTransform output.
if (naIndicatorCols.Count > 0)
{
output = ColumnConcatenatingTransformer.Create(h, new ColumnConcatenatingTransformer.TaggedOptions()
{
Columns = concatCols.ToArray()
}, output);
}
// Finally, drop the temporary indicator columns.
if (dropCols.Count > 0)
{
output = ColumnSelectingTransformer.CreateDrop(h, output, dropCols.ToArray()) as IDataTransform;
}
return(output);
}
